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Blanco-Rey M, Castrillo R, Ali K, Gargiani P, Ilyn M, Gastaldo M, Paradinas M, Valbuena MA, Mugarza A, Ortega JE, Schiller F, Fernández L. The Role of Rare-Earth Atoms in the Anisotropy and Antiferromagnetic Exchange Coupling at a Hybrid Metal-Organic Interface. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402328. [PMID: 39150001 DOI: 10.1002/smll.202402328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 07/17/2024] [Indexed: 08/17/2024]
Abstract
Magnetic anisotropy and magnetic exchange interactions are crucial parameters that characterize the hybrid metal-organic interface, a key component of an organic spintronic device. It is shown that the incorporation of 4f RE atoms to hybrid metal-organic interfaces of CuPc/REAu2 type (RE = Gd, Ho) constitutes a feasible approach toward on-demand magnetic properties and functionalities. The GdAu2 and HoAu2 substrates differ in their magnetic anisotropy behavior. Remarkably, the HoAu2 surface promotes the inherent out-of-plane anisotropy of CuPc, owing to the match between the anisotropy axis of substrate and molecule. Furthermore, the presence of RE atoms leads to a spontaneous antiferromagnetic exchange coupling at the interface, induced by the 3d-4f superexchange interaction between the unpaired 3d electron of CuPc and the 4f electrons of the RE atoms. It is shown that 4f RE atoms with unquenched quantum orbital momentum ( L $L$ ), as it is the case of Ho, induce an anisotropic interfacial exchange coupling.
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Affiliation(s)
- María Blanco-Rey
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Universidad del País Vasco UPV/EHU, San Sebastián, 20018, Spain
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
- Donostia International Physics Center, Donostia-San Sebastián, 20018, Spain
| | - Rodrigo Castrillo
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
- Donostia International Physics Center, Donostia-San Sebastián, 20018, Spain
| | - Khadiza Ali
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
- Donostia International Physics Center, Donostia-San Sebastián, 20018, Spain
- Chalmers University of Technology, Göteborg, Göteborg, 412 96, Sweden
| | | | - Maxim Ilyn
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
| | - Michele Gastaldo
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Barcelona, 08193, Spain
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague, 18223, Czech Republic
| | - Markos Paradinas
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Barcelona, 08193, Spain
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, Bellaterra, 08193, Spain
| | - Miguel A Valbuena
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Barcelona, 08193, Spain
- Instituto Madrileño de Estudios Avanzados, IMDEA Nanociencia, Madrid, 28049, Spain
| | - Aitor Mugarza
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Barcelona, 08193, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona, 08010, Spain
| | - J Enrique Ortega
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
- Donostia International Physics Center, Donostia-San Sebastián, 20018, Spain
- Departamento de Física Aplicada I, Universidad del País Vasco UPV/EHU, San Sebastián, 20018, Spain
| | - Frederik Schiller
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
| | - Laura Fernández
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, San Sebastián, 20018, Spain
- CIC nanoGUNE-BRTA, San Sebastián, 20018, Spain
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2
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Nowik-Boltyk EM, Junghoefer T, Giangrisostomi E, Ovsyannikov R, Shu C, Rajca A, Droghetti A, Casu MB. Radical-Induced Changes in Transition Metal Interfacial Magnetic Properties: A Blatter Derivative on Polycrystalline Cobalt. Angew Chem Int Ed Engl 2024:e202403495. [PMID: 38843268 DOI: 10.1002/anie.202403495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Indexed: 07/23/2024]
Abstract
In this work, we study the interface obtained by depositing a monolayer of a Blatter radical derivative on polycrystalline cobalt. By examining the occupied and unoccupied states at the interface, using soft X-ray techniques, combined with electronic structure calculations, we could simultaneously determine the electronic structure of both the molecular and ferromagnetic sides of the interface, thus obtaining a full understanding of the interfacial magnetic properties. We found that the molecule is strongly hybridized with the surface. Changes in the core level spectra reflect the modification of the molecule and the cobalt electronic structures inducing a decrease in the magnetic moment of the cobalt atoms bonded to the molecules which, in turn, lose their radical character. Our method allowed us to screen, beforehand, organic/ferromagnetic interfaces given their potential applications in spintronics.
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Affiliation(s)
| | - Tobias Junghoefer
- Institute of Physical and Theoretical Chemistry, University of Tübingen, 72076, Tübingen, Germany
| | - Erika Giangrisostomi
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin, 12489, Berlin, Germany
| | - Ruslan Ovsyannikov
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin, 12489, Berlin, Germany
| | - Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588, United States
| | - Andrea Droghetti
- School of Physics and CRANN, Trinity College, the University of Dublin, Dublin, D02, Ireland
| | - M Benedetta Casu
- Institute of Physical and Theoretical Chemistry, University of Tübingen, 72076, Tübingen, Germany
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3
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Gnoli L, Benini M, Del Conte C, Riminucci A, Rakshit RK, Singh M, Sanna S, Yadav R, Lin KW, Mezzi A, Achilli S, Molteni E, Marino M, Fratesi G, Dediu V, Bergenti I. Enhancement of Magnetic Stability in Antiferromagnetic CoO Films by Adsorption of Organic Molecules. ACS APPLIED ELECTRONIC MATERIALS 2024; 6:3138-3146. [PMID: 38828040 PMCID: PMC11137817 DOI: 10.1021/acsaelm.3c01599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/14/2024] [Accepted: 02/19/2024] [Indexed: 06/05/2024]
Abstract
Antiferromagnets are a class of magnetic materials of great interest in spintronic devices because of their stability and ultrafast dynamics. When interfaced with an organic molecular layer, antiferromagnetic (AF) films are expected to form a spinterface that can allow fine control of specific AF properties. In this paper, we investigate spinterface effects on CoO, an AF oxide. To access the magnetic state of the antiferromagnet, we couple it to a ferromagnetic Co film via an exchange bias (EB) effect. In this way, the formation of a spinterface is detected through changes induced on the CoO/Co EB system. We demonstrate that C60 and Gaq3 adsorption on CoO shifts its blocking temperature; in turn, an increase in both the EB fields and the coercivities is observed on the EB-coupled Co layer. Ab initio calculations for the CoO/C60 interface indicate that the molecular adsorption is responsible for a charge redistribution on the CoO layer that alters the occupation of the d orbitals of Co atoms and, to a smaller extent, the p orbitals of oxygen. As a result, the AF coupling between Co atoms in the CoO is enhanced. Considering the granular nature of CoO, a larger AF stability upon molecular adsorption is then associated with a larger number of AF grains that are stable upon reversal of the Co layer.
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Affiliation(s)
- Luca Gnoli
- CNR
ISMN, Via Gobetti 101, 40129 Bologna, Italy
| | | | - Corrado Del Conte
- Department
of Physics and Astronomy “A. Righi”, University of Bologna, Via Berti-Pichat 6/2, I-40127 Bologna, Italy
| | | | | | - Manju Singh
- CNR
ISMN, Via Gobetti 101, 40129 Bologna, Italy
| | - Samuele Sanna
- Department
of Physics and Astronomy “A. Righi”, University of Bologna, Via Berti-Pichat 6/2, I-40127 Bologna, Italy
| | - Roshni Yadav
- Materials
Science and Engineering Department, National
Chung Hsing University, Taichung 402, Taiwan
| | - Ko-Wei Lin
- Materials
Science and Engineering Department, National
Chung Hsing University, Taichung 402, Taiwan
| | - Alessio Mezzi
- CNR
ISMN, Via Salaria km
29.300, 00015 Monterotondo
Scalo, Italy
| | - Simona Achilli
- Physics
Department, Università degli Studi
di Milano, Via Celoria 16, 20133 Milan, Italy
| | - Elena Molteni
- Physics
Department, Università degli Studi
di Milano, Via Celoria 16, 20133 Milan, Italy
| | - Marco Marino
- Physics
Department, Università degli Studi
di Milano, Via Celoria 16, 20133 Milan, Italy
| | - Guido Fratesi
- Physics
Department, Università degli Studi
di Milano, Via Celoria 16, 20133 Milan, Italy
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4
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Tiwari RK, Nabi R, Kumawat RL, Pathak B, Rajaraman G. Enhancing Spin-Transport Characteristics, Spin-Filtering Efficiency, and Negative Differential Resistance in Exchange-Coupled Dinuclear Co(II) Complexes for Molecular Spintronics Applications. Inorg Chem 2024; 63:316-328. [PMID: 38114426 DOI: 10.1021/acs.inorgchem.3c03200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Single-molecule spintronics, where electron transport occurs via a paramagnetic molecule, has gained wide attention due to its potential applications in the area of memory devices to switches. While numerous organic and some inorganic complexes have been employed over the years, there are only a few attempts to employ exchange coupled dinuclear complexes at the interface, and the advantage of fabricating such a molecular spintronics device in the observation of switchable Kondo resonance was demonstrated recently in the dinuclear [Co2(L)(hfac)4] (1) complex (Wagner et al., Nat. Nanotechnol. 2013, 8, 575-579). In this work, employing an array of theoretical tools such as density functional theory (DFT), the ab initio CASSCF/NEVPT2 method, and DFT combined with nonequilibrium Green Function (NEGF) formalism, we studied in detail the role of magnetic coupling, ligand field, and magnetic anisotropy in the transport characteristics of complex 1. Particularly, our calculations not only reproduce the current-voltage (I-V) characteristics observed in experiments but also unequivocally establish that these arise from an exchange-coupled singlet state that arises due to antiferromagnetic coupling between two high-spin Co(II) centers. Further, the estimated spin Hamiltonian parameters such as J, g values, and D and E/D values are only marginally altered for the molecule at the interface. Further, the exchange-coupled state was found to have very similar transport responses, despite possessing significantly different geometries. Our transport calculations unveil a new feature of the negative differential resistance (NDR) effect on 1 at the bias voltage of 0.9 V, which agrees with the experimental I-V characteristics reported. The spin-filtering efficiency (SFE) computed for the spin-coupled states was found to be only marginal (∼25%); however, if the ligand field is fine-tuned to obtain a low-spin Co(II) center, a substantial SFE of 44% was noted. This spin-coupled state also yields a very strong NDR with a peak-to-valley ratio (PVR) of ∼56 - a record number that has not been witnessed so far in this class of compounds. Additionally, we have established further magnetostructural-transport correlations, providing valuable insights into how microscopic spin Hamiltonian parameters can be associated with SFE. Several design clues to improve the spin-transport characteristics, SFE and NDR in this class of molecule, are offered.
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Affiliation(s)
| | - Rizwan Nabi
- Department of Chemistry, IIT Bombay, Powai, Mumbai 400076, India
| | | | - Biswarup Pathak
- Department of Chemistry, IIT Indore, Indore, Madhya Pradesh 453-552, India
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5
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He Q, Sheng B, Zhu K, Zhou Y, Qiao S, Wang Z, Song L. Phase Engineering and Synchrotron-Based Study on Two-Dimensional Energy Nanomaterials. Chem Rev 2023; 123:10750-10807. [PMID: 37581572 DOI: 10.1021/acs.chemrev.3c00389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
In recent years, there has been significant interest in the development of two-dimensional (2D) nanomaterials with unique physicochemical properties for various energy applications. These properties are often derived from the phase structures established through a range of physical and chemical design strategies. A concrete analysis of the phase structures and real reaction mechanisms of 2D energy nanomaterials requires advanced characterization methods that offer valuable information as much as possible. Here, we present a comprehensive review on the phase engineering of typical 2D nanomaterials with the focus of synchrotron radiation characterizations. In particular, the intrinsic defects, atomic doping, intercalation, and heterogeneous interfaces on 2D nanomaterials are introduced, together with their applications in energy-related fields. Among them, synchrotron-based multiple spectroscopic techniques are emphasized to reveal their intrinsic phases and structures. More importantly, various in situ methods are employed to provide deep insights into their structural evolutions under working conditions or reaction processes of 2D energy nanomaterials. Finally, conclusions and research perspectives on the future outlook for the further development of 2D energy nanomaterials and synchrotron radiation light sources and integrated techniques are discussed.
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Affiliation(s)
- Qun He
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Beibei Sheng
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Kefu Zhu
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Yuzhu Zhou
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Sicong Qiao
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Zhouxin Wang
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Li Song
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230029, China
- Zhejiang Institute of Photonelectronics, Jinhua, Zhejiang 321004, China
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6
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Meng K, Guo L, Sun X. Strategies and applications of generating spin polarization in organic semiconductors. NANOSCALE HORIZONS 2023; 8:1132-1154. [PMID: 37424331 DOI: 10.1039/d3nh00101f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The advent of spintronics has undoubtedly revolutionized data storage, processing, and sensing applications. Organic semiconductors (OSCs), characterized by long spin relaxation times (>μs) and abundant spin-dependent properties, have emerged as promising materials for advanced spintronic applications. To successfully implement spin-related functions in organic spintronic devices, the four fundamental processes of spin generation, transport, manipulation, and detection form the main building blocks and are commonly in demand. Thereinto, the effective generation of spin polarization in OSCs is a precondition, but in practice, this has not been an easy task. In this context, considerable efforts have been made on this topic, covering novel materials systems, spin-dependent theories, and device fabrication technologies. In this review, we underline recent advances in external spin injection and organic property-induced spin polarization, according to the distinction between the sources of spin polarization. We focused mainly on summarizing and discussing both the physical mechanism and representative research on spin generation in OSCs, especially for various spin injection methods, organic magnetic materials, the chiral-induced spin selectivity effect, and the spinterface effect. Finally, the challenges and prospects that allow this topic to continue to be dynamic were outlined.
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Affiliation(s)
- Ke Meng
- Key Laboratory of Nanosystem and Hierarchical Fabrication, 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
| | - Lidan Guo
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
| | - Xiangnan Sun
- Key Laboratory of Nanosystem and Hierarchical Fabrication, 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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7
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Castrillo-Bodero R, Blanco-Rey M, Ali K, Ortega JE, Schiller F, Fernández L. Tuning the carrier injection barrier of hybrid metal-organic interfaces on rare earth-gold surface compounds. NANOSCALE 2023; 15:4090-4100. [PMID: 36744853 DOI: 10.1039/d2nr06440e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Magnetic hybrid metal-organic interfaces possess a great potential in areas such as organic spintronics and quantum information processing. However, tuning their carrier injection barriers on-demand is fundamental for the implementation in technological devices. We have prepared hybrid metal-organic interfaces by the adsorption of copper phthalocyanine CuPc on REAu2 surfaces (RE = Gd, Ho and Yb) and studied their growth, electrostatics and electronic structure. CuPc exhibits a long-range commensurability and a vacuum level pinning of the molecular energy levels. We observe a significant effect of the RE valence of the substrate on the carrier injection barrier of the hybrid metal-organic interface. CuPc adsorbed on trivalent RE-based surfaces (HoAu2 and GdAu2) exhibits molecular level energies that may allow injection carriers significantly closer to an ambipolar injection behavior than in the divalent case (YbAu2).
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Affiliation(s)
- R Castrillo-Bodero
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, 20018 San Sebastián, Spain.
| | - M Blanco-Rey
- Universidad del País Vasco UPV/EHU, Dpto. de Polímeros y Materiales Avanzados: Física, Química y Tecnología, 20018 San Sebastián, Spain
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - K Ali
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, 20018 San Sebastián, Spain.
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
- Chalmers University of Technology, Chalmersplatsen 4, Götenborg, 41296, Sweden
| | - J E Ortega
- Universidad del País Vasco UPV/EHU, Dpto. Física Aplicada I, 20018 San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, 20018 San Sebastián, Spain.
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - F Schiller
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, 20018 San Sebastián, Spain.
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - L Fernández
- Centro de Física de Materiales CSIC-UPV/EHU-Materials Physics Center, 20018 San Sebastián, Spain.
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8
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Chiter F, Costa D, Pébère N, Marcus P, Lacaze-Dufaure C. Insight at the atomic scale of corrosion inhibition: DFT study of 8-hydroxyquinoline on oxidized aluminum surfaces. Phys Chem Chem Phys 2023; 25:4284-4296. [PMID: 36688480 DOI: 10.1039/d2cp04626a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
8-Hydroxyquinoline (8-HQ) is a promising organic molecule for the corrosion protection of aluminum and its alloys in the replacement of chromate salts. On the aluminum surface, the presence of an oxide layer naturally formed can influence the inhibition efficiency which depends on molecule-surface interactions. In the present study, we performed quantum chemical calculations on native 8-HQ, tautomer and 8-Q (deprotonated, H-abstracted or radical) molecules, adsorbed on an oxidized aluminum surface (γ-Al2O3(111)/Al(111)). All species have the ability to interact strongly with the oxidized aluminum surface and can form stable and dense organic films. The bonding strength of different species of 8-HQ on oxidized aluminum surfaces is more favorable for 8-Q and tautomer species than for the native 8-HQ molecule. On the surface, the native 8-HQ molecule is physisorbed, forming H-bonds, in contrast to the tautomer and 8-Q species that show the predominance of chemisorption modes, involving both H-bonds and covalent bonds at the molecule/substrate interface. The dispersion energy significantly contributes to the adsorption mechanism and increases with increasing molecular surface coverage, due to attractive molecule-molecule interactions. Regardless of surface coverage and considered reaction mechanisms, the 8-Q species is able to enhance the stability of all aluminum sites, and thus to slow down the anodic reaction. In contrast, the native molecule and the tautomeric form have no significant effect or even weakened the stability of aluminum surface atoms.
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Affiliation(s)
- Fatah Chiter
- CIRIMAT, Université de Toulouse, CNRS, INPT-ENSIACET 4, allée Emile Monso, BP 44362, 31030 Toulouse Cedex 4, France. .,PSL University, CNRS - Chimie ParisTech, Institut de Recherche de Chimie Paris/Physical Chemistry of Surfaces Group, 11 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Dominique Costa
- PSL University, CNRS - Chimie ParisTech, Institut de Recherche de Chimie Paris/Physical Chemistry of Surfaces Group, 11 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Nadine Pébère
- CIRIMAT, Université de Toulouse, CNRS, INPT-ENSIACET 4, allée Emile Monso, BP 44362, 31030 Toulouse Cedex 4, France.
| | - Philippe Marcus
- PSL University, CNRS - Chimie ParisTech, Institut de Recherche de Chimie Paris/Physical Chemistry of Surfaces Group, 11 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Corinne Lacaze-Dufaure
- CIRIMAT, Université de Toulouse, CNRS, INPT-ENSIACET 4, allée Emile Monso, BP 44362, 31030 Toulouse Cedex 4, France.
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9
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Janas DM, Droghetti A, Ponzoni S, Cojocariu I, Jugovac M, Feyer V, Radonjić MM, Rungger I, Chioncel L, Zamborlini G, Cinchetti M. Enhancing Electron Correlation at a 3d Ferromagnetic Surface. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2205698. [PMID: 36300806 DOI: 10.1002/adma.202205698] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Spin-resolved momentum microscopy and theoretical calculations are combined beyond the one-electron approximation to unveil the spin-dependent electronic structure of the interface formed between iron (Fe) and an ordered oxygen (O) atomic layer, and an adsorbate-induced enhancement of electronic correlations is found. It is demonstrated that this enhancement is responsible for a drastic narrowing of the Fe d-bands close to the Fermi energy (EF ) and a reduction of the exchange splitting, which is not accounted for in the Stoner picture of ferromagnetism. In addition, correlation leads to a significant spin-dependent broadening of the electronic bands at higher binding energies and their merging with satellite features, which are manifestations of a pure many-electron behavior. Overall, adatom adsorption can be used to vary the material parameters of transition metal surfaces to access different intermediate electronic correlated regimes, which will otherwise not be accessible. The results show that the concepts developed to understand the physics and chemistry of adsorbate-metal interfaces, relevant for a variety of research areas, from spintronics to catalysis, need to be reconsidered with many-particle effects being of utmost importance. These may affect chemisorption energy, spin transport, magnetic order, and even play a key role in the emergence of ferromagnetism at interfaces between non-magnetic systems.
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Affiliation(s)
| | - Andrea Droghetti
- School of Physics & CRANN, Trinity College, Dublin, D02 PN40, Ireland
| | - Stefano Ponzoni
- TU Dortmund University, Department of Physics, 44227, Dortmund, Germany
| | - Iulia Cojocariu
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Matteo Jugovac
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Miloš M Radonjić
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, Belgrade, 11080, Serbia
| | - Ivan Rungger
- National Physical Laboratory, Teddington, TW11 0LW, UK
| | - Liviu Chioncel
- Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics and Augsburg Center for Innovative Technologies, University of Augsburg, 86159, Augsburg, Germany
| | | | - Mirko Cinchetti
- TU Dortmund University, Department of Physics, 44227, Dortmund, Germany
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10
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Yu C, Feng Q, Li X, Yang J. Highly interface-dependent spin transport in an Fe-Mn(DBTAA)-Fe single molecule spintronic device. NANOSCALE 2022; 14:15799-15803. [PMID: 36254465 DOI: 10.1039/d2nr03811k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Understanding the spinterface between magnetic electrodes and molecules, and realizing the controllable spin filtering effect, are crucial for the development of high-performance molecular devices, but both still face big challenges. Here, based on first-principles calculations of an Fe-Mn(DBTAA)-Fe single molecule spintronic device, we unveil that spin filtering efficiency is highly dependent on interface configurations, which can modulate and even reverse the spin polarization of tunnelling electrons. For Fe-Mn(DBTAA)-Fe, a varied spin filtering from -93% to +75% is observed. The underlying mechanism could be attributed to the distinct magnetic and electronic couplings between the Fe electrode and the Mn(DBTAA) molecule in different interface configurations. This work not only highlights the importance of a magnetic electrode-molecule interface, but also implies that through suitable interface design, the performance, e.g., of the spin filtering channel of single molecule spintronic devices, can be flexibly tuned.
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Affiliation(s)
- Cuiju Yu
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Qingqing Feng
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xingxing Li
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
| | - Jinlong Yang
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
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11
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Zlobin IS, Aisin RR, Novikov VV. Iron(II) Clathrochelates in Molecular Spintronic Devices: A Vertical Spin Valve. RUSS J COORD CHEM+ 2022. [DOI: 10.1134/s1070328422010080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
The thermal sublimation of the known cage iron(II) complex (clathrochelate) gives thin films of this compound on various supports without violating its integrity as shown by electron spectroscopy. The spin state of the complex remains unchanged compared to the polycrystalline sample and solution. The first prototypes of molecular spintronic devices in the form of a vertical spin valve are prepared from the chosen iron(II) clathrochelate, and their electron transport properties are studied.
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12
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Li D, Frauenheim T, He J. Robust Giant Magnetoresistance in 2D Van der Waals Molecular Magnetic Tunnel Junctions. ACS APPLIED MATERIALS & INTERFACES 2021; 13:36098-36105. [PMID: 34308645 DOI: 10.1021/acsami.1c10673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The spin transport across a zero-dimensional (0D) single-molecule sandwiched by two-dimensional (2D) van der Waals (vdW) ferromagnetic electrodes may open vast opportunities to create novel mixed-dimensional spintronics devices. However, this remains unexplored yet. Inspired by the recent discovery of 2D intrinsic ferromagnets Fe3GeTe2, using first-principles spin transport calculations, we show that single-molecule junctions based on Fe3GeTe2 can yield perfect spin filtering and a significant magnetoresistance (MR) of up to ∼6075%. This remarkable MR is more than 2 orders of magnitude higher than the MR obtained for the corresponding junctions with conventional ferromagnetic metals (e.g., Ni, Fe, and Co). We demonstrate the results of two representative examples that are feasible in the experiments: (i) A benzene or (ii) bezenedithiol (BDT) connected either through a scanning tunneling microscope or break-junction setups. We find that the conductance of BDT junctions is more than 10 times larger than that of the benzene junction due to a much stronger hybridization effect at the molecule-metal interfaces. The key mechanism of the perfect spin filtering and large MR in single-molecule junctions is mainly determined by the intrinsic properties of Fe3GeTe2 electrodes, while the actual conductance is determined by the hybridization strength of the majority spin channel at the molecule-metal interfaces. It is also predicted that the perfect spin filtering and the remarkably huge MR are highly insensitive to structural variations, interface defects, and stacking orders of the electrodes. Our results provide important insights for expanding molecular spintronics platforms from conventional ferromagnetic metals to new 2D vdw magnets.
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Affiliation(s)
- Dongzhe Li
- Institute for Advanced Study, Chengdu University, Chengdu 610100, P. R. China
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835 Bremen, Germany
| | - Junjie He
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835 Bremen, Germany
- Department of Physical and Macromolecular Chemistry & Charles University Centre of Advanced Materials, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague 2, Czech Republic
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13
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Eschenlohr A. Spin dynamics at interfaces on femtosecond timescales. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:013001. [PMID: 33034305 DOI: 10.1088/1361-648x/abb519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The excitation of magnetically ordered materials with ultrashort laser pulses results in magnetization dynamics on femto- to picosecond timescales. These non-equilibrium spin dynamics have emerged as a rapidly developing research field in recent years. Unraveling the fundamental microscopic processes in the interaction of ultrashort optical pulses with the charge, spin, orbital, and lattice degrees of freedom in magnetic materials shows the potential for controlling spin dynamics on their intrinsic timescales and thereby bring spintronics applications into the femtosecond range. In particular, femtosecond spin currents offer fascinating new possibilities to manipulate magnetization in an ultrafast and non-local manner, via spin injection and spin transfer torque at the interfaces of ferromagnetic layered structures. This topical review covers recent progress on spin dynamics at interfaces on femtosecond time scales. The development of the field of ultrafast spin dynamics in ferromagnetic heterostructures will be reviewed, starting from spin currents propagating on nanometer length scales through layered structures before focusing on femtosecond spin transfer at interfaces. The properties of these ultrafast spin-dependent charge currents will be discussed, as well as the materials dependence of femtosecond spin injection, the role of the interface properties, and competing microscopic processes leading to a loss of spin polarization on sub-picosecond timescales.
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Affiliation(s)
- A Eschenlohr
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
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14
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Bonnet R, Martin P, Suffit S, Lafarge P, Lherbier A, Charlier JC, Della Rocca ML, Barraud C. Giant spin signals in chemically functionalized multiwall carbon nanotubes. SCIENCE ADVANCES 2020; 6:eaba5494. [PMID: 32789172 PMCID: PMC7399653 DOI: 10.1126/sciadv.aba5494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Transporting quantum information such as the spin information over micrometric or even millimetric distances is a strong requirement for the next-generation electronic circuits such as low-voltage spin-logic devices. This crucial step of transportation remains delicate in nontopologically protected systems because of the volatile nature of spin states. Here, a beneficial combination of different phenomena is used to approach this sought-after milestone for the beyond-Complementary Metal Oxide Semiconductor (CMOS) technology roadmap. First, a strongly spin-polarized charge current is injected using highly spin-polarized hybridized states emerging at the complex ferromagnetic metal/molecule interfaces. Second, the spin information is brought toward the conducting inner shells of a multiwall carbon nanotube used as a confined nanoguide benefiting from both weak spin-orbit and hyperfine interactions. The spin information is finally electrically converted because of a strong magnetoresistive effect. The experimental results are also supported by calculations qualitatively revealing exceptional spin transport properties of this system.
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Affiliation(s)
- Roméo Bonnet
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Pascal Martin
- Université de Paris, ITODYS, CNRS, UMR 7086, 75013 Paris, France
| | - Stéphan Suffit
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Philippe Lafarge
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Aurélien Lherbier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Maria Luisa Della Rocca
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Clément Barraud
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
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15
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Bulteau Y, Tarrat N, Pébère N, Lacaze-Dufaure C. 8-Hydroxyquinoline complexes (Alq3) on Al(111): atomic scale structure, energetics and charge distribution. NEW J CHEM 2020. [DOI: 10.1039/d0nj02824j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
8-Hydroxyquinoline (8Hq) is known to efficiently inhibit the corrosion of aluminium by forming metal–organic layers (8Hq forms complexes with aluminium atoms).
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Affiliation(s)
- Yann Bulteau
- CIRIMAT
- Université de Toulouse
- CNRS
- INP-ENSIACET
- Toulouse cedex 31030
| | | | - Nadine Pébère
- CIRIMAT
- Université de Toulouse
- CNRS
- INP-ENSIACET
- Toulouse cedex 31030
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16
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Zhang X, Tong J, Ruan L, Yao X, Zhou L, Tian F, Qin G. Interface hybridization and spin filter effect in metal-free phthalocyanine spin valves. Phys Chem Chem Phys 2020; 22:11663-11670. [DOI: 10.1039/d0cp00651c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin–orbit coupling has been regarded as the core interaction to determine the efficiency of spin conserved transport in semiconductor spintronics. Here, we show the spin filter effect should be responsible for the magnetoresistance of H2Pc device.
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Affiliation(s)
- Xianmin Zhang
- School of Material Science and Engineering
- Northeastern University
- Shenyang 110819
- China
- State Key Laboratory of Rolling and Automation
| | - Junwei Tong
- School of Material Science and Engineering
- Northeastern University
- Shenyang 110819
- China
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education)
| | - Liuxia Ruan
- School of Material Science and Engineering
- Northeastern University
- Shenyang 110819
- China
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education)
| | - Xiannian Yao
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education)
- Northeastern University
- Shenyang 110819
- China
| | - Lianqun Zhou
- Suzhou Institute of Biomedical, Engineering and Technology
- Chinese Academy of Sciences
- Suzhou 215163
- China
| | - Fubo Tian
- State Key Laboratory of Superhard Materials
- College of Physics
- Jilin University
- Changchun 130012
- China
| | - Gaowu Qin
- School of Material Science and Engineering
- Northeastern University
- Shenyang 110819
- China
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education)
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17
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18
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Jo J, Byun J, Oh I, Park J, Jin MJ, Min BC, Lee J, Yoo JW. Molecular Tunability of Magnetic Exchange Bias and Asymmetrical Magnetotransport in Metalloporphyrin/Co Hybrid Bilayers. ACS NANO 2019; 13:894-903. [PMID: 30557507 DOI: 10.1021/acsnano.8b08689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Individual molecular spins are promising quantum states for emerging computation technologies. The "on surface" configuration of molecules in proximity to a magnetic film allows control over the orientations of molecular spins and coupling between them. The stacking of planar molecular spins could favor antiferromagnetic interlayer couplings and lead to pinning of the magnetic underlayer via the exchange bias, which is extensively utilized in ultrafast and high-density spintronics. However, fundamental understanding of the molecular exchange bias and its operating features on a device has not been unveiled. Here, we showed tunable molecular exchange bias and its asymmetrical magnetotransport characteristics on a device by using the metalloporphyrin/cobalt hybrid films. A series of the distinctive molecular layers showcased a wide range of the interfacial exchange coupling and bias. The transport behaviors of the hybrid bilayer films revealed the molecular exchange bias effect on a fabricated device, representing asymmetric characteristics on anisotropic and angle-dependent magnetoresistances. Theoretical simulations demonstrated close correlations among the interfacial distance, magnetic interaction, and exchange bias. This study of the hybrid interfacial coupling and its impact on magnetic and magnetotransport behaviors will extend functionalities of molecular spinterfaces for emerging information technologies.
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Affiliation(s)
- Junhyeon Jo
- School of Materials Science and Engineering/Low-Dimensional Carbon Materials Center , Ulsan National Institute of Science and Technology , Ulsan 44919 , Korea
| | - Jinho Byun
- Department of Physics , Pusan National University , Busan 46241 , Korea
| | - Inseon Oh
- School of Materials Science and Engineering/Low-Dimensional Carbon Materials Center , Ulsan National Institute of Science and Technology , Ulsan 44919 , Korea
| | - Jungmin Park
- School of Materials Science and Engineering/Low-Dimensional Carbon Materials Center , Ulsan National Institute of Science and Technology , Ulsan 44919 , Korea
| | - Mi-Jin Jin
- School of Materials Science and Engineering/Low-Dimensional Carbon Materials Center , Ulsan National Institute of Science and Technology , Ulsan 44919 , Korea
| | - Byoung-Chul Min
- Center for Spintronics , Korea Institute of Science and Technology , Seoul 02792 , Korea
| | - Jaekwang Lee
- Department of Physics , Pusan National University , Busan 46241 , Korea
| | - Jung-Woo Yoo
- School of Materials Science and Engineering/Low-Dimensional Carbon Materials Center , Ulsan National Institute of Science and Technology , Ulsan 44919 , Korea
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19
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Barraud C, Lemaitre M, Bonnet R, Rastikian J, Salhani C, Lau S, van Nguyen Q, Decorse P, Lacroix JC, Della Rocca ML, Lafarge P, Martin P. Charge injection and transport properties of large area organic junctions based on aryl thin films covalently attached to a multilayer graphene electrode. NANOSCALE ADVANCES 2019; 1:414-420. [PMID: 36132450 PMCID: PMC9473172 DOI: 10.1039/c8na00106e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/25/2018] [Indexed: 06/15/2023]
Abstract
The quantum interaction between molecules and electrode materials at molecule/electrode interfaces is a major ingredient in the electron transport properties of organic junctions. Driven by the coupling strength between the two materials, it results mainly in the broadening and energy shift of the interacting molecular orbitals. Using new electrode materials, such as the recently developed semi-conducting two-dimensional nanomaterials, has become a significant advancement in the field of molecular/organic electronics that opens new possibilities for controlling the interfacial electronic properties and thus the charge injection properties. In this article, we report the use of atomically thin two-dimensional multilayer graphene films as the base electrode in organic junctions with a vertical architecture. The interfacial electronic structure dominated by the covalent bonding between bis-thienyl benzene diazonium-based molecules and the multilayer graphene electrode has been probed by ultraviolet photoelectron spectroscopy and the results are compared with those obtained on junctions with standard Au electrodes. Room temperature injection properties of such interfaces have also been explored by electron transport measurements. We find that, despite strong variations of the density of states, the Fermi energy and the injection barriers, both organic junctions with Au base electrodes and multilayer graphene base electrodes show similar electronic responses. We explain this observation by the strong orbital coupling occurring at the bottom electrode/bis-thienyl benzene molecule interface and by the pinning of the hybridized molecular orbitals.
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Affiliation(s)
- Clément Barraud
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Matthieu Lemaitre
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Roméo Bonnet
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Jacko Rastikian
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Chloé Salhani
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Stéphanie Lau
- ITODYS UMR 7086, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Quyen van Nguyen
- ITODYS UMR 7086, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
- Department of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet CauGiay Hanoi Vietnam
| | - Philippe Decorse
- ITODYS UMR 7086, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | | | | | - Philippe Lafarge
- MPQ UMR 7162, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
| | - Pascal Martin
- ITODYS UMR 7086, Université Paris Diderot, Sorbonne Paris Cité, CNRS F-75013 Paris France
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20
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Lach S, Altenhof A, Shi S, Fahlman M, Ziegler C. Electronic and magnetic properties of a ferromagnetic cobalt surface by adsorbing ultrathin films of tetracyanoethylene. Phys Chem Chem Phys 2019; 21:15833-15844. [PMID: 31282504 DOI: 10.1039/c9cp02205h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Ultrathin films of tetracyanoethylene (TCNE) on Co(100) were investigated by means of spin-integrated and spin-resolved photoemission spectroscopy ((sp-)UPS), X-ray photoemission spectroscopy (XPS), near edge X-ray absorption fine-structure spectroscopy (NEXAFS), and X-ray magnetic circular dichroism (XMCD). We found a coverage-dependent modulation of the interface dipole and a switching between a metallic and a resistive spin filtering at the interface triggered by two distinct adsorption geometries of TCNE. The strongest hybridization and spin structure modifications are found at low coverage with a face-on adsorption geometry indicating changes in the distance between the surface Co atoms beneath. TCNE has the potential to manipulate the magnetic moments in the Co surface itself, including the possibility of magnetic hardening effects. In summary, the system TCNE/Co offers an experimentally rather easy and controllable way to build up a stable molecular platform stabilizing the reactive ferromagnetic Co surface and customizing the electronic and magnetic properties of the resulting spinterface simultaneously. This makes this system very attractive for spintronic applications as an alternative, less reactive but highly spin polarized foundation beside graphene-based systems.
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Affiliation(s)
- Stefan Lach
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, 67663 Kaiserslautern, Germany.
| | - Anna Altenhof
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, 67663 Kaiserslautern, Germany.
| | - Shengwei Shi
- Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430205 Wuhan, China and Department of Physics, Chemistry and Biology, University of Linköping, Linköping, 58183 Linköping, Sweden
| | - Mats Fahlman
- Department of Physics, Chemistry and Biology, University of Linköping, Linköping, 58183 Linköping, Sweden
| | - Christiane Ziegler
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, 67663 Kaiserslautern, Germany.
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21
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Abadía M, Ilyn M, Piquero-Zulaica I, Gargiani P, Rogero C, Ortega JE, Brede J. Polymerization of Well-Aligned Organic Nanowires on a Ferromagnetic Rare-Earth Surface Alloy. ACS NANO 2017; 11:12392-12401. [PMID: 29161499 DOI: 10.1021/acsnano.7b06374] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The high reactivity of magnetic substrates toward molecular overlayers has so far inhibited the realization of more sophisticated on-surface reactions, thereby depriving these interfaces of a significant class of chemically tailored organics such as graphene nanoribbons, oligonuclear spin-chains, and metal-organic networks. Here, we present a multitechnique characterization of the polymerization of 4,4″-dibromo-p-terphenyl precursors into ordered poly(p-phenylene) arrays on top of the bimetallic GdAu2 surface alloy. The activation temperatures for bromine scission and subsequent homocoupling of molecular precursors were followed by temperature-dependent X-ray photoelectron spectroscopy. The structural characterizations of supramolecular and polymeric phases, performed by low-energy electron diffraction and scanning tunneling microscopy, establish an extraordinary degree of order extending into the mesoscale. Taking advantage of the high homogeneity, the electronic structure of the valence band was determined with angle-resolved photoemission spectroscopy. Importantly, the transition of localized molecular orbitals into a highly dispersive π-band, the fingerprint of successful polymerization, was observed while leaving all surface-related bands intact. Moreover, ferromagnetic ordering in the GdAu2 alloy was demonstrated for all phases by X-ray absorption spectroscopy. The transfer of well-established in situ methods for growing covalently bonded macromolecules with atomic precision onto magnetic rare-earth alloys is an important step toward toward studying and controlling intrinsic carbon- and rare-earth-based magnetism.
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Affiliation(s)
- Mikel Abadía
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
| | - Maxim Ilyn
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
- Donostia International Physics Center , Paseo Manuel Lardizabal 4, E-20018 San Sebastián, Spain
| | - Ignacio Piquero-Zulaica
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
| | - Pierluigi Gargiani
- ALBA Synchrotron Light Source , Carretera BP 1413 km 3.3, E-08290 Cerdanyola del Vallés, Spain
| | - Celia Rogero
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
- Donostia International Physics Center , Paseo Manuel Lardizabal 4, E-20018 San Sebastián, Spain
| | - José Enrique Ortega
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
- Donostia International Physics Center , Paseo Manuel Lardizabal 4, E-20018 San Sebastián, Spain
- Departamento Física Aplicada I, Universidad del País Vasco , 20018 San Sebastián, Spain
| | - Jens Brede
- Centro de Física de Materiales CFM - MPC, Centro Mixto CSIC-UPV/EHU , Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
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22
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Cinchetti M, Dediu VA, Hueso LE. Activating the molecular spinterface. NATURE MATERIALS 2017; 16:507-515. [PMID: 28439116 DOI: 10.1038/nmat4902] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 03/23/2017] [Indexed: 05/19/2023]
Abstract
The miniaturization trend in the semiconductor industry has led to the understanding that interfacial properties are crucial for device behaviour. Spintronics has not been alien to this trend, and phenomena such as preferential spin tunnelling, the spin-to-charge conversion due to the Rashba-Edelstein effect and the spin-momentum locking at the surface of topological insulators have arisen mainly from emergent interfacial properties, rather than the bulk of the constituent materials. In this Perspective we explore inorganic/molecular interfaces by looking closely at both sides of the interface. We describe recent developments and discuss the interface as an ideal platform for creating new spin effects. Finally, we outline possible technologies that can be generated thanks to the unique active tunability of molecular spinterfaces.
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Affiliation(s)
- Mirko Cinchetti
- Experimentelle Physik VI, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - V Alek Dediu
- Istituto per lo Studio dei Materiali Nanostrutturati CNRISMN, 40129 Bologna, Italy
| | - Luis E Hueso
- CIC nanoGUNE, 20018 San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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23
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Großmann N, Magri A, Laux M, Stadtmüller B, Thielen P, Schäfer B, Fuhr O, Ruben M, Cinchetti M, Aeschlimann M. Controlled manipulation of the Co–Alq3 interface by rational design of Alq3 derivatives. Dalton Trans 2016; 45:18365-18376. [DOI: 10.1039/c6dt03183h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Recently, research has revealed that molecules can be used to steer the local spin properties of ferromagnetic surfaces.
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Affiliation(s)
- Nicolas Großmann
- Fachbereich Physik and Research Center OPTIMAS
- Technische Universität Kaiserslautern
- 67663 Kaiserslautern
- Germany
| | - Andrea Magri
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- 76344 Leopoldshafen-Eggenstein
- Germany
| | - Martin Laux
- Fachbereich Physik and Research Center OPTIMAS
- Technische Universität Kaiserslautern
- 67663 Kaiserslautern
- Germany
| | - Benjamin Stadtmüller
- Fachbereich Physik and Research Center OPTIMAS
- Technische Universität Kaiserslautern
- 67663 Kaiserslautern
- Germany
- Graduate School of Excellence Materials Science in Mainz
| | - Philip Thielen
- Fachbereich Physik and Research Center OPTIMAS
- Technische Universität Kaiserslautern
- 67663 Kaiserslautern
- Germany
- Graduate School of Excellence Materials Science in Mainz
| | - Bernhard Schäfer
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- 76344 Leopoldshafen-Eggenstein
- Germany
| | - Olaf Fuhr
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- 76344 Leopoldshafen-Eggenstein
- Germany
| | - Mario Ruben
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- 76344 Leopoldshafen-Eggenstein
- Germany
- Institute de Physique et Chimie de Matériaux de Strasbourg (IPCMS)
| | - Mirko Cinchetti
- Experimentelle Physik VI
- Technische Universität Dortmund
- 44221 Dortmund
- Germany
| | - Martin Aeschlimann
- Fachbereich Physik and Research Center OPTIMAS
- Technische Universität Kaiserslautern
- 67663 Kaiserslautern
- Germany
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