1
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Yang T, Qin Y, Wu M, Guo L, Gu X, Meng K, Hu S, Zhang C, Zheng R, Zhang R, Sun X. Structural Isomeric Effect on Spin Transport in Molecular Semiconductors. Adv Mater 2024:e2402001. [PMID: 38597787 DOI: 10.1002/adma.202402001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/27/2024] [Indexed: 04/11/2024]
Abstract
Molecular semiconductor (MSC) is a promising candidate for spintronic applications benefiting from its long spin lifetime caused by light elemental-composition essence and thus weak spin-orbit coupling (SOC). According to current knowledge, the SOC effect, normally dominated by the elemental composition, is the main spin-relaxation causation in MSCs, and thus the molecular structure-induced SOC change is one of the most concerned issues. In theoretical study, molecular isomerism, a most prototype phenomenon, has long been considered to possess little difference on spin transport previously, since elemental compositions of isomers are totally the same. However, here in this study, quite different spin-transport performances are demonstrated in ITIC and its structural isomers BDTIC experimentally, for the first time, though the charge transport and molecular stacking of the two films are very similar. By further experiments of electron-paramagnetic resonance and density-functional-theory calculations, it is revealed that noncovalent-conformational locks (NCLs) formed in BDTIC can lead to enhancement of SOC and thus decrease the spin lifetime. Hence, this study suggests the influences from the structural-isomeric effect must be considered for developing highly efficient spin-transport MSCs, which also provides a reliable theoretical basis for solving the great challenge of quantificational measurement of NCLs in films in the future.
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Affiliation(s)
- Tingting Yang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Yang Qin
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Meng Wu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Lidan Guo
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xianrong Gu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Ke Meng
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Shunhua Hu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Cheng Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Ruiheng Zheng
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Rui Zhang
- Beijing Key Laboratory of Microstructure and Property of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, P. R. China
| | - Xiangnan Sun
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- School of Material Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
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2
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Giaconi N, Poggini L, Lupi M, Briganti M, Kumar A, Das TK, Sorrentino AL, Viglianisi C, Menichetti S, Naaman R, Sessoli R, Mannini M. Efficient Spin-Selective Electron Transport at Low Voltages of Thia-Bridged Triarylamine Hetero[4]helicenes Chemisorbed Monolayer. ACS Nano 2023; 17:15189-15198. [PMID: 37493644 PMCID: PMC10416567 DOI: 10.1021/acsnano.3c04878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/20/2023] [Indexed: 07/27/2023]
Abstract
The Chirality Induced Spin Selectivity (CISS) effect describes the capability of chiral molecules to act as spin filters discriminating flowing electrons according to their spin state. Within molecular spintronics, efforts are focused on developing chiral-molecule-based technologies to control the injection and coherence of spin-polarized currents. Herein, for this purpose, we study spin selectivity properties of a monolayer of a thioalkyl derivative of a thia-bridged triarylamine hetero[4]helicene chemisorbed on a gold surface. A stacked device assembled by embedding a monolayer of these molecules between ferromagnetic and diamagnetic electrodes exhibits asymmetric magnetoresistance with inversion of the signal according to the handedness of molecules, in line with the presence of the CISS effect. In addition, magnetically conductive atomic force microscopy reveals efficient electron spin filtering even at unusually low potentials. Our results demonstrate that thia[4]heterohelicenes represent key candidates for the development of chiral spintronic devices.
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Affiliation(s)
- Niccolò Giaconi
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Lorenzo Poggini
- Istituto
di Chimica dei Composti Organo-Metallici (ICCOM-CNR), Via Madonna del Piano 10, Sesto Fiorentino 50019, Italy
| | - Michela Lupi
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Matteo Briganti
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Anil Kumar
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Tapan K. Das
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Andrea L. Sorrentino
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Caterina Viglianisi
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Stefano Menichetti
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Ron Naaman
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Roberta Sessoli
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
| | - Matteo Mannini
- Department
of Chemistry “Ugo Schiff” (DICUS) & INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy
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3
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Bhandary S, Poli E, Teobaldi G, O’Regan DD. Dynamical Screening of Local Spin Moments at Metal-Molecule Interfaces. ACS Nano 2023; 17:5974-5983. [PMID: 36881865 PMCID: PMC10062023 DOI: 10.1021/acsnano.3c00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Transition-metal phthalocyanine molecules have attracted considerable interest in the context of spintronics device development due to their amenability to diverse bonding regimes and their intrinsic magnetism. The latter is highly influenced by the quantum fluctuations that arise at the inevitable metal-molecule interface in a device architecture. In this study, we have systematically investigated the dynamical screening effects in phthalocyanine molecules hosting a series of transition-metal ions (Ti, V, Cr, Mn, Fe, Co, and Ni) in contact with the Cu(111) surface. Using comprehensive density functional theory plus Anderson's Impurity Model calculations, we show that the orbital-dependent hybridization and electron correlation together result in strong charge and spin fluctuations. While the instantaneous spin moments of the transition-metal ions are near atomic-like, we find that screening gives rise to considerable lowering or even quenching of these. Our results highlight the importance of quantum fluctuations in metal-contacted molecular devices, which may influence the results obtained from theoretical or experimental probes, depending on their possibly material-dependent characteristic sampling time-scales.
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Affiliation(s)
- Sumanta Bhandary
- School
of Physics and CRANN Institute, Trinity
College Dublin, The University
of Dublin, Dublin 2, Ireland
| | - Emiliano Poli
- Scientific
Computing Department, STFC UKRI, Rutherford
Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Gilberto Teobaldi
- Scientific
Computing Department, STFC UKRI, Rutherford
Appleton Laboratory, Didcot OX11 0QX, United Kingdom
- School
of Chemistry, University of Southampton, Highfield SO17 1BJ, Southampton, United Kingdom
| | - David D. O’Regan
- School
of Physics and CRANN Institute, Trinity
College Dublin, The University
of Dublin, Dublin 2, Ireland
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4
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Wolf Y, Liu Y, Xiao J, Park N, Yan B. Unusual Spin Polarization in the Chirality-Induced Spin Selectivity. ACS Nano 2022; 16:18601-18607. [PMID: 36282509 PMCID: PMC9706810 DOI: 10.1021/acsnano.2c07088] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 09/29/2022] [Indexed: 06/07/2023]
Abstract
Chirality-induced spin selectivity (CISS) refers to the fact that electrons get spin polarized after passing through chiral molecules in a nanoscale transport device or in photoemission experiments. In CISS, chiral molecules are commonly believed to be a spin filter through which one favored spin transmits and the opposite spin gets reflected; that is, transmitted and reflected electrons exhibit opposite spin polarization. In this work, we point out that such a spin filter scenario contradicts the principle that equilibrium spin current must vanish. Instead, we find that both transmitted and reflected electrons present the same type of spin polarization, which is actually ubiquitous for a two-terminal device. More accurately, chiral molecules play the role of a spin polarizer rather than a spin filter. The direction of spin polarization is determined by the molecule chirality and the electron incident direction. And the magnitude of spin polarization relies on local spin-orbit coupling in the device. Our work brings a deeper understanding on CISS and interprets recent experiments, for example, the CISS-driven anomalous Hall effect.
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Affiliation(s)
- Yotam Wolf
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
| | - Yizhou Liu
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
| | - Jiewen Xiao
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
| | - Noejung Park
- Department
of Physics, Ulsan National Institute of
Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Binghai Yan
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
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5
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Bergenti I, Kamiya T, Li D, Riminucci A, Graziosi P, MacLaren DA, Rakshit RK, Singh M, Benini M, Tada H, Smogunov A, Dediu VA. Spinterface Effects in Hybrid La 0.7Sr 0.3MnO 3/SrTiO 3/C 60/Co Magnetic Tunnel Junctions. ACS Appl Electron Mater 2022; 4:4273-4279. [PMID: 36193212 PMCID: PMC9523579 DOI: 10.1021/acsaelm.2c00300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 08/10/2022] [Indexed: 06/16/2023]
Abstract
Orbital hybridization at the Co/C60 interface been has proved to strongly enhance the magnetic anisotropy of the cobalt layer, promoting such hybrid systems as appealing components for sensing and memory devices. Correspondingly, the same hybridization induces substantial variations in the ability of the Co/C60 interface to support spin-polarized currents and can bring out a spin-filtering effect. The knowledge of the effects at both sides allows for a better and more complete understanding of interfacial physics. In this paper we investigate the Co/C60 bilayer in the role of a spin-polarized electrode in the La0.7Sr0.3MnO3/SrTiO3/C60/Co configuration, thus substituting the bare Co electrode in the well-known La0.7Sr0.3MnO3/SrTiO3/Co magnetic tunnel junction. The study revealed that the spin polarization (SP) of the tunneling currents escaping from the Co/C60 electrode is generally negative: i.e., inverted with respect to the expected SP of the Co electrode. The observed sign of the spin polarization was confirmed via DFT calculations by considering the hybridization between cobalt and molecular orbitals.
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Affiliation(s)
- Ilaria Bergenti
- Institute
of Nanostructured Materials ISMN-CNR, Via Gobetti 101, Bologna 40129, Italy
| | - Takeshi Kamiya
- Department
of Materials Engineering Science, Osaka
University, 1-3, Machikaneyama, Toyonaka, Osaka, Japan 560-8531
| | - Dongzhe Li
- CEMES,
Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Alberto Riminucci
- Institute
of Nanostructured Materials ISMN-CNR, Via Gobetti 101, Bologna 40129, Italy
| | - Patrizio Graziosi
- Institute
of Nanostructured Materials ISMN-CNR, Via Gobetti 101, Bologna 40129, Italy
| | - Donald A. MacLaren
- SUPA,
School of Physics and Astronomy, University
of Glasgow, Glasgow G12 8QQ, U.K.
| | - Rajib K. Rakshit
- CSIR
- National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India
| | - Manju Singh
- CSIR
- National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India
| | - Mattia Benini
- Institute
of Nanostructured Materials ISMN-CNR, Via Gobetti 101, Bologna 40129, Italy
| | - Hirokazu Tada
- Department
of Materials Engineering Science, Osaka
University, 1-3, Machikaneyama, Toyonaka, Osaka, Japan 560-8531
| | - Alexander Smogunov
- Service de
Physique de l’Etat Condensé (SPEC), CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette
Cedex France
| | - Valentin A. Dediu
- Institute
of Nanostructured Materials ISMN-CNR, Via Gobetti 101, Bologna 40129, Italy
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6
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Gavara-Edo M, Córdoba R, Valverde-Muñoz FJ, Herrero-Martín J, Real JA, Coronado E. Electrical Sensing of the Thermal and Light-Induced Spin Transition in Robust Contactless Spin-Crossover/Graphene Hybrid Devices. Adv Mater 2022; 34:e2202551. [PMID: 35766419 DOI: 10.1002/adma.202202551] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Hybrid devices based on spin-crossover (SCO)/2D heterostructures grant a highly sensitive platform to detect the spin transition in the molecular SCO component and tune the properties of the 2D material. However, the fragility of the SCO materials upon thermal treatment, light irradiation, or contact with surfaces and the methodologies used for their processing have limited their applicability. Here, an easily processable and robust SCO/2D hybrid device with outstanding performance based on the sublimable SCO [Fe(Pyrz)2 ] molecule deposited over chemical vapor deposition (CVD) graphene is reported, which is fully compatible with electronics industry protocols. Thus, a novel methodology based on growing an elusive polymorph of [Fe(Pyrz)2 ] (tetragonal phase) over graphene is developed that allows a fast and effective light-induced spin transition in the devices (≈50% yield in 5 min) to be detected electrically. Such performance can be enhanced even more when a flexible polymeric layer of poly(methyl methacrylate) is inserted in between the two active components in a contactless configuration, reaching a ≈100% yield in 5 min.
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Affiliation(s)
- Miguel Gavara-Edo
- Institute of Molecular Science, University of Valencia, Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Rosa Córdoba
- Institute of Molecular Science, University of Valencia, Catedrático José Beltrán 2, Paterna, 46980, Spain
| | | | | | - José Antonio Real
- Institute of Molecular Science, University of Valencia, Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Eugenio Coronado
- Institute of Molecular Science, University of Valencia, Catedrático José Beltrán 2, Paterna, 46980, Spain
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7
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Aggarwal A, Kaliginedi V, Maiti PK. Quantum Circuit Rules for Molecular Electronic Systems: Where Are We Headed Based on the Current Understanding of Quantum Interference, Thermoelectric, and Molecular Spintronics Phenomena? Nano Lett 2021; 21:8532-8544. [PMID: 34622657 DOI: 10.1021/acs.nanolett.1c02390] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this minireview, we discuss important aspects of the various quantum phenomena (such as quantum interference, spin-dependent charge transport, and thermoelectric effects) relevant in single-molecule charge transport and list some of the basic circuit rules devised for different molecular systems. These quantum phenomena, in conjunction with the existing empirical circuit rules, can help in predicting some of the structure-property relationships in molecular circuits. However, a universal circuit law that predicts the charge transport properties of a molecular circuit has not been derived yet. Having such law(s) will help to design and build a complex molecular device leading to exciting unique applications that are not possible with the traditional silicon-based technologies. Based on the existing knowledge in the literature, here we open the discussion on the possible future research directions for deriving unified circuit law(s) to predict the charge transport in complex single-molecule circuits.
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Affiliation(s)
- Abhishek Aggarwal
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Veerabhadrarao Kaliginedi
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Prabal K Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
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8
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Kipgen L, Bernien M, Tuczek F, Kuch W. Spin-Crossover Molecules on Surfaces: From Isolated Molecules to Ultrathin Films. Adv Mater 2021; 33:e2008141. [PMID: 33963619 DOI: 10.1002/adma.202008141] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Molecular spintronics seeks to use single or few molecules as functional building blocks for spintronic applications, directly relying on molecular properties or properties of interfaces between molecules and inorganic electrodes. Spin-crossover molecules (SCMs) are one of the most promising classes of candidates for molecular spintronics due to their bistability deriving from the existence of two spin states that can be reversibly switched by temperature, light, electric fields, etc. Building devices based on single or few molecules would entail connecting the molecule(s) with solid surfaces and understanding the fundamental behavior of the resulting assemblies. Herein, the investigations of SCMs on solid surfaces, ranging from isolated single molecules (submonolayers) to ultrathin films (mainly in the sub-10 nm range) are summarized. The achievements, challenges and prospects in this field are highlighted.
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Affiliation(s)
- Lalminthang Kipgen
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Matthias Bernien
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118, Kiel, Germany
| | - Wolfgang Kuch
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
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9
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Cojocariu I, Carlotto S, Sturmeit HM, Zamborlini G, Cinchetti M, Cossaro A, Verdini A, Floreano L, Jugovac M, Puschnig P, Piamonteze C, Casarin M, Feyer V, Schneider CM. Ferrous to Ferric Transition in Fe-Phthalocyanine Driven by NO 2 Exposure. Chemistry 2021; 27:3526-3535. [PMID: 33264485 PMCID: PMC7898877 DOI: 10.1002/chem.202004932] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Indexed: 01/10/2023]
Abstract
Due to its unique magnetic properties offered by the open‐shell electronic structure of the central metal ion, and for being an effective catalyst in a wide variety of reactions, iron phthalocyanine has drawn significant interest from the scientific community. Nevertheless, upon surface deposition, the magnetic properties of the molecular layer can be significantly affected by the coupling occurring at the interface, and the more reactive the surface, the stronger is the impact on the spin state. Here, we show that on Cu(100), indeed, the strong hybridization between the Fe d‐states of FePc and the sp‐band of the copper substrate modifies the charge distribution in the molecule, significantly influencing the magnetic properties of the iron ion. The FeII ion is stabilized in the low singlet spin state (S=0), leading to the complete quenching of the molecule magnetic moment. By exploiting the FePc/Cu(100) interface, we demonstrate that NO2 dissociation can be used to gradually change the magnetic properties of the iron ion, by trimming the gas dosage. For lower doses, the FePc film is decoupled from the copper substrate, restoring the gas phase triplet spin state (S=1). A higher dose induces the transition from ferrous to ferric phthalocyanine, in its intermediate spin state, with enhanced magnetic moment due to the interaction with the atomic ligands. Remarkably, in this way, three different spin configurations have been observed within the same metalorganic/metal interface by exposing it to different doses of NO2 at room temperature.
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Affiliation(s)
- Iulia Cojocariu
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52428, Jülich, Germany
| | - Silvia Carlotto
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via F. Marzolo 1, 35131, Padova, Italy
| | | | - Giovanni Zamborlini
- Technische Universität Dortmund, Experimentelle Physik VI, Otto-Hahn-Straße 4, 44227, Dortmund, Germany
| | - Mirko Cinchetti
- Technische Universität Dortmund, Experimentelle Physik VI, Otto-Hahn-Straße 4, 44227, Dortmund, Germany
| | - Albano Cossaro
- CNR-IOM, Lab. TASC, S.S. 14, Km. 163,5, 34149, Trieste, Italy
| | - Alberto Verdini
- CNR-IOM, Lab. TASC, S.S. 14, Km. 163,5, 34149, Trieste, Italy
| | - Luca Floreano
- CNR-IOM, Lab. TASC, S.S. 14, Km. 163,5, 34149, Trieste, Italy
| | - Matteo Jugovac
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52428, Jülich, Germany.,Present address: Istituto di Struttura della Materia-CNR (ISM-CNR), S.S. 14, Km. 163,5, 34149, Trieste, Italy
| | - Peter Puschnig
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010, Graz, Austria
| | - Cinthia Piamonteze
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Maurizio Casarin
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via F. Marzolo 1, 35131, Padova, Italy
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52428, Jülich, Germany.,Fakultät für Physik and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, Carl-Benz-Straße 199, 47047, Duisburg, Germany
| | - Claus Michael Schneider
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52428, Jülich, Germany.,Fakultät für Physik and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, Carl-Benz-Straße 199, 47047, Duisburg, Germany
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10
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Alotibi S, Hickey BJ, Teobaldi G, Ali M, Barker J, Poli E, O'Regan DD, Ramasse Q, Burnell G, Patchett J, Ciccarelli C, Alyami M, Moorsom T, Cespedes O. Enhanced Spin-Orbit Coupling in Heavy Metals via Molecular Coupling. ACS Appl Mater Interfaces 2021; 13:5228-5234. [PMID: 33470108 DOI: 10.1021/acsami.0c19403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
5d metals are used in electronics because of their high spin-orbit coupling (SOC) leading to efficient spin-electric conversion. When C60 is grown on a metal, the electronic structure is altered due to hybridization and charge transfer. In this work, we measure the spin Hall magnetoresistance for Pt/C60 and Ta/C60, finding that they are up to a factor of 6 higher than those for pristine metals, indicating a 20-60% increase in the spin Hall angle. At low fields of 1-30 mT, the presence of C60 increased the anisotropic magnetoresistance by up to 700%. Our measurements are supported by noncollinear density functional theory calculations, which predict a significant SOC enhancement by C60 that penetrates through the Pt layer, concomitant with trends in the magnetic moment of transport electrons acquired via SOC and symmetry breaking. The charge transfer and hybridization between the metal and C60 can be controlled by gating, so our results indicate the possibility of dynamically modifying the SOC of thin metals using molecular layers. This could be exploited in spin-transfer torque memories and pure spin current circuits.
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Affiliation(s)
- Satam Alotibi
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Bryan J Hickey
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Gilberto Teobaldi
- Scientific Computing Department, Science and Technology Facilities Council, Didcot OX11 0QX, U.K
- Beijing Computational Science Research Center, Beijing 100193, China
- Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Mannan Ali
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Joseph Barker
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Emiliano Poli
- Scientific Computing Department, Science and Technology Facilities Council, Didcot OX11 0QX, U.K
| | - David D O'Regan
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and the SFI Advanced Materials and Bio-Engineering Research Centre (AMBER), Dublin 2, Ireland
| | - Quentin Ramasse
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
- SuperSTEM, SciTech Daresbury Science and Innovation Campus, Keckwick Lane, Daresbury WA4 4AD, U.K
| | - Gavin Burnell
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - James Patchett
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Chiara Ciccarelli
- SuperSTEM, SciTech Daresbury Science and Innovation Campus, Keckwick Lane, Daresbury WA4 4AD, U.K
| | - Mohammed Alyami
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Timothy Moorsom
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
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11
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Xu Z, Liu J, Hou S, Wang Y. Manipulation of Molecular Spin State on Surfaces Studied by Scanning Tunneling Microscopy. Nanomaterials (Basel) 2020; 10:E2393. [PMID: 33266045 DOI: 10.3390/nano10122393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022]
Abstract
The adsorbed magnetic molecules with tunable spin states have drawn wide attention for their immense potential in the emerging fields of molecular spintronics and quantum computing. One of the key issues toward their application is the efficient controlling of their spin state. This review briefly summarizes the recent progress in the field of molecular spin state manipulation on surfaces. We focus on the molecular spins originated from the unpaired electrons of which the Kondo effect and spin excitation can be detected by scanning tunneling microscopy and spectroscopy (STM and STS). Studies of the molecular spin-carriers in three categories are overviewed, i.e., the ones solely composed of main group elements, the ones comprising 3d-metals, and the ones comprising 4f-metals. Several frequently used strategies for tuning molecular spin state are exemplified, including chemical reactions, reversible atomic/molecular chemisorption, and STM-tip manipulations. The summary of the successful case studies of molecular spin state manipulation may not only facilitate the fundamental understanding of molecular magnetism and spintronics but also inspire the design of the molecule-based spintronic devices and materials.
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12
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Liu T, Wang X, Wang H, Shi G, Gao F, Feng H, Deng H, Hu L, Lochner E, Schlottmann P, von Molnár S, Li Y, Zhao J, Xiong P. Linear and Nonlinear Two-Terminal Spin-Valve Effect from Chirality-Induced Spin Selectivity. ACS Nano 2020; 14:15983-15991. [PMID: 33136367 DOI: 10.1021/acsnano.0c07438] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Various mechanisms of electrical generation of spin polarization in nonmagnetic materials have been a subject of broad interest for their underlying physics and device potential in spintronics. One such scheme is chirality-induced spin selectivity (CISS), with which structural chirality leads to different electric conductivities for electrons of opposite spins. The resulting effect of spin filtering has been reported for a number of chiral molecules assembled on different surfaces. However, the microscopic origin and transport mechanisms remain controversial. In particular, the fundamental Onsager relation was argued to preclude linear-response detection of CISS by a ferromagnet. Here, we report definitive observation of CISS-induced magnetoconductance in vertical heterojunctions of (Ga,Mn)As/AHPA-L molecules/Au, directly verifying spin filtering by the AHPA-L molecules via spin detection by the (Ga,Mn)As. The pronounced and robust magnetoconductance signals resulting from the use of a magnetic semiconductor enable a rigorous examination of its bias dependence, which shows both linear- and nonlinear-response components. The definitive identification of the linear-response CISS-induced two-terminal spin-valve effect places an important constraint for a viable theory of CISS and its device manifestations. The results present a promising route to spin injection and detection in semiconductors without using any magnetic material.
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Affiliation(s)
- Tianhan Liu
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Xiaolei Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Gang Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fan Gao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Honglei Feng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Haoyun Deng
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Longqian Hu
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Eric Lochner
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Pedro Schlottmann
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Stephan von Molnár
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Yongqing Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Beijing Academy of Quantum Information Science, Beijing 100193, China
| | - Peng Xiong
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
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13
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Cucinotta G, Poggini L, Giaconi N, Cini A, Gonidec M, Atzori M, Berretti E, Lavacchi A, Fittipaldi M, Chumakov AI, Rüffer R, Rosa P, Mannini M. Space Charge-Limited Current Transport Mechanism in Crossbar Junction Embedding Molecular Spin Crossovers. ACS Appl Mater Interfaces 2020; 12:31696-31705. [PMID: 32551478 PMCID: PMC8008390 DOI: 10.1021/acsami.0c07445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
Spin crossover complexes are among the most studied classes of molecular switches and have attracted considerable attention for their potential technological use as active units in multifunctional devices. A fundamental step toward their practical implementation is the integration in macroscopic devices adopting hybrid vertical architectures. First, the physical properties of technological interest shown by these materials in the bulk phase have to be retained once they are deposited on a solid surface. Herein, we describe the study of a hybrid molecular inorganic junction embedding the spin crossover complex [Fe(qnal)2] (qnal = quinoline-naphthaldehyde) as an active switchable thin film sandwiched within energy-optimized metallic electrodes. In these junctions, developed and characterized with the support of state of the art techniques including synchrotron Mössbauer source (SMS) spectroscopy and focused-ion beam scanning transmission electron microscopy, we observed that the spin state conversion of the Fe(II)-based spin crossover film is associated with a transition from a space charge-limited current (SCLC) transport mechanism with shallow traps to a SCLC mechanism characterized by the presence of an exponential distribution of traps concomitant with the spin transition temperature.
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Affiliation(s)
- Giuseppe Cucinotta
- Department of Chemistry
“U. Schiff” and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, FI 50019, Italy
| | - Lorenzo Poggini
- Department of Chemistry
“U. Schiff” and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, FI 50019, Italy
- CNRS, University of Bordeaux, ICMCB, UMR 5026, Pessac 33600, France
| | - Niccolò Giaconi
- Department of Chemistry
“U. Schiff” and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, FI 50019, Italy
| | - Alberto Cini
- Department of Physics and Astronomy and
INSTM Research Unit, University of Florence, Via Sansone 1, Sesto Fiorentino, FI 50019, Italy
| | - Mathieu Gonidec
- CNRS, University of Bordeaux, ICMCB, UMR 5026, Pessac 33600, France
| | - Matteo Atzori
- Department of Chemistry
“U. Schiff” and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, FI 50019, Italy
| | - Enrico Berretti
- Institute for Chemistry of OrganoMetallic
Compounds (ICCOM-CNR), Via Madonna del Piano, Sesto Fiorentino, FI 50019, Italy
| | - Alessandro Lavacchi
- Institute for Chemistry of OrganoMetallic
Compounds (ICCOM-CNR), Via Madonna del Piano, Sesto Fiorentino, FI 50019, Italy
| | - Maria Fittipaldi
- Department of Physics and Astronomy and
INSTM Research Unit, University of Florence, Via Sansone 1, Sesto Fiorentino, FI 50019, Italy
| | | | - Rudolf Rüffer
- ESRF-The European Synchrotron, Avenue des Martyrs 71, Grenoble 38000, France
| | - Patrick Rosa
- CNRS, University of Bordeaux, ICMCB, UMR 5026, Pessac 33600, France
| | - Matteo Mannini
- Department of Chemistry
“U. Schiff” and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, FI 50019, Italy
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14
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Stemer DM, Abendroth JM, Cheung KM, Ye M, El Hadri MS, Fullerton EE, Weiss PS. Differential Charging in Photoemission from Mercurated DNA Monolayers on Ferromagnetic Films. Nano Lett 2020; 20:1218-1225. [PMID: 31960675 PMCID: PMC7058983 DOI: 10.1021/acs.nanolett.9b04622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Spin-dependent and enantioselective electron-molecule scattering occurs in photoelectron transmission through chiral molecular films. This spin selectivity leads to electron spin filtering by molecular helices, with increasing magnitude concomitant with increasing numbers of helical turns. Using ultraviolet photoelectron spectroscopy, we measured spin-selective surface charging accompanying photoemission from ferromagnetic substrates functionalized with monolayers of mercurated DNA hairpins that constitute only one helical turn. Mercury ions bind specifically at thymine-thymine mismatches within self-hybridized single-stranded DNA, enabling precise control over the number and position of Hg2+ along the helical axis. Differential charging of the organic layers, manifested as substrate-magnetization-dependent photoionization energies, was observed for DNA hairpins containing Hg2+; no differences were measured for hairpin monolayers in the absence of Hg2+. Inversion of the DNA helical secondary structure at increased metal loading led to complementary inversion in spin selectivity. We attribute these results to increased scattering probabilities from relativistic enhancement of spin-orbit interactions in mercurated DNA.
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Affiliation(s)
- Dominik M. Stemer
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science & Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - John M. Abendroth
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Kevin M. Cheung
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Matthew Ye
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Mohammed S. El Hadri
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, United States
| | - Eric E. Fullerton
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, United States
| | - Paul S. Weiss
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science & Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Corresponding author: (PSW)
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15
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Bairagi K, Romero DG, Calavalle F, Catalano S, Zuccatti E, Llopis R, Casanova F, Hueso LE. Room-Temperature Operation of a p-Type Molecular Spin Photovoltaic Device on a Transparent Substrate. Adv Mater 2020; 32:e1906908. [PMID: 31944432 DOI: 10.1002/adma.201906908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/19/2019] [Indexed: 06/10/2023]
Abstract
The coupling of diverse degrees of freedom opens the door to physical effects that go beyond each of them individually, making multifunctionality a much sought-after attribute for high-performance devices. Here, the multifunctional operation of a single-layer p-type organic device, displaying both spin transport and photovoltaic effect at the room temperature on a transparent substrate, is shown. The generated photovoltage is almost three times larger than the applied bias to the device which facilitates the modulation of the magnetic response of the device with both bias and light. The device shows an increase in power conversion efficiency under magnetic field, an ability to invert the current with magnetic field and under certain conditions it can act as a spin photodetector with zero power consumption in the standby mode. The room-temperature exploitation of the interplay among light, bias, and magnetic field in the single device with a p-type molecule opens a way toward the development of efficient high-performance spin photovoltaic cells.
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Affiliation(s)
- Kaushik Bairagi
- CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country, Spain
| | | | | | - Sara Catalano
- CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country, Spain
| | | | - Roger Llopis
- CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Fèlix Casanova
- CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Basque Country, Spain
| | - Luis E Hueso
- CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Basque Country, Spain
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16
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Puhl S, Steenbock T, Herrmann C, Heck J. Controlling Through-Space and Through-Bond Exchange Pathways in Bis-Cobaltocenes for Molecular Spintronics. Angew Chem Int Ed Engl 2019; 59:2407-2413. [PMID: 31705778 PMCID: PMC7004085 DOI: 10.1002/anie.201911999] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/06/2019] [Indexed: 11/21/2022]
Abstract
Pinching molecules via chemical strain suggests intuitive consequences, such as compression at the pinched site and clothespin‐like opening of other parts of the structure. If this opening affects two spin centers, it should result in reduced communication between them. We show that for naphthalene‐bridged biscobaltocenes with competing through‐space and through‐bond pathways, the consequences of pinching are far less intuitive: despite the known dominance of through‐space interactions, the bridge plays a much larger role for exchange spin coupling than previously assumed. Based on a combination of chemical synthesis, structural, magnetic, and redox characterization, and a newly developed theoretical pathway analysis, we can suggest a comprehensive explanation for this non‐intuitive behavior. These results are of interest for molecular spintronics, as naphthalene‐linked cobaltocenes can form wires on surfaces for potential spin‐only information transfer.
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Affiliation(s)
- Sarah Puhl
- Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Torben Steenbock
- Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Carmen Herrmann
- Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Jürgen Heck
- Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
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17
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Studniarek M, Wäckerlin C, Singha A, Baltic R, Diller K, Donati F, Rusponi S, Brune H, Lan Y, Klyatskaya S, Ruben M, Seitsonen AP, Dreiser J. Understanding the Superior Stability of Single-Molecule Magnets on an Oxide Film. Adv Sci (Weinh) 2019; 6:1901736. [PMID: 31763154 PMCID: PMC6864999 DOI: 10.1002/advs.201901736] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/05/2019] [Indexed: 05/12/2023]
Abstract
The stability of magnetic information stored in surface adsorbed single-molecule magnets is of critical interest for applications in nanoscale data storage or quantum computing. The present study combines X-ray magnetic circular dichroism, density functional theory and magnetization dynamics calculations to gain deep insight into the substrate dependent relevant magnetization relaxation mechanisms. X-ray magnetic circular dichroism reveals the opening of a butterfly-shaped magnetic hysteresis of DyPc2 molecules on magnesium oxide and a closed loop on the bare silver substrate, while density functional theory shows that the molecules are only weakly adsorbed in both cases of magnesium oxide and silver. The enhanced magnetic stability of DyPc2 on the oxide film, in conjunction with previous experiments on the TbPc2 analogue, points to a general validity of the magnesium oxide induced stabilization effect. Magnetization dynamics calculations reveal that the enhanced magnetic stability of DyPc2 and TbPc2 on the oxide film is due to the suppression of two-phonon Raman relaxation processes. The results suggest that substrates with low phonon density of states are beneficial for the design of spintronics devices based on single-molecule magnets.
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Affiliation(s)
- Michał Studniarek
- Swiss Light SourcePaul Scherrer Institut (PSI)CH‐5232VilligenSwitzerland
| | - Christian Wäckerlin
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
- Institute of PhysicsThe Czech Academy of SciencesCukrovarnická 10CZ‐162 00Prague 6Czech Republic
| | - Aparajita Singha
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)03760SeoulRepublic of Korea
- Department of PhysicsEwha Womans University03760SeoulRepublic of Korea
| | - Romana Baltic
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
| | - Katharina Diller
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
| | - Fabio Donati
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)03760SeoulRepublic of Korea
- Department of PhysicsEwha Womans University03760SeoulRepublic of Korea
| | - Stefano Rusponi
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
| | - Harald Brune
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
| | - Yanhua Lan
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT)Hermann‐von‐Helmholtz‐Platz 1D‐76344Eggenstein‐LeopoldshafenGermany
| | - Svetlana Klyatskaya
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT)Hermann‐von‐Helmholtz‐Platz 1D‐76344Eggenstein‐LeopoldshafenGermany
| | - Mario Ruben
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT)Hermann‐von‐Helmholtz‐Platz 1D‐76344Eggenstein‐LeopoldshafenGermany
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS)Centre National de la Recherche Scientifique (CNRS)Université de Strasbourg23 rue du Loess, BP 43F‐67034Strasbourg Cedex 2France
| | - Ari Paavo Seitsonen
- Département de ChimieÉcole Normale SupérieureF‐75005ParisFrance
- Centre National de la Recherche Scientifique (CNRS)Paris Sciences et LettresSorbonne UniversitéF‐75005ParisFrance
| | - Jan Dreiser
- Swiss Light SourcePaul Scherrer Institut (PSI)CH‐5232VilligenSwitzerland
- Institute of Physics (IPHYS)École Polytechnique Fédérale de Lausanne (EPFL)Station 3CH‐1015LausanneSwitzerland
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18
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Guo L, Gu X, Zhu X, Sun X. Recent Advances in Molecular Spintronics: Multifunctional Spintronic Devices. Adv Mater 2019; 31:e1805355. [PMID: 30680807 DOI: 10.1002/adma.201805355] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/23/2018] [Indexed: 06/09/2023]
Abstract
The field of spintronics has triggered an enormous revolution in information storage since the first observation of giant magnetoresistance (GMR). Molecular semiconductors are characterized by having very long spin relaxation times up to milliseconds, and are thus widely considered to hold immense potential for spintronic applications. Along with the development of molecular spintronics, it is clear that the study of multipurpose spintronic devices has gradually grown into a new research and development direction. The abundant photoelectric properties of molecular semiconductors and the intriguing functionality of the spinterface, together with novel designs of device structures, have promoted the integration of multiple functions and different mechanisms into discrete spintronic devices. Here, according to the different relationships between the integrated mechanisms, multifunctional molecular spintronic devices containing parallel and interactive types are highlighted. This is followed by the introduction of pure-spin-current-type molecular spintronic devices that have already demonstrated great potential for multifunction exploration. Finally, the challenges and outlook that make this field young and energetic are outlined.
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Affiliation(s)
- Lidan Guo
- Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, Beijing, 102249, P. R. China
| | - Xianrong Gu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xiangwei Zhu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xiangnan Sun
- Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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19
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Isshiki H, Kondou K, Takizawa S, Shimose K, Kawabe T, Minamitani E, Yamaguchi N, Ishii F, Shiotari A, Sugimoto Y, Miwa S, Otani Y. Realization of Spin-dependent Functionality by Covering a Metal Surface with a Single Layer of Molecules. Nano Lett 2019; 19:7119-7123. [PMID: 31429575 DOI: 10.1021/acs.nanolett.9b02619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An interface of molecule and metal has attracted much attention in the research field of nanoelectronics because of their high degree of design freedom. Here, we demonstrate an efficient spin-to-charge current conversion at the metal surface covered by a single layer of molecules. Spin currents are injected into an interface between metal (Cu) and lead(II) phthalocyanine by means of the spin pumping method. An observed voltage signal is caused by the inverse Edelstein effect, i.e., spin-to-charge current conversion at the interface. The conversion coefficient, inverse Edelstein length, is estimated to be 0.40 ± 0.06 nm, comparable with the largest Rashba spin splitting of interfaces with heavy metals. Interestingly, the Edelstein length strongly depends on the thickness of the molecule and takes a maximum value when a single layer of molecules is formed on the Cu surface. Comparative analysis between scanning probe microscopy and first-principles calculations reveal that the formation of interface state with Rashba spin splitting causes the inverse Edelstein effect, whose magnitude is sensitive to the adsorption configuration of the molecules.
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Affiliation(s)
- H Isshiki
- Institute for Solid State Physics , The University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - K Kondou
- Institute for Solid State Physics , The University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
- RIKEN Center for Emergent Matter Science (CEMS) , Wako , Saitama 351-0198 , Japan
| | - S Takizawa
- Institute for Solid State Physics , The University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - K Shimose
- Graduate School of Engineering Science , Osaka University , Toyonaka , Osaka 560-8531 , Japan
| | - T Kawabe
- Graduate School of Engineering Science , Osaka University , Toyonaka , Osaka 560-8531 , Japan
| | - E Minamitani
- Graduate School of Engineering , The University of Tokyo , Bunkyo , Tokyo 113-8656 , Japan
| | - N Yamaguchi
- Graduate School of Natural Science and Technology , Kanazawa University , Kanazawa , Ishikawa 920-1192 , Japan
| | - F Ishii
- Nanomaterials Research Institute , Kanazawa University , Kanazawa , Ishikawa 920-1192 , Japan
| | - A Shiotari
- Department of Advanced Materials Science , The University of Tokyo , Kashiwa , Chiba 277-8561 , Japan
| | - Y Sugimoto
- Department of Advanced Materials Science , The University of Tokyo , Kashiwa , Chiba 277-8561 , Japan
| | - S Miwa
- Institute for Solid State Physics , The University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
- Graduate School of Engineering Science , Osaka University , Toyonaka , Osaka 560-8531 , Japan
| | - Y Otani
- Institute for Solid State Physics , The University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
- RIKEN Center for Emergent Matter Science (CEMS) , Wako , Saitama 351-0198 , Japan
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20
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Xu K, Yang T, Feng Y, Ruan X, Liu Z, Liang G, Wang X. Endohedral Fullerene Fe@C 28 Adsorbed on Au(111) Surface as a High-Efficiency Spin Filter: A Theoretical Study. Nanomaterials (Basel) 2019; 9:E1068. [PMID: 31349620 DOI: 10.3390/nano9081068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
We present a theoretical study on the adsorption and spin transport properties of magnetic Fe@C28 using Ab initio calculations based on spin density functional theory and non-equilibrium Green’s function techniques. Fe@C28 tends to adsorb on the bridge sites in the manner of C–C bonds, and the spin-resolved transmission spectra of Fe@C28 molecular junctions exhibit robust transport spin polarization (TSP). Under small bias voltage, the transport properties of Fe@C28 are mainly determined by the spin-down channel and exhibit a large spin polarization. When compressing the right electrode, the TSP is decreased, but high spin filter efficiency (SFE) is still maintained. These theoretical results indicate that Fe@C28 with a large magnetic moment has potential applications in molecular spintronics.
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21
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Torres-Cavanillas R, Sanchis-Gual R, Dugay J, Coronado-Puchau M, Giménez-Marqués M, Coronado E. Design of Bistable Gold@Spin-Crossover Core-Shell Nanoparticles Showing Large Electrical Responses for the Spin Switching. Adv Mater 2019; 31:e1900039. [PMID: 30998264 DOI: 10.1002/adma.201900039] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/20/2019] [Indexed: 06/09/2023]
Abstract
A simple chemical protocol to prepare core-shell gold@spin-crossover (Au@SCO) nanoparticles (NPs) based on the 1D spin-crossover [Fe(Htrz)2 (trz)](BF4 ) coordination polymer is reported. The synthesis relies on a two-step approach consisting of a partial surface ligand substitution of the citrate-stabilized Au NPs followed by the controlled growth of a very thin layer of the SCO polymer. As a result, colloidally stable core@shell spherical NPs with a Au core of ca. 12 nm and a thin SCO shell 4 nm thick, are obtained, exhibiting a narrow distribution in sizes. Differential scanning calorimetry proves that a cooperative spin transition in the range 340-360 K is maintained in these Au@SCO NPs, in full agreement with the values reported for pristine 4 nm SCO NPs. Temperature-dependent charge-transport measurements of an electrical device based on assemblies of these Au@SCO NPs also support this spin transition. Thus, a large change in conductance upon spin state switching, as compared with other memory devices based on the pristine SCO NPs, is detected. This results in a large improvement in the sensitivity of the device to the spin transition, with values for the ON/OFF ratio which are an order of magnitude better than the best ones obtained in previous SCO devices.
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Affiliation(s)
- Ramón Torres-Cavanillas
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Roger Sanchis-Gual
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Julien Dugay
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Marc Coronado-Puchau
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Mónica Giménez-Marqués
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán 2, Paterna, 46980, Spain
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22
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Abstract
Because of the considerable advantages of functional molecules as well as supramolecules, such as the low cost, light weight, flexibility, and large area preparation via the solution method, molecular electronics has grown into an active and rapidly developing research field over the past few decades. Beyond those well-known advantages, a very long spin relaxation time of π-conjugated molecules, due to the weak spin-orbit coupling, facilitates a pioneering but fast-growing research field, known as molecular spintronics. Recently, a series of sustained progresses have been achieved with various π-conjugated molecular matrixes where spin transport is undoubtedly an important point for the spin physical process and multifunctional applications. Currently, most studies on spin transport are carried out with a molecule-based spin valve, which shows a typical geometry with a thin-film molecular layer sandwiched between two ferromagnetic electrodes. In such a device, the spin transport process has been demonstrated to have a close correlation with spin relaxation time and charge carrier mobility of π-conjugated molecules. In this review, the recent advances of spin transport in these two aspects have been systematically summarized. Particularly, spin transport in π-conjugated molecular materials, considered as promising for spintronics development, have also been highlighted, including molecular single crystal, cocrystal, solid solution as well as other highly ordered supramolecular structures.
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Affiliation(s)
- Lidan Guo
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, CAS (Chinese Academy of Sciences) Center for Excellence in Nanoscience, Beijing, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China.,Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, Beijing, China
| | - Yang Qin
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, CAS (Chinese Academy of Sciences) Center for Excellence in Nanoscience, Beijing, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xianrong Gu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, CAS (Chinese Academy of Sciences) Center for Excellence in Nanoscience, Beijing, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xiangwei Zhu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, CAS (Chinese Academy of Sciences) Center for Excellence in Nanoscience, Beijing, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Qiong Zhou
- Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum Beijing, Beijing, China
| | - Xiangnan Sun
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, CAS (Chinese Academy of Sciences) Center for Excellence in Nanoscience, Beijing, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
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23
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Wernsdorfer W, Ruben M. Synthetic Hilbert Space Engineering of Molecular Qudits: Isotopologue Chemistry. Adv Mater 2019; 31:e1806687. [PMID: 30803060 DOI: 10.1002/adma.201806687] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/09/2019] [Indexed: 06/09/2023]
Abstract
One of the most ambitious technological goals is the development of devices working under the laws of quantum mechanics. Among others, an important challenge to be resolved on the way to such breakthrough technology concerns the scalability of the available Hilbert space. Recently, proof-of-principle experiments were reported, in which the implementation of quantum algorithms (the Grover's search algorithm, iSWAP-gate, etc.) in a single-molecule nuclear spin qudit (with d = 4) known as 159 TbPc2 was described, where the nuclear spins of lanthanides are used as a quantum register to execute simple quantum algorithms. In this progress report, the goal of linear and exponential up-scalability of the available Hilbert space expressed by the qudit-dimension "d" is addressed by synthesizing lanthanide metal complexes as quantum computing hardware. The synthesis of multinuclear large-Hilbert-space complexes has to be carried out under strict control of the nuclear spin degree of freedom leading to isotopologues, whereby electronic coupling between several nuclear spin units will exponentially extend the Hilbert space available for quantum information processing. Thus, improved multilevel spin qudits can be achieved that exhibit an exponentially scalable Hilbert space to enable high-performance quantum computing and information storage.
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Affiliation(s)
- Wolfgang Wernsdorfer
- Institute of Physics (PHI), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1, D-76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT) and Institute of Quantum Materials and Technology (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344, Eggenstein-Leopoldshafen, Germany
| | - Mario Ruben
- Institute of Nanotechnology (INT) and Institute of Quantum Materials and Technology (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344, Eggenstein-Leopoldshafen, Germany
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Université de Strasbourg, 23 rue du Loess, BP 43, F-67034, Strasbourg Cedex 2, France
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24
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Abendroth JM, Stemer DM, Bloom BP, Roy P, Naaman R, Waldeck DH, Weiss PS, Mondal PC. Spin Selectivity in Photoinduced Charge-Transfer Mediated by Chiral Molecules. ACS Nano 2019; 13:4928-4946. [PMID: 31016968 DOI: 10.1021/acsnano.9b01876] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Optical control and readout of electron spin and spin currents in thin films and nanostructures have remained attractive yet challenging goals for emerging technologies designed for applications in information processing and storage. Recent advances in room-temperature spin polarization using nanometric chiral molecular assemblies suggest that chemically modified surfaces or interfaces can be used for optical spin conversion by exploiting photoinduced charge separation and injection from well-coupled organic chromophores or quantum dots. Using light to drive photoexcited charge-transfer processes mediated by molecules with central or helical chirality enables indirect measurements of spin polarization attributed to the chiral-induced spin selectivity effect and of the efficiency of spin-dependent electron transfer relative to competitive relaxation pathways. Herein, we highlight recent approaches used to detect and to analyze spin selectivity in photoinduced charge transfer including spin-transfer torque for local magnetization, nanoscale charge separation and polarization, and soft ferromagnetic substrate magnetization- and chirality-dependent photoluminescence. Building on these methods through systematic investigation of molecular and environmental parameters that influence spin filtering should elucidate means to manipulate electron spins and photoexcited states for room-temperature optoelectronic and photospintronic applications.
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Affiliation(s)
- John M Abendroth
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Dominik M Stemer
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Materials Science and Engineering , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Brian P Bloom
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Partha Roy
- Department of Chemistry , Central University of Rajasthan , Kishangarh 305817 Ajmer , India
| | - Ron Naaman
- Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - David H Waldeck
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Paul S Weiss
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Materials Science and Engineering , University of California, Los Angeles , Los Angeles , California 90095 , United States
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25
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Prieto-Ruiz JP, Miralles SG, Prima-García H, López-Muñoz A, Riminucci A, Graziosi P, Aeschlimann M, Cinchetti M, Dediu VA, Coronado E. Enhancing Light Emission in Interface Engineered Spin-OLEDs through Spin-Polarized Injection at High Voltages. Adv Mater 2019; 31:e1806817. [PMID: 30645012 DOI: 10.1002/adma.201806817] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 12/03/2018] [Indexed: 06/09/2023]
Abstract
The quest for a spin-polarized organic light-emitting diode (spin-OLED) is a common goal in the emerging fields of molecular electronics and spintronics. In this device, two ferromagnetic (FM) electrodes are used to enhance the electroluminescence intensity of the OLED through a magnetic control of the spin polarization of the injected carriers. The major difficulty is that the driving voltage of an OLED device exceeds a few volts, while spin injection in organic materials is only efficient at low voltages. The fabrication of a spin-OLED that uses a conjugated polymer as bipolar spin collector layer and ferromagnetic electrodes is reported here. Through a careful engineering of the organic/inorganic interfaces, it is succeeded in obtaining a light-emitting device showing spin-valve effects at high voltages (up to 14 V). This allows the detection of a magneto-electroluminescence (MEL) enhancement on the order of a 2.4% at 9 V for the antiparallel (AP) configuration of the magnetic electrodes. This observation provides evidence for the long-standing fundamental issue of injecting spins from magnetic electrodes into the frontier levels of a molecular semiconductor. The finding opens the way for the design of multifunctional devices coupling the light and the spin degrees of freedom.
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Affiliation(s)
- Juan Pablo Prieto-Ruiz
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia. Catedrático José Beltrán 2, 46890, Paterna, Spain
| | - Sara Gómez Miralles
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia. Catedrático José Beltrán 2, 46890, Paterna, Spain
| | - Helena Prima-García
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia. Catedrático José Beltrán 2, 46890, Paterna, Spain
| | - Angel López-Muñoz
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia. Catedrático José Beltrán 2, 46890, Paterna, Spain
| | - Alberto Riminucci
- Instituto per lo Studio dei Materiali Nanostrutturati ISMN - CNR, Via Gobetti, 101, Bologna, 40129, Italy
| | - Patrizio Graziosi
- Instituto per lo Studio dei Materiali Nanostrutturati ISMN - CNR, Via Gobetti, 101, Bologna, 40129, Italy
| | - Martin Aeschlimann
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger-Strasse 46, 67663, Kaiserslautern, Germany
| | - Mirko Cinchetti
- Experimentelle Physik VI, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - Valentin Alek Dediu
- Instituto per lo Studio dei Materiali Nanostrutturati ISMN - CNR, Via Gobetti, 101, Bologna, 40129, Italy
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia. Catedrático José Beltrán 2, 46890, Paterna, Spain
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26
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Riminucci A, Yu ZG, Prezioso M, Cecchini R, Bergenti I, Graziosi P, Dediu VA. Controlling Magnetoresistance by Oxygen Impurities in Mq3-Based Molecular Spin Valves. ACS Appl Mater Interfaces 2019; 11:8319-8326. [PMID: 30720264 DOI: 10.1021/acsami.8b20423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The understanding of magnetoresistance (MR) in organic spin valves (OSVs) based on molecular semiconductors is still incomplete after its demonstration more than a decade ago. Although carrier concentration may play an essential role in spin transport in these devices, direct experimental evidence of its importance is lacking. We probed the role of the charge carrier concentration by studying the interplay between MR and multilevel resistive switching in OSVs. The present work demonstrates that all salient features of these devices, particularly the intimate correlation between MR and resistance, can be accounted for by the impurity band model, based on oxygen migration. Finally, we highlight the critical importance of the carrier concentration in determining spin transport and MR in OSVs and the role of interface-mediated oxygen migration in controlling the OSV response.
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Affiliation(s)
| | - Zhi-Gang Yu
- ISP/Applied Sciences Laboratory , Washington State University , Spokane , Washington 99210 , United States
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27
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Al-Bustami H, Koplovitz G, Primc D, Yochelis S, Capua E, Porath D, Naaman R, Paltiel Y. Single Nanoparticle Magnetic Spin Memristor. Small 2018; 14:e1801249. [PMID: 29952065 DOI: 10.1002/smll.201801249] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 05/09/2018] [Indexed: 05/21/2023]
Abstract
There is an increasing demand for the development of a simple Si-based universal memory device at the nanoscale that operates at high frequencies. Spin-electronics (spintronics) can, in principle, increase the efficiency of devices and allow them to operate at high frequencies. A primary challenge for reducing the dimensions of spintronic devices is the requirement for high spin currents. To overcome this problem, a new approach is presented that uses helical chiral molecules exhibiting spin-selective electron transport, which is called the chiral-induced spin selectivity (CISS) effect. Using the CISS effect, the active memory device is miniaturized for the first time from the micrometer scale to 30 nm in size, and this device presents memristor-like nonlinear logic operation at low voltages under ambient conditions and room temperature. A single nanoparticle, along with Au contacts and chiral molecules, is sufficient to function as a memory device. A single ferromagnetic nanoplatelet is used as a fixed hard magnet combined with Au contacts in which the gold contacts act as soft magnets due to the adsorbed chiral molecules.
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Affiliation(s)
- Hammam Al-Bustami
- Applied Physics, Hebrew University of Jerusalem, Edmond J Safra Campus, Jerusalem, 919041, Israel
| | - Guy Koplovitz
- Applied Physics, Hebrew University of Jerusalem, Edmond J Safra Campus, Jerusalem, 919041, Israel
| | - Darinka Primc
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Tan Hall 373A, Berkeley, CA, 94720, USA
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, 8093, Switzerland
| | - Shira Yochelis
- Applied Physics, Hebrew University of Jerusalem, Edmond J Safra Campus, Jerusalem, 919041, Israel
| | - Eyal Capua
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Danny Porath
- Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Ron Naaman
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Yossi Paltiel
- Applied Physics, Hebrew University of Jerusalem, Edmond J Safra Campus, Jerusalem, 919041, Israel
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28
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Steenbock T, Herrmann C. Toward an automated analysis of exchange pathways in spin-coupled systems. J Comput Chem 2018; 39:81-92. [PMID: 29044625 DOI: 10.1002/jcc.25081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Accepted: 09/24/2017] [Indexed: 01/25/2023]
Abstract
Understanding (super-)exchange coupling between local spins is an important task in theoretical chemistry and solid-state physics. We show that a Green's-function approach introduced earlier (Liechtenstein et al., J. Phys. F 1984, 14, L125; Steenbock et al., J. Chem. Theory Comput. 2015, 11, 5651) can be used for analyzing exchange coupling pathways in an automated fashion rather than by visual inspection of molecular orbitals. We demonstrate the capabilities of this approach by comparing it to previously published pathway analyses for hydroxy-bridged dinuclear copper complexes and an oxo-bridged dinuclear manganese complex, and employ it for discriminating between through-space and through-bond pathways in a naphthalene-bridged bisnickelocene complex. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Torben Steenbock
- Institute of Inorganic and Applied Chemistry, Chemistry Department, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg, 20146, Germany
| | - Carmen Herrmann
- Institute of Inorganic and Applied Chemistry, Chemistry Department, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg, 20146, Germany
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29
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Affiliation(s)
- Georgeta Salvan
- Physics Department, Semiconductor Physics, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Dietrich R T Zahn
- Physics Department, Semiconductor Physics, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
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30
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Sierda E, Abadia M, Brede J, Elsebach M, Bugenhagen B, Prosenc MH, Bazarnik M, Wiesendanger R. On-Surface Oligomerization of Self-Terminating Molecular Chains for the Design of Spintronic Devices. ACS Nano 2017; 11:9200-9206. [PMID: 28813591 DOI: 10.1021/acsnano.7b04194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molecular spintronics is currently attracting a lot of attention due to its great advantages over traditional electronics. A variety of self-assembled molecule-based devices are under development, but studies regarding the reliability of the growth process remain rare. Here, we present a method to control the length of molecular spintronic chains and to make their terminations chemically inert, thereby suppressing uncontrolled coupling to surface defects. The temperature evolution of chain formation was followed by X-ray photoelectron spectroscopy to determine optimal growth conditions. The final structures of the chains were then studied, using scanning tunneling microscopy, as a function of oligomerization conditions. We find that short chains are readily synthesized with high yields and that long chains, even exceeding 70mers, can be realized under optimized growth parameters, albeit with reduced yields.
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Affiliation(s)
- Emil Sierda
- Department of Physics, University of Hamburg , Jungiusstrasse 11, D-20355 Hamburg, Germany
- Institute of Physics, Poznan University of Technology , Piotrowo 3, 60-965 Poznań, Poland
| | - Mikel Abadia
- Centro de Física de Materiales (Consejo Superior de Investigaciones Científicas (CSIC) , Universidad del País Vasco (UPV)-Euskal Herriko Unibertsitatea (EHU)-Materials Physics Center (MPC), Paseo Manuel Lardizabal 5, 20018 San Sebastián, Spain
- Donostia International Physics Center (DIPC) , Paseo Manuel Lardizabal 4, 20018 San Sebastián, Spain
| | - Jens Brede
- Centro de Física de Materiales (Consejo Superior de Investigaciones Científicas (CSIC) , Universidad del País Vasco (UPV)-Euskal Herriko Unibertsitatea (EHU)-Materials Physics Center (MPC), Paseo Manuel Lardizabal 5, 20018 San Sebastián, Spain
- Donostia International Physics Center (DIPC) , Paseo Manuel Lardizabal 4, 20018 San Sebastián, Spain
| | - Micha Elsebach
- Department of Physics, University of Hamburg , Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - Bernhard Bugenhagen
- Institute of Inorganic and Applied Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Marc Heinrich Prosenc
- Institute of Inorganic and Applied Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
- Department of Chemistry, Technical University Kaiserslautern , Erwin-Schrödinger-Str. 52, D-67663 Kaiserslautern, Germany
| | - Maciej Bazarnik
- Department of Physics, University of Hamburg , Jungiusstrasse 11, D-20355 Hamburg, Germany
- Institute of Physics, Poznan University of Technology , Piotrowo 3, 60-965 Poznań, Poland
| | - Roland Wiesendanger
- Department of Physics, University of Hamburg , Jungiusstrasse 11, D-20355 Hamburg, Germany
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31
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Robaschik P, Ma Y, Din S, Heutz S. Formation of ferromagnetic molecular thin films from blends by annealing. Beilstein J Nanotechnol 2017; 8:1469-1475. [PMID: 28900600 PMCID: PMC5530637 DOI: 10.3762/bjnano.8.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
We report on a new approach for the fabrication of ferromagnetic molecular thin films. Co-evaporated films of manganese phthalocyanine (MnPc) and tetracyanoquinodimethane (TCNQ) have been produced by organic molecular beam deposition (OMBD) on rigid (glass, silicon) and flexible (Kapton) substrates kept at room temperature. The MnPc:TCNQ films are found to be entirely amorphous due to the size mismatch of the molecules. However, by annealing while covering the samples highly crystalline MnPc films in the β-polymorph can be obtained at 60 °C lower than when starting with pure MnPc films. The resulting films exhibit substantial coercivity (13 mT) at 2 K and a Curie temperature of 11.5 K.
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Affiliation(s)
- Peter Robaschik
- Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Rd, London SW7 2AZ, United Kingdom
| | - Ye Ma
- Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Rd, London SW7 2AZ, United Kingdom
| | - Salahud Din
- Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Rd, London SW7 2AZ, United Kingdom
- Kurt J. Lesker Company, Sidney Little Rd, St Leonard’s on Sea TN38 9PU, United Kingdom
| | - Sandrine Heutz
- Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Rd, London SW7 2AZ, United Kingdom
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32
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Al Ma'Mari F, Rogers M, Alghamdi S, Moorsom T, Lee S, Prokscha T, Luetkens H, Valvidares M, Teobaldi G, Flokstra M, Stewart R, Gargiani P, Ali M, Burnell G, Hickey BJ, Cespedes O. Emergent magnetism at transition-metal-nanocarbon interfaces. Proc Natl Acad Sci U S A 2017; 114:5583-5588. [PMID: 28507160 PMCID: PMC5465901 DOI: 10.1073/pnas.1620216114] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Charge transfer at metallo-molecular interfaces may be used to design multifunctional hybrids with an emergent magnetization that may offer an eco-friendly and tunable alternative to conventional magnets and devices. Here, we investigate the origin of the magnetism arising at these interfaces by using different techniques to probe 3d and 5d metal films such as Sc, Mn, Cu, and Pt in contact with fullerenes and rf-sputtered carbon layers. These systems exhibit small anisotropy and coercivity together with a high Curie point. Low-energy muon spin spectroscopy in Cu and Sc-C60 multilayers show a quick spin depolarization and oscillations attributed to nonuniform local magnetic fields close to the metallo-carbon interface. The hybridization state of the carbon layers plays a crucial role, and we observe an increased magnetization as sp3 orbitals are annealed into sp2-π graphitic states in sputtered carbon/copper multilayers. X-ray magnetic circular dichroism (XMCD) measurements at the carbon K edge of C60 layers in contact with Sc films show spin polarization in the lowest unoccupied molecular orbital (LUMO) and higher π*-molecular levels, whereas the dichroism in the σ*-resonances is small or nonexistent. These results support the idea of an interaction mediated via charge transfer from the metal and dz-π hybridization. Thin-film carbon-based magnets may allow for the manipulation of spin ordering at metallic surfaces using electrooptical signals, with potential applications in computing, sensors, and other multifunctional magnetic devices.
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Affiliation(s)
- Fatma Al Ma'Mari
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
- Department of Physics, Sultan Qaboos University, 123 Muscat, Oman
| | - Matthew Rogers
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Shoug Alghamdi
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Timothy Moorsom
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Stephen Lee
- School of Physics and Astronomy, Scottish Universities Physics Alliance, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - Thomas Prokscha
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Hubertus Luetkens
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | | | - Gilberto Teobaldi
- Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
- Beijing Computational Science Research Centre, Beijing 100193 China
| | - Machiel Flokstra
- School of Physics and Astronomy, Scottish Universities Physics Alliance, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - Rhea Stewart
- School of Physics and Astronomy, Scottish Universities Physics Alliance, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | | | - Mannan Ali
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Gavin Burnell
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - B J Hickey
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom;
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Cardona-Serra S, Sanvito S. Influence of the dipolar interactions on the relative stability in spin crossover systems. J Comput Chem 2017; 38:224-227. [PMID: 27882575 DOI: 10.1002/jcc.24676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 12/30/2022]
Abstract
Molecules exhibiting a spin-crossover transition have been proposed for a number of applications such as molecular switches, spintronic tunable interfaces, and single molecule gates. Both the rational design of new spin-crossover systems and the improvement of the properties of the already existing ones require a theoretical understanding of the relative energy of the high (HS) and low spin state (LS) molecules in the solid-state. This has proved to be very challenging so far. Here, we shed some light on the importance of considering the symmetry and the geometry of the crystallographic cell to correctly evaluate the influence of the dipolar interactions on the relative energies of the molecular complex in both different spin states. Moreover, in the case of Fe(SCN)2 (phen)2 dipolar interactions are found to play an important role for the stabilization of the LS complex. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Stefano Sanvito
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
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Dugay J, Aarts M, Giménez-Marqués M, Kozlova T, Zandbergen HW, Coronado E, van der Zant HSJ. Phase Transitions in Spin-Crossover Thin Films Probed by Graphene Transport Measurements. Nano Lett 2017; 17:186-193. [PMID: 28073272 DOI: 10.1021/acs.nanolett.6b03780] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Future multifunctional hybrid devices might combine switchable molecules and 2D material-based devices. Spin-crossover compounds are of particular interest in this context since they exhibit bistability and memory effects at room temperature while responding to numerous external stimuli. Atomically thin 2D materials such as graphene attract a lot of attention for their fascinating electrical, optical, and mechanical properties, but also for their reliability for room-temperature operations. Here, we demonstrate that thermally induced spin-state switching of spin-crossover nanoparticle thin films can be monitored through the electrical transport properties of graphene lying underneath the films. Model calculations indicate that the charge carrier scattering mechanism in graphene is sensitive to the spin-state dependence of the relative dielectric constants of the spin-crossover nanoparticles. This graphene sensor approach can be applied to a wide class of (molecular) systems with tunable electronic polarizabilities.
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Affiliation(s)
- J Dugay
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - M Aarts
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - M Giménez-Marqués
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia , c/Catedrático José Beltrán, 2, 46980 Paterna, Spain
- Institut Lavoisier, UMR CNRS 8180, Université de Versailles Saint-Quentin-en-Yvelines , 45 Av. des Etats-Unis, 78035 Versailles cedex, France
| | - T Kozlova
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - H W Zandbergen
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - E Coronado
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia , c/Catedrático José Beltrán, 2, 46980 Paterna, Spain
| | - H S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
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Holovchenko A, Dugay J, Giménez-Marqués M, Torres-Cavanillas R, Coronado E, van der Zant HSJ. Near Room-Temperature Memory Devices Based on Hybrid Spin-Crossover@SiO2 Nanoparticles Coupled to Single-Layer Graphene Nanoelectrodes. Adv Mater 2016; 28:7228-7233. [PMID: 27184546 DOI: 10.1002/adma.201600890] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/18/2016] [Indexed: 06/05/2023]
Abstract
The charge transport properties of SCO [Fe(Htrz)2 (trz)](BF4 ) NPs covered with a silica shell placed in between single-layer graphene electrodes are reported. A reproducible thermal hysteresis loop in the conductance above room-temperature is evidenced. This bistability combined with the versatility of graphene represents a promising scenario for a variety of technological applications but also for future sophisticated fundamental studies.
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Affiliation(s)
- Anastasia Holovchenko
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands
| | - Julien Dugay
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands
| | - Mónica Giménez-Marqués
- Instituto de Ciencia Molecular, Unversidad de Valencia, Catedrático José Beltrán 2, 46980, Paterna, Spain
| | - Ramón Torres-Cavanillas
- Instituto de Ciencia Molecular, Unversidad de Valencia, Catedrático José Beltrán 2, 46980, Paterna, Spain
| | - Eugenio Coronado
- Instituto de Ciencia Molecular, Unversidad de Valencia, Catedrático José Beltrán 2, 46980, Paterna, Spain
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands
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36
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Frisenda R, Harzmann GD, Celis Gil JA, Thijssen JM, Mayor M, van der Zant HSJ. Stretching-Induced Conductance Increase in a Spin-Crossover Molecule. Nano Lett 2016; 16:4733-7. [PMID: 27088578 DOI: 10.1021/acs.nanolett.5b04899] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We investigate transport through mechanically triggered single-molecule switches that are based on the coordination sphere-dependent spin state of Fe(II)-species. In these molecules, in certain junction configurations the relative arrangement of two terpyridine ligands within homoleptic Fe(II)-complexes can be mechanically controlled. Mechanical pulling may thus distort the Fe(II) coordination sphere and eventually modify their spin state. Using the movable nanoelectrodes in a mechanically controlled break-junction at low temperature, current-voltage measurements at cryogenic temperatures support the hypothesized switching mechanism based on the spin-crossover behavior. A large fraction of molecular junctions formed with the spin-crossover-active Fe(II)-complex displays a conductance increase for increasing electrode separation and this increase can reach 1-2 orders of magnitude. Theoretical calculations predict a stretching-induced spin transition in the Fe(II)-complex and a larger transmission for the high-spin configuration.
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Affiliation(s)
- Riccardo Frisenda
- Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands
| | | | - Jose A Celis Gil
- Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands
| | - Joseph M Thijssen
- Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands
| | - Marcel Mayor
- University of Base l, 4056 Basel, Switzerland
- Karlsruhe Institute of Technology (KIT) , P.O. Box 3640, 76021 Karlsruhe, Germany
- Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University (SYSU) , Gunagzhou, China
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands
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37
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Gruber M, Ibrahim F, Boukari S, Joly L, Da Costa V, Studniarek M, Peter M, Isshiki H, Jabbar H, Davesne V, Arabski J, Otero E, Choueikani F, Chen K, Ohresser P, Wulfhekel W, Scheurer F, Beaurepaire E, Alouani M, Weber W, Bowen M. Spin-Dependent Hybridization between Molecule and Metal at Room Temperature through Interlayer Exchange Coupling. Nano Lett 2015; 15:7921-7926. [PMID: 26575946 DOI: 10.1021/acs.nanolett.5b02961] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We experimentally and theoretically show that the magnetic coupling at room temperature between paramagnetic Mn within manganese phthalocyanine molecules and a Co layer persists when separated by a Cu spacer. The molecule's magnetization amplitude and direction can be tuned by varying the Cu-spacer thickness and evolves according to an interlayer exchange coupling mechanism. Ab initio calculations predict a highly spin-polarized density of states at the Fermi level of this metal-molecule interface, thereby strengthening prospective spintronics applications.
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Affiliation(s)
- Manuel Gruber
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Fatima Ibrahim
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Samy Boukari
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Loïc Joly
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Victor Da Costa
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Michał Studniarek
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
- Synchrotron SOLEIL , L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Moritz Peter
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Hironari Isshiki
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Hashim Jabbar
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Vincent Davesne
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Jacek Arabski
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Edwige Otero
- Synchrotron SOLEIL , L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Fadi Choueikani
- Synchrotron SOLEIL , L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Kai Chen
- Synchrotron SOLEIL , L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Philippe Ohresser
- Synchrotron SOLEIL , L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Wulf Wulfhekel
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
- Institute of Nanotechnology, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
| | - Fabrice Scheurer
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Eric Beaurepaire
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Mebarek Alouani
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Wolfgang Weber
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Martin Bowen
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
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Abstract
Achieving highly spin-polarized electric currents in atomic-scale junctions is of great importance in the field of nanoelectronics and spintronics. Based on robust symmetry considerations, we propose a mechanism to block completely one of spin conduction channels for a broad class of atomic and molecular junctions bridging two ferromagnetic electrodes. This particular behavior is due to the wave function orthogonality between spin up s-like states in ferromagnetic electrode and available π channels in the junction. As a consequence, the system would ideally yield 100% spin-polarized current, with a junction acting thus as a "half-metallic" conductor. Using ab initio electron transport calculations, we demonstrate this principle on two examples: (i) a short carbon chain and (ii) a π-conjugated molecule (polythiophene) connected either to model semi-infinite Ni wires or to realistic Ni(111) electrodes. It is also predicted that such atomic-scale junctions should lead to very high (ideally, infinite) magneto-resistance ratios since the electric current gets fully blocked if two electrodes have antiparallel magnetic alignment.
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Affiliation(s)
- Alexander Smogunov
- Service de Physique de l'Etat Condensé DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- Service de Physique de l'Etat Condensé DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
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39
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Dugay J, Giménez-Marqués M, Kozlova T, Zandbergen HW, Coronado E, van der Zant HSJ. Spin switching in electronic devices based on 2D assemblies of spin-crossover nanoparticles. Adv Mater 2015; 27:1288-1293. [PMID: 25556348 DOI: 10.1002/adma.201404441] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/06/2014] [Indexed: 06/04/2023]
Abstract
Two-dimensional assemblies of triazole-based spin-crossover nanoparticles (SCO NPs) presenting different morphologies are prepared and electrically characterized. The thermal hysteresis loop in the electrical conductance near room temperature correlates with the NP morphologies and their 2D organization. The unprecedentedly large difference - up to two orders of magnitude - in the electrical conductance of the two spin states is of interest for applications.
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Affiliation(s)
- Julien Dugay
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628, CJ, Delft, The Netherlands
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40
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Candini A, Richter N, Convertino D, Coletti C, Balestro F, Wernsdorfer W, Kläui M, Affronte M. Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum. Beilstein J Nanotechnol 2015; 6:711-9. [PMID: 25821711 PMCID: PMC4362043 DOI: 10.3762/bjnano.6.72] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 02/09/2015] [Indexed: 05/07/2023]
Abstract
Graphene-based electrodes are very promising for molecular electronics and spintronics. Here we report a systematic characterization of the electroburning (EB) process, leading to the formation of nanometer-spaced gaps, on different types of few-layer graphene (namely mechanically exfoliated graphene on SiO2, graphene epitaxially grown on the C-face of SiC and turbostratic graphene discs deposited on SiO2) under air and vacuum conditions. The EB process is found to depend on both the graphene type and on the ambient conditions. For the mechanically exfoliated graphene, performing EB under vacuum leads to a higher yield of nanometer-gap formation than working in air. Conversely, for graphene on SiC the EB process is not successful under vacuum. Finally, the EB is possible with turbostratic graphene discs only after the creation of a constriction in the sample using lithographic patterning.
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Affiliation(s)
- Andrea Candini
- Centro S3, Istituto Nanoscienze – CNR, Via Campi 213/a, 41125 Modena, Italy
| | - Nils Richter
- Johannes Gutenberg Universität-Mainz, Institut für Physik, Staudinger Weg 7, 55128 Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz (MAINZ), Staudinger Weg 9, 55128 Mainz, Germany
| | - Domenica Convertino
- Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Camilla Coletti
- Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Franck Balestro
- Institut Néel, CNRS and Université Joseph Fourier, B.P. 166, 38042 Grenoble Cedex 09, France
- Institut Universitaire de France, 103 Boulevard Saint-Michel, 75005 Paris, France
| | - Wolfgang Wernsdorfer
- Institut Néel, CNRS and Université Joseph Fourier, B.P. 166, 38042 Grenoble Cedex 09, France
| | - Mathias Kläui
- Johannes Gutenberg Universität-Mainz, Institut für Physik, Staudinger Weg 7, 55128 Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz (MAINZ), Staudinger Weg 9, 55128 Mainz, Germany
| | - Marco Affronte
- Centro S3, Istituto Nanoscienze – CNR, Via Campi 213/a, 41125 Modena, Italy
- Dipartimento di scienze Fisiche Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
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41
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Hermanns CF, Tarafder K, Bernien M, Krüger A, Chang YM, Oppeneer PM, Kuch W. Magnetic coupling of porphyrin molecules through graphene. Adv Mater 2013; 25:3473-3477. [PMID: 23695989 DOI: 10.1002/adma.201205275] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/11/2013] [Indexed: 06/02/2023]
Abstract
X-ray magnetic circular dichroism (XMCD) measurements and density functional theory (DFT)+U calculations reveal an unexpected antiferromagnetic coupling between physisorbed paramagnetic Co-porphyrin molecules and a Ni surface, separated by a graphene layer. A positive magnetization at the Ni substrate atoms is mediated by graphene and induces a negative one at the Co site, despite only a very small overlap between macrocyclic π and graphene pz -orbitals.
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Affiliation(s)
- Christian F Hermanns
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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42
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Koleini M, Brandbyge M. Strong spin-filtering and spin-valve effects in a molecular V-C(60)-V contact. Beilstein J Nanotechnol 2012; 3:589-96. [PMID: 23019556 PMCID: PMC3458606 DOI: 10.3762/bjnano.3.69] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/20/2012] [Indexed: 06/01/2023]
Abstract
Motivated by the recent achievements in the manipulation of C(60) molecules in STM experiments, we study theoretically the structure and electronic properties of a C(60) molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111) surface using first-principles calculations. For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C(60), can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%). Moreover, we find a significant change in the conductance between parallel and anti-parallel spin polarizations in the junction (86%) which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems.
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Affiliation(s)
- Mohammad Koleini
- Hybrid Materials Interfaces Group, Faculty of Production Engineering and Bremen Center for Computational Materials Science, University of Bremen, 28359 Bremen, Germany
| | - Mads Brandbyge
- DTU Nanotech, Department of Micro and Nanotechnology, Technical University of Denmark, Ørsteds Plads, Building 345E, DK-2800 Kongens Lyngby, Denmark
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43
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Jiang H, Bai M, Wei P, Sun L, Shen Z, Hou S. Half-metallic properties of single-walled polymeric manganese phthalocyanine nanotubes. Sensors (Basel) 2012; 12:8438-46. [PMID: 23012498 PMCID: PMC3444056 DOI: 10.3390/s120708438] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/11/2012] [Accepted: 06/12/2012] [Indexed: 11/17/2022]
Abstract
We present a theoretical study of the electronic and magnetic properties of single-walled manganese phthalocyanine (MnPc) nanotubes which can be thought of as rolled-up ribbons of the two-dimensional (2D) polymeric MnPc sheet. Our density functional theory calculations show that all of the MnPc nanotubes investigated here are half-metals with 100% spin polarization around the Fermi level. Following the increase of the tube diameter, the number of spin-down energy bands of MnPc nanotubes is always increased while the spin-up band gap of MnPc nanotubes approaches that of the 2D MnPc sheet in an oscillatory manner. Because the half-metallic character of MnPc nanotubes is deeply rooted in the distribution of electrons in the energy bands dominated by the Mn 3d atomic orbitals, adsorption of CO molecules on the Mn ions leads to a redistribution of electrons in the Mn 3d orbitals and thus can tune precisely the spin state and electronic transport properties of MnPc nanotubes, demonstrating promising applications of MnPc nanotubes in future molecular spintronics and single-molecule sensors.
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Affiliation(s)
- Hongbin Jiang
- School of Physics & Electronic Engineering, Sichuang Mianyang Normal University, Mianyang 621000, China; E-Mail:
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
| | - Meilin Bai
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
| | - Peng Wei
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
| | - Lili Sun
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
| | - Ziyong Shen
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
| | - Shimin Hou
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; E-Mails: (M.B.); (P.W.); (L.S.); (Z.S.)
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