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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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Mukhopadhyaya A, Ali ME. Can Iron-Porphyrins Behave as Single-Molecule Magnets? J Phys Chem A 2024. [PMID: 38504619 DOI: 10.1021/acs.jpca.4c00430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The study of magnetic properties, especially the magnetic anisotropy of iron-porphyrin complexes employing multiconfigurational methods, is quite challenging due to many strongly correlated electrons in nearly degenerate orbitals. However, a prerequisite for observing the magnetic anisotropy and slow magnetization relaxation, the zero-field splitting parameter, D, was experimentally observed decades ago for halide-based axially ligated penta-coordinate Fe(III)-porphyrins. In these complexes, the signs of D were reported mostly as positive; in a few cases, inconclusive signs of the D parameter were also mentioned. However, no ab initio calculations have been reported to shed light on this. Deciphering the electronic structure of these penta-coordinated complexes employing the complete active space self-consistent field method and N-electron valence second-order perturbation theory, we confirm the positive D values. However, a negative D value is highly desired to observe the single-molecule magnet properties without an external magnetic field, which we observed in the Fe(II)-porphyrin complexes with axial imidazole ligands instead of halide ligands. The detailed analysis of the multireference wave functions unravels the role of axial ligands in determining the sign and magnitude of the D parameters.
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Affiliation(s)
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Mohali, Punjab 140306, India
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Preparation of a biomimetic Cu(II) protoporphyrin magnetic nanocomposite and its application for the selective adsorption of angiotensin I. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Cobalt porphyrin supported on graphene/Ni (111) surface: Enhanced oxygen evolution/reduction reaction and the role of electron coupling. Catal Today 2020. [DOI: 10.1016/j.cattod.2018.10.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Arruda LM, Ali ME, Bernien M, Hatter N, Nickel F, Kipgen L, Hermanns CF, Bißwanger T, Loche P, Heinrich BW, Franke KJ, Oppeneer PM, Kuch W. Surface-orientation- and ligand-dependent quenching of the spin magnetic moment of Co porphyrins adsorbed on Cu substrates. Phys Chem Chem Phys 2020; 22:12688-12696. [PMID: 32458937 DOI: 10.1039/d0cp00854k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Porphyrin molecules are particularly interesting candidates for spintronic applications due to their bonding flexibility, which allows to modify their properties substantially by the addition or transformation of ligands. Here, we investigate the electronic and magnetic properties of cobalt octaethylporphyrin (CoOEP), deposited on copper substrates with two distinct crystallographic surface orientations, Cu(100) and Cu(111), with X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD). A significant magnetic moment is present in the Co ions of the molecules deposited on Cu(100), but it is completely quenched on Cu(111). Heating the molecules on both substrates to 500 K induces a ring-closure reaction with cobalt tetrabenzoporphyrin (CoTBP) as reaction product. In these molecules, the magnetic moment is quenched on both surfaces. Our XMCD and XAS measurements suggest that the filling of the dz2 orbital leads to a non-integer valence state and causes the quench of the spin moments on all samples except CoOEP/Cu(100), where the molecular conformation induces variations to the ligand field that lift the quench. We further employ density functional theory calculations, supplemented with on-site Coulomb correlations (DFT+U), to study the adsorption of these spin-bearing molecules on the Cu substrates. Our calculations show that charge transfer from the Cu substrates as well as charge redistribution within the Co 3d orbitals lead to the filling of the Co minority spin dz2 orbital, causing a 'turning off' of the exchange splitting and quenching of the spin moment at the Co magnetic centers. Our investigations suggest that, by this mechanism, molecule-substrate interactions can be used to control the quenching of the magnetic moments of the adsorbed molecules.
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Affiliation(s)
- Lucas M Arruda
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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Abstract
We introduce a computational approach to study porphyrin-like transition metal complexes, bridging density functional theory and exact many-body techniques, such as the density matrix renormalization group (DMRG). We first derive a multi-orbital Anderson impurity Hamiltonian starting from first principles considerations that qualitatively reproduce generalized gradient approximation (GGA)+U results when ignoring inter-orbital Coulomb repulsion U ′ and Hund exchange J. An exact canonical transformation is used to reduce the dimensionality of the problem and make it amenable to DMRG calculations, including all many-body terms (both intra- and inter-orbital), which are treated in a numerically exact way. We apply this technique to FeN 4 centers in graphene and show that the inclusion of these terms has dramatic effects: as the iron orbitals become single occupied due to the Coulomb repulsion, the inter-orbital interaction further reduces the occupation, yielding a non-monotonic behavior of the magnetic moment as a function of the interactions, with maximum polarization only in a small window at intermediate values of the parameters. Furthermore, U ′ changes the relative position of the peaks in the density of states, particularly on the iron d z 2 orbital, which is expected to affect the binding of ligands greatly.
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Xie H, Qie Y, Muhammad I, Sun Q. 2D CrCl 2(pyrazine) 2 monolayer: high-temperature ferromagnetism and half-metallicity. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:135801. [PMID: 31778979 DOI: 10.1088/1361-648x/ab5ca4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ferromagnetism in Cr-based monolayers is of current interest (2019 Nat. Nanotechnol. 14 408), however, the Curie temperature is low. How can we enhance the thermal stability of ferromagnetism? Motivated by the recent synthesis of the layered conductive magnet CrCl2(pyrazine)2 (2018 Nat. Chem. 10 1056), we perform first-principles calculations and Monte Carlo simulations to demonstrate that the exfoliated 2D CrCl2(pyrazine)2 monolayer is stable dynamically and thermally, and it is a ferromagnetic half-metal with a sizeable band gap of 2.8 eV in the semiconducting channel, and the strong in-plane Cr-Cr interaction results in a large magnetic anisotropy energy. Moreover, the sheet exhibits a high Curie temperature of 350 K due to the enhanced magnetic exchange interaction resulting from the aromatic property of pyrazine. All of these intriguing features endow 2D CrCl2(pyrazine)2 sheet with good potentials for applications in nanoscale spintronics devices.
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Affiliation(s)
- Huanhuan Xie
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China
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Chen HQ, Shan H, Zhao AD, Li B. First-Principles study of two dimensional transition metal phthalocyanine-based metal-organic frameworks in kagome lattice. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1810227] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Hao-qi Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Huan Shan
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Ai-di Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Bin Li
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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Zhang LC, Zhang L, Qin G, Zheng QR, Hu M, Yan QB, Su G. Two-dimensional magnetic metal-organic frameworks with the Shastry-Sutherland lattice. Chem Sci 2019; 10:10381-10387. [PMID: 32110327 PMCID: PMC6988603 DOI: 10.1039/c9sc03816g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/24/2019] [Indexed: 01/05/2023] Open
Abstract
Mn-PBP is discovered to be the first ferromagnetic 2D MOF with the Shastry-Sutherland lattice and the predicted Curie temperature is 105 K.
Inspired by the successful synthesis of Fe/Cu-5,5′-bis(4-pyridyl)(2,2′-bipirimidine) (PBP), a family of two-dimensional (2D) metal–organic frameworks (MOFs) with the Shastry-Sutherland lattice, i.e., transition metal (TM)-PBP (TM = Cr, Mn, Fe, Co, Ni, Cu, Zn) has been systematically investigated by means of first-principles density functional theory calculations and Monte Carlo simulations. Mn-PBP is discovered to be the first ferromagnetic 2D MOF with the Shastry-Sutherland lattice and the Curie temperature is predicted to be about 105 K, while Fe-PBP, TM-PBP (TM = Cr, Co, Ni) and TM-PBP (TM = Cu, Zn) are found to be stripe-order antiferromagnetic, magnetic-dimerized and nonmagnetic, respectively. The electronic structure calculations reveal that TM-PBP MOFs are semiconductors with band gaps ranging from 0.12 eV to 0.85 eV, which could be easily modulated by various methods. Particularly, Mn-PBP would exhibit half-metallic behavior under compressive strain or appropriate electron/hole doping and a Mn-PBP based spintronic device has been proposed. This study not only improves the understanding of the geometric, electronic and magnetic properties of the 2D TM-PBP MOF family, but also provides a novel spin lattice playground for the research of 2D magnetic systems, which has diverse modulating possibilities and rich potential applications.
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Affiliation(s)
- Li-Chuan Zhang
- Center of Materials Science and Optoelectronics Engineering , College of Materials Science and Opto-Electronic Technology , University of Chinese Academy of Sciences , Beijing 100049 , China . .,Peter Grünberg Institut and Institute for Advanced Simulation , Forschungszentrum Jülich , JARA , 52425 Jülich , Germany.,Department of Physics , RWTH Aachen University , 52056 Aachen , Germany
| | - Lizhi Zhang
- Department of Physics and Astronomy , University of Tennessee , Knoxville , Tennessee 37916 , USA
| | - Guangzhao Qin
- Department of Mechanical Engineering , University of South Carolina , Columbia , SC 29208 , USA .
| | - Qing-Rong Zheng
- School of Physics , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Ming Hu
- Department of Mechanical Engineering , University of South Carolina , Columbia , SC 29208 , USA .
| | - Qing-Bo Yan
- Center of Materials Science and Optoelectronics Engineering , College of Materials Science and Opto-Electronic Technology , University of Chinese Academy of Sciences , Beijing 100049 , China .
| | - Gang Su
- School of Physics , University of Chinese Academy of Sciences , Beijing 100049 , China.,CAS Center for Excellence in Topological Quantum Computation , Kavli Institute for Theoretical Sciences , University of Chinese Academy of Sciences , Beijing 100190 , China .
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Wang Q, Song M, Song X, Bu Y. Unexpected diradical character and large magnetic spin coupling in modified porphyrins induced by inverting pyrrole rings. Phys Chem Chem Phys 2019; 21:17209-17220. [PMID: 31343647 DOI: 10.1039/c9cp02691f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Porphyrin derivatives with inverted pyrrole rings have been experimentally synthesized, and their relevant electronic and magnetic properties have great application prospects in terms of electronic devices. In this work, we rationally design the structures and computationally investigate the electronic properties of porphine and Mg/Zn-porphyrin derivatives with two inverted pyrrole rings, i.e. the dipyrrole-inverted porphine and Mg/Zn-porphyrin analogues (1NN-2H, 2NN-2H, 1NN-Mg, 2NN-Mg, 1NN-Zn and 2NN-Zn), at the B3LYP/6-311G(d,p) level. The main structural characters of these porphyrin derivatives are that the [double bond splayed left]NH units of two pyrrole rings are inverted outwards and the porphyrin-like macrocycles are distorted from square to diamond shapes. More interestingly, these dipyrrole-inverted porphyrin derivatives present diradical characters with noticeably large antiferromagnetic spin coupling constants, i.e.-982.2/-936.3 cm-1 for 1NN-2H/2NN-2H, -796.3/-764.2 cm-1 for 1NN-Mg/2NN-Mg and -1044.5/-1055.2 cm-1 for 1NN-Zn/2NN-Zn, but their monopyrrole-inverted counterparts do not. Examinations of the orbital properties featuring large occupation numbers of the lowest unoccupied natural orbitals and two singly occupied molecular orbitals that are polarized in opposite directions also confirm these findings. These porphyrin derivatives have small singlet-triplet energy gaps and small energy gaps between the highest occupied molecular orbital and lowest unoccupied molecular orbital of the closed-shell singlet states. These are conducive to the emergence of diradical character and large spin coupling constants. Furthermore, the spin-alternation analyses show that each dipyrrole-inverted porphyrin derivative has two resonant structures featuring two spin-opposite single electrons, in agreement with the observed antiferromagnetic spin couplings. This work provides novel insights into the electronic structures and properties of the porphyrin derivatives with modified structures and also provides helpful information for the rational design, synthesis and characterization of new porphyrin-based magnets.
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Affiliation(s)
- Qi Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Meiyu Song
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Xinyu Song
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
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Guan X, Zhu G, Zhang Y, Cao J. The modulation of the magnetocrystalline anisotropy of the halogen functionalize metal-phthalocyanine networks. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.05.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Balle D, Schedel C, Chassé T, Peisert H. Interface properties of CoPc and CoPcF 16 on graphene/nickel: influence of germanium intercalation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:174004. [PMID: 30695754 DOI: 10.1088/1361-648x/ab028f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Photoelectron spectroscopy was used to investigate electronic interface properties and interactions of the organic semiconductors CoPc and CoPcF16 on graphene/nickel based substrates. Additional focus was put on the influence of germanium intercalation of graphene/nickel. The presented results demonstrate that germanium can decouple graphene from nickel and in this manner restore its buffer layer properties. No charge transfer from the substrate to the organic layer is observed in the germanium intercalated case, while interface related peaks in the Co 2p core level spectra indicate such charge transfer on graphene/nickel. Strong interface dipoles are found for CoPcF16 on graphene/nickel and on germanium intercalated graphene/nickel. Fluorine Auger parameters have been measured, and the results provide evidence for polarization and charge transfer screening effects of different amounts at the unlike film-substrate interfaces. The various contributions to the observed shifts are discussed.
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Affiliation(s)
- David Balle
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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Huttmann F, Rothenbach N, Kraus S, Ollefs K, Arruda LM, Bernien M, Thonig D, Delin A, Fransson J, Kummer K, Brookes NB, Eriksson O, Kuch W, Michely T, Wende H. Europium Cyclooctatetraene Nanowire Carpets: A Low-Dimensional, Organometallic, and Ferromagnetic Insulator. J Phys Chem Lett 2019; 10:911-917. [PMID: 30717591 DOI: 10.1021/acs.jpclett.8b03711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigate the magnetic and electronic properties of europium cyclooctatetraene (EuCot) nanowires by means of low-temperature X-ray magnetic circular dichroism (XMCD) and scanning tunneling microscopy (STM) and spectroscopy (STS). The EuCot nanowires are prepared in situ on a graphene surface. STS measurements identify EuCot as an insulator with a minority band gap of 2.3 eV. By means of Eu M5,4 edge XMCD, orbital and spin magnetic moments of (-0.1 ± 0.3)μB and (+7.0 ± 0.6)μB, respectively, were determined. Field-dependent measurements of the XMCD signal at the Eu M5 edge show hysteresis for grazing X-ray incidence at 5 K, thus confirming EuCot as a ferromagnetic material. Our density functional theory calculations reproduce the experimentally observed minority band gap. Modeling the experimental results theoretically, we find that the effective interatomic exchange interaction between Eu atoms is on the order of millielectronvolts, that magnetocrystalline anisotropy energy is roughly half as big, and that dipolar energy is approximately ten times lower.
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Affiliation(s)
- Felix Huttmann
- II. Physikalisches Institut , Universität zu Köln , Zülpicher Strasse 77 , D-50937 Köln , Germany
| | - Nico Rothenbach
- Fakultät für Physik , Universität Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) , Lotharstr. 1 , D-47057 Duisburg , Germany
| | - Stefan Kraus
- II. Physikalisches Institut , Universität zu Köln , Zülpicher Strasse 77 , D-50937 Köln , Germany
| | - Katharina Ollefs
- Fakultät für Physik , Universität Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) , Lotharstr. 1 , D-47057 Duisburg , Germany
| | - Lucas M Arruda
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Matthias Bernien
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Danny Thonig
- Department of Physics and Astronomy, Materials Theory , Uppsala University , SE-75120 Uppsala , Sweden
| | - Anna Delin
- Department of Physics and Astronomy, Materials Theory , Uppsala University , SE-75120 Uppsala , Sweden
- Department of Applied Physics, School of Engineering Sciences , KTH Royal Institute of Technology , Electrum 229 , SE-16440 Kista , Sweden
- SeRC (Swedish e-Science Research Center), KTH Royal Institute of Technology , SE-10044 Stockholm , Sweden
| | - Jonas Fransson
- Department of Physics and Astronomy, Materials Theory , Uppsala University , SE-75120 Uppsala , Sweden
| | - Kurt Kummer
- European Synchrotron Radiation Facility , 71 Avenue des Martyrs, CS40220 , F-38043 Grenoble , Cedex 9, France
| | - Nicholas B Brookes
- European Synchrotron Radiation Facility , 71 Avenue des Martyrs, CS40220 , F-38043 Grenoble , Cedex 9, France
| | - Olle Eriksson
- Department of Physics and Astronomy, Materials Theory , Uppsala University , SE-75120 Uppsala , Sweden
- School of Science and Technology , Örebro University , SE-701 82 Örebro , Sweden
| | - Wolfgang Kuch
- Institut für Experimentalphysik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Thomas Michely
- II. Physikalisches Institut , Universität zu Köln , Zülpicher Strasse 77 , D-50937 Köln , Germany
| | - Heiko Wende
- Fakultät für Physik , Universität Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) , Lotharstr. 1 , D-47057 Duisburg , Germany
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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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Interfacial Spin Manipulation of Nickel-Quinonoid Complex Adsorbed on Co(001) Substrate. MAGNETOCHEMISTRY 2018. [DOI: 10.3390/magnetochemistry5010002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We studied the structural, electronic, and magnetic properties of a recently synthesized Ni(II)-quinonoid complex upon adsorption on a magnetic Co(001) substrate. Our density functional theory + U (DFT+U) calculations predict that the molecule undergoes a spin-state switching from low-spin S = 0 in the gas phase to high-spin S ≈ 1 when adsorbed on the Co(001) surface. A strong covalent interaction of the quinonoid rings and surface atoms leads to an increase of the Ni–O(N) bond lengths in the chemisorbed molecule that support the spin-state switching. Our DFT+U calculations show that the molecule is ferromagnetically coupled to the substrate. The Co surface–Ni center exchange mechanism was carefully investigated. We identified an indirect exchange interaction via the quinonoid ligands that stabilizes the molecule’s spin moment in ferromagnetic alignment with the Co surface magnetization.
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Hötger D, Abufager P, Morchutt C, Alexa P, Grumelli D, Dreiser J, Stepanow S, Gambardella P, Busnengo HF, Etzkorn M, Gutzler R, Kern K. On-surface transmetalation of metalloporphyrins. NANOSCALE 2018; 10:21116-21122. [PMID: 30406233 DOI: 10.1039/c8nr04786c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Increasing the complexity of 2D metal-organic networks has led to the fabrication of structures with interesting magnetic and catalytic properties. However, increasing complexity by providing different coordination environments for different metal types imposes limitations on their synthesis if the controlled placement of one metal type into one coordination environment is desired. Whereas metal insertion into free-base porphyrins at the vacuum/solid interface has been thoroughly studied, providing detailed insight into the mechanisms at play, the chemical interaction of a metal atom with a metallated porphyrin is rarely investigated. Herein, the breadth of metalation reactions is augmented towards the metal exchange of a metalloporphyrin through the deliberate addition of atomic metal centers. The cation of Fe(ii)-tetraphenylporphyrins can be replaced by Co in a redox transmetalation-like reaction on a Au(111) surface. Likewise, Cu can be replaced by Co. The reverse reaction does not occur, i.e. Fe does not replace Co in the porphyrin. This non-reversible exchange is investigated in detail by X-ray absorption spectroscopy complemented by scanning tunneling microscopy. Density functional theory illuminates possible reaction pathways and leads to the conclusion that the transmetalation proceeds through the adsorption of initially metallic (neutral) Co onto the porphyrin and the expulsion of Fe towards the surface accompanied by Co insertion. Our findings have important implications for the fabrication of porphyrin layers on surfaces when subject to the additional deposition of metals. Mixed-metal porphyrin layers can be fabricated by design in a solvent-free process, but conversely care must be taken that the transmetalation does not proceed as an undesired side reaction.
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Affiliation(s)
- Diana Hötger
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany.
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Nachtigallová D, Antalík A, Lo R, Sedlák R, Manna D, Tuček J, Ugolotti J, Veis L, Legeza Ö, Pittner J, Zbořil R, Hobza P. An Isolated Molecule of Iron(II) Phthalocyanin Exhibits Quintet Ground-State: A Nexus between Theory and Experiment. Chemistry 2018; 24:13413-13417. [DOI: 10.1002/chem.201803380] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 07/31/2018] [Indexed: 01/07/2023]
Affiliation(s)
- Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Andrej Antalík
- J. Heyrovský Institute of Physical Chemistry; Academy of Sciences of the Czech Republic; v.v.i., Dolejškova 3 18223 Prague 8 Czech Republic
- Faculty of Mathematics and Physics; Charles University Prague; 11636 Prague Czech Republic Republic
| | - Rabindranath Lo
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Robert Sedlák
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Debashree Manna
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Jiří Tuček
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Juri Ugolotti
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Libor Veis
- J. Heyrovský Institute of Physical Chemistry; Academy of Sciences of the Czech Republic; v.v.i., Dolejškova 3 18223 Prague 8 Czech Republic
| | - Örs Legeza
- Strongly Correlated Systems “ Lendület” Research group; Wigner Research Centre for Physics; 1525 Budapest Hungary
| | - Jiří Pittner
- J. Heyrovský Institute of Physical Chemistry; Academy of Sciences of the Czech Republic; v.v.i., Dolejškova 3 18223 Prague 8 Czech Republic
| | - Radek Zbořil
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Pavel Hobza
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science, Palacký University in Olomouc; Šlechtitelů 27 78371 Olomouc Czech Republic
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Wang X, Yang L, Ye L, Zheng X, Yan Y. Precise Control of Local Spin States in an Adsorbed Magnetic Molecule with an STM Tip: Theoretical Insights from First-Principles-Based Simulation. J Phys Chem Lett 2018; 9:2418-2425. [PMID: 29685031 DOI: 10.1021/acs.jpclett.8b00808] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The precise tuning of local spin states in adsorbed organometallic molecules by a mechanically controlled scanning tunneling microscope (STM) tip has become a focus of recent experiments. However, the underlying mechanisms remain somewhat unclear. We investigate theoretically the STM tip control of local spin states in a single iron(II) porphyrin molecule adsorbed on the Pb(111) substrate. A combined density functional theory and hierarchical equations of motion approach is employed to simulate the tip tuning process in conjunction with the complete active space self-consistent field method for accurate computation of magnetic anisotropy. Our first-principles-based simulation accurately reproduces the tuning of magnetic anisotropy realized in experiment. Moreover, we elucidate the evolution of geometric and electronic structures of the composite junction and disclose the delicate competition between the Kondo resonance and local spin excitation. The understanding and insight provided by the first-principles-based simulation may help to realize more fascinating quantum state manipulations.
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Affiliation(s)
- Xiaoli Wang
- Hefei National Laboratory for Physical Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Longqing Yang
- Hefei National Laboratory for Physical Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - LvZhou Ye
- Hefei National Laboratory for Physical Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Xiao Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Institute of Applied Physics , Guizhou Normal College , Guiyang , Guizhou 550018 , China
| | - YiJing Yan
- Hefei National Laboratory for Physical Sciences at the Microscale & iChEM , University of Science and Technology of China , Hefei , Anhui 230026 , China
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Avvisati G, Cardoso C, Varsano D, Ferretti A, Gargiani P, Betti MG. Ferromagnetic and Antiferromagnetic Coupling of Spin Molecular Interfaces with High Thermal Stability. NANO LETTERS 2018; 18:2268-2273. [PMID: 29558616 DOI: 10.1021/acs.nanolett.7b04836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report an advanced organic spin-interface architecture with magnetic remanence at room temperature, constituted by metal phthalocyanine molecules magnetically coupled with Co layer(s), mediated by graphene. Fe- and Cu-phthalocyanines assembled on graphene/Co have identical structural configurations, but FePc couples antiferromagnetically with Co up to room temperature, while CuPc couples ferromagnetically with weaker coupling and thermal stability, as deduced by element-selective X-ray magnetic circular dichroic signals. The robust antiferromagnetic coupling is stabilized by a superexchange interaction, driven by the out-of-plane molecular orbitals responsible of the magnetic ground state and electronically decoupled from the underlying metal via the graphene layer, as confirmed by ab initio theoretical predictions. These archetypal spin interfaces can be prototypes to demonstrate how antiferromagnetic and/or ferromagnetic coupling can be optimized by selecting the molecular orbital symmetry.
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Affiliation(s)
- Giulia Avvisati
- Dipartimento di Fisica , Università di Roma "La Sapienza" , I-00185 Roma , Italy
| | - Claudia Cardoso
- Centro S3 , CNR-Istituto Nanoscienze , I-41125 Modena , Italy
| | - Daniele Varsano
- Centro S3 , CNR-Istituto Nanoscienze , I-41125 Modena , Italy
| | - Andrea Ferretti
- Centro S3 , CNR-Istituto Nanoscienze , I-41125 Modena , Italy
| | - Pierluigi Gargiani
- ALBA Synchrotron Light Source, E-08290 Cerdanyola del Valles, Barcelona , Spain
| | - Maria Grazia Betti
- Dipartimento di Fisica , Università di Roma "La Sapienza" , I-00185 Roma , Italy
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20
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Huang Z, Zhang Y, He Y, Song H, Yin C, Wu K. A chemist's overview of surface electron spins. Chem Soc Rev 2018; 46:1955-1976. [PMID: 28317957 DOI: 10.1039/c6cs00891g] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review summarizes recent research progress in the measurement and tuning of the electron spins of alien atoms and molecules adsorbed on well-defined substrates. After a brief introduction to the main experimental techniques employed to study surface electron spins, some well-explored systems consisting of atomic and molecular spin-carriers at surfaces are overviewed from a chemist's viewpoint, focusing on the experimental measurements and chemical modifications of the electron spin states of the alien entities at the surfaces on the atomic/molecular level. Finally, personal perspectives have been provided, aiming at describing some of the remaining issues that need to be addressed in the future and proposing potential applications in surface chemistry.
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Affiliation(s)
- Zhichao Huang
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Yajie Zhang
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Yang He
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Huanjun Song
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Cen Yin
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Kai Wu
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
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21
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Controlled spin switching in a metallocene molecular junction. Nat Commun 2017; 8:1974. [PMID: 29215014 PMCID: PMC5719446 DOI: 10.1038/s41467-017-02151-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 11/09/2017] [Indexed: 12/01/2022] Open
Abstract
The active control of a molecular spin represents one of the main challenges in molecular spintronics. Up to now spin manipulation has been achieved through the modification of the molecular structure either by chemical doping or by external stimuli. However, the spin of a molecule adsorbed on a surface depends primarily on the interaction between its localized orbitals and the electronic states of the substrate. Here we change the effective spin of a single molecule by modifying the molecule/metal interface in a controlled way using a low-temperature scanning tunneling microscope. A nickelocene molecule reversibly switches from a spin 1 to 1/2 when varying the electrode–electrode distance from tunnel to contact regime. This switching is experimentally evidenced by inelastic and elastic spin-flip mechanisms observed in reproducible conductance measurements and understood using first principle calculations. Our work demonstrates the active control over the spin state of single molecule devices through interface manipulation. Manipulating spin states of molecules in a controllable manner is essential to develop the molecule-based spintronics technologies. Here, Ormaza et al. show how to use the interaction between a single metallocene molecule and a metallic surface to reversibly switch spin from 1 to ½ in a junction.
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22
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Zhao XX, Chen HQ, Li B. First-Principles Study on Magnetism of Manganese Dithiolene-diamine and Dihydroxyl-diamine Nanosheets. CHINESE J CHEM PHYS 2017. [DOI: 10.1063/1674-0068/30/cjcp1705085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xiao-xia Zhao
- Department of Physics, University of Science and Technology of China, Hefei 230026, China
| | - Hao-qi Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Bin Li
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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23
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Miralles SG, Bedoya-Pinto A, Baldoví JJ, Cañon-Mancisidor W, Prado Y, Prima-Garcia H, Gaita-Ariño A, Mínguez Espallargas G, Hueso LE, Coronado E. Sublimable chloroquinolinate lanthanoid single-ion magnets deposited on ferromagnetic electrodes. Chem Sci 2017; 9:199-208. [PMID: 29629088 PMCID: PMC5869315 DOI: 10.1039/c7sc03463f] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/17/2017] [Indexed: 01/17/2023] Open
Abstract
A new family of chloroquinolinate lanthanoid complexes of the formula A+[Ln(5,7Cl2q)4]-, with Ln = Y3+, Tb3+ and Dy3+ and A+ = Na+, NEt4+ and K0.5(NEt4)0.5+, is studied, both in bulk and as thin films. Several members of the family are found to present single-molecule magnetic behavior in bulk. Interestingly, the sodium salts can be sublimed under high vacuum conditions retaining their molecular structures and magnetic properties. These thermally stable compounds have been deposited on different substrates (Al2O3, Au and NiFe). The magnetic properties of these molecular films show the appearance of cusps in the zero-field cooled curves when they are deposited on permalloy (NiFe). This indicates a magnetic blocking caused by the interaction between the single-ion magnet and the ferromagnet. X-ray absorption spectroscopy confirms the formation of hybrid states at the molecule/metal interface.
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Affiliation(s)
- Sara G Miralles
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
| | - Amilcar Bedoya-Pinto
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastián , Spain . .,Max-Planck Institute of Microstructure Physics , Weinberg 2 , 06120 Halle , Germany
| | - José J Baldoví
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain . .,Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , D-22761 Hamburg , Germany
| | - Walter Cañon-Mancisidor
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain . .,Facultad de Química y Biologia , Depto. de Química de los Materiales , Universidad de Santiago de Chile , USACH , Chile
| | - Yoann Prado
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
| | - Helena Prima-Garcia
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
| | - Alejandro Gaita-Ariño
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
| | - Guillermo Mínguez Espallargas
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
| | - Luis E Hueso
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastián , Spain .
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , Catedrático José Beltrán 2, 46980 Paterna , Valencia , Spain .
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Wang Y, Li X, Zheng X, Yang J. Spin switch in iron phthalocyanine on Au(111) surface by hydrogen adsorption. J Chem Phys 2017; 147:134701. [PMID: 28987089 DOI: 10.1063/1.4996970] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The manipulation of spin states at the molecular scale is of fundamental importance for the development of molecular spintronic devices. One of the feasible approaches for the modification of a molecular spin state is through the adsorption of certain specific atoms or molecules including H, NO, CO, NH3, and O2. In this paper, we demonstrate that the local spin state of an individual iron phthalocyanine (FePc) molecule adsorbed on an Au(111) surface exhibits controllable switching by hydrogen adsorption, as evidenced by using first-principles calculations based on density functional theory. Our theoretical calculations indicate that different numbers of hydrogen adsorbed at the pyridinic N sites of the FePc molecule largely modify the structural and electronic properties of the FePc/Au(111) composite by forming extra N-H bonds. In particular, the adsorption of one or up to three hydrogen atoms induces a redistribution of charge (spin) density within the FePc molecule, and hence a switching to a low spin state (S = 1/2) from an intermediate spin state (S = 1) is achieved, while the adsorption of four hydrogen atoms distorts the molecular conformation by increasing Fe-N bond lengths in FePc and thus breaks the ligand field exerted on the Fe 3d orbitals via stronger hybridization with the substrate, leading to an opposite switching to a high-spin state (S = 2). These findings obtained from the theoretical simulations could be useful for experimental manipulation or design of single-molecule spintronic devices.
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Affiliation(s)
- Yu Wang
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Xiaoguang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Xiao Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jinlong Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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25
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Smykalla L, Mende C, Fronk M, Siles PF, Hietschold M, Salvan G, Zahn DRT, Schmidt OG, Rüffer T, Lang H. (Metallo)porphyrins for potential materials science applications. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:1786-1800. [PMID: 28904840 PMCID: PMC5588670 DOI: 10.3762/bjnano.8.180] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 07/16/2017] [Indexed: 06/07/2023]
Abstract
The bottom-up approach to replace existing devices by molecular-based systems is a subject that attracts permanently increasing interest. Molecular-based devices offer not only to miniaturize the device further, but also to benefit from advanced functionalities of deposited molecules. Furthermore, the molecules itself can be tailored to allow via their self-assembly the potential fabrication of devices with an application potential, which is still unforeseeable at this time. Herein, we review efforts to use discrete (metallo)porphyrins for the formation of (sub)monolayers by surface-confined polymerization, of monolayers formed by supramolecular recognition and of thin films formed by sublimation techniques. Selected physical properties of these systems are reported as well. The application potential of those ensembles of (metallo)porphyrins in materials science is discussed.
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Affiliation(s)
- Lars Smykalla
- Solid Surfaces Analysis Group, Institute of Physics, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Carola Mende
- Inorganic Chemistry, Institute of Chemistry, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Michael Fronk
- Semiconductor Physics, Institute of Physics, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Pablo F Siles
- Material Systems for Nanoelectronics, TU Chemnitz, D-09107 Chemnitz, Germany
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Michael Hietschold
- Solid Surfaces Analysis Group, Institute of Physics, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Georgeta Salvan
- Semiconductor Physics, Institute of Physics, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Dietrich R T Zahn
- Semiconductor Physics, Institute of Physics, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Oliver G Schmidt
- Material Systems for Nanoelectronics, TU Chemnitz, D-09107 Chemnitz, Germany
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Tobias Rüffer
- Inorganic Chemistry, Institute of Chemistry, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
| | - Heinrich Lang
- Inorganic Chemistry, Institute of Chemistry, Faculty of Natural Sciences, TU Chemnitz, D-09107 Chemnitz, Germany
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26
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Wang A, Zhang X, Feng Y, Zhao M. Chern Insulator and Chern Half-Metal States in the Two-Dimensional Spin-Gapless Semiconductor Mn 2C 6S 12. J Phys Chem Lett 2017; 8:3770-3775. [PMID: 28762733 DOI: 10.1021/acs.jpclett.7b01187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Two-dimensional metal-organic frameworks (2D-MOFs) with exotic electronic structures are drawing increasing attention. Here, using first-principles calculations, we demonstrate a spin-gapless MOF, namely, Mn2C6S12, with the coexistence of a spin-polarized Dirac cone and parabolic degenerate points. The Curie temperature evaluated from Monte Carlo simulations implies Mn2C6S12 possessing stable ferromagnetism at room temperature. Taking the spin-orbit coupling into account, the Dirac cone is gapped and the degenerate points are lifted, giving rise to multiple topologically nontrivial states with nonzero Chern number, which imply the possibility of Mn2C6S12 to be a Chern insulator and a Chern half-metal. Our results offer versatile platforms for achieving spin filtering or a quantum anomalous Hall effect with promising application in spintronics devices.
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Affiliation(s)
- Aizhu Wang
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University , Jinan 250100, Shandong, China
- Department of Electrical and Computer Engineering and Department of Physics, National University of Singapore , Singapore 117579, Singapore
| | - Xiaoming Zhang
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University , Jinan 250100, Shandong, China
| | - Yuanping Feng
- Department of Physics & Centre for Advanced Two-Dimensional Materials, National University of Singapore , Singapore 117542, Singapore
| | - Mingwen Zhao
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University , Jinan 250100, Shandong, China
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27
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Li W, Sun L, Qi J, Jarillo-Herrero P, Dincă M, Li J. High temperature ferromagnetism in π-conjugated two-dimensional metal-organic frameworks. Chem Sci 2017; 8:2859-2867. [PMID: 28553524 PMCID: PMC5428024 DOI: 10.1039/c6sc05080h] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/20/2017] [Indexed: 11/21/2022] Open
Abstract
We use first-principles calculations to show that the square symmetry of two-dimensional (2D) metal-organic frameworks (MOFs) made from octaamino-substituted phthalocyanines and square planar Ni2+ ions, which enable strong conjugation of π electrons, has a critical impact on the magnetic properties of the lattice. In particular, we predict the unexpected emergence of a rare high-temperature ferromagnetic half-metallic ground state in one case. Among charge neutral MOFs made from (2,3,9,10,16,17,23,24)-octaiminophthalocyanine (OIPc) metallated with divalent first-row transition metal ions (M-OIPc; M = Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+) and connected through square planar Ni-bisphenylenediimine moieties, NiMn-OIPc exhibits a half-metallic and ferromagnetic ground state with a large exchange energy resulting from the unique strong hybridization between the d/π orbitals of Mn, the Pc ring, and the Ni-bisphenylenediimine nodes. Notably, we show that for NiMn-OIPc there is a considerable difference between the ferromagnetic ordering temperature (Tc) predicted by a 2D Ising model, which exceeds 600 K, and a Tc of 170 K predicted by our more realistic Monte Carlo simulation that includes magnetic anisotropy. Critically, our simulations adopt two spin models that incorporate magnetic anisotropy in the form of exchange anisotropy and single-ion anisotropy. We further show that in the bulk, 2D layers of NiMn-OIPc adopt a slipped-parallel stacking configuration, and exhibit interlayer magnetic coupling that is sensitive to the relative in-plane displacement between adjacent layers. These results highlight the critical role of magnetic anisotropy in modeling the properties of 2D magnetic systems. More generally, it demonstrates that strong hybridization between open-shell ions and delocalized aromatic π systems with appropriate symmetry, combined with large magnetic anisotropy, will be an effective design strategy to realize ferromagnetic 2D MOFs with high Tc.
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Affiliation(s)
- Wenbin Li
- Research Laboratory of Electronics , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA
| | - Lei Sun
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA .
| | - Jingshan Qi
- Department of Nuclear Science and Engineering , Department of Materials Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA .
| | - Pablo Jarillo-Herrero
- Department of Physics , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA
| | - Mircea Dincă
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA .
| | - Ju Li
- Department of Nuclear Science and Engineering , Department of Materials Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA .
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28
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Gruber M, Miyamachi T, Davesne V, Bowen M, Boukari S, Wulfhekel W, Alouani M, Beaurepaire E. Spin crossover in Fe(phen)2(NCS)2 complexes on metallic surfaces. J Chem Phys 2017. [DOI: 10.1063/1.4973511] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Toshio Miyamachi
- The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - Vincent Davesne
- Laboratoire de Chimie de Coordination, 205 Route de Narbonne, 31077 Cedex 04 Toulouse, France
| | - Martin Bowen
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, BP 43, 67034 Cedex 2 Strasbourg, France
| | - Samy Boukari
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, BP 43, 67034 Cedex 2 Strasbourg, France
| | - Wulf Wulfhekel
- Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Mebarek Alouani
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, BP 43, 67034 Cedex 2 Strasbourg, France
| | - Eric Beaurepaire
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, BP 43, 67034 Cedex 2 Strasbourg, France
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29
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Kuch W, Bernien M. Controlling the magnetism of adsorbed metal-organic molecules. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:023001. [PMID: 27841987 DOI: 10.1088/0953-8984/29/2/023001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Gaining control on the size or the direction of the magnetic moment of adsorbed metal-organic molecules constitutes an important step towards the realization of a surface-mounted molecular spin electronics. Such control can be gained by taking advantage of interactions of the molecule's magnetic moment with the environment. The paramagnetic moments of adsorbed metal-organic molecules, for example, can be controlled by the interaction with magnetically ordered substrates. Metalloporphyrins and -phthalocyanines display a quasi-planar geometry, allowing the central metal ion to interact with substrate electronic states. This can lead to magnetic coupling with a ferromagnetic or even antiferromagnetic substrate. The molecule-substrate coupling can be mediated and controlled by insertion layers such as oxygen atoms, graphene, or nonmagnetic metal layers. Control on the magnetic properties of adsorbed metalloporphyrins or -phthalocyanines can also be gained by on-surface chemical modification of the molecules. The magnetic moment or the magnetic coupling to ferromagnetic substrates can be changed by adsorption and thermal desorption of small molecules that interact with the fourfold-coordinated metal center via the remaining axial coordination site. Spin-crossover molecules, which possess a metastable spin state that can be switched by external stimuli such as temperature or light, are another promising class of candidates for control of magnetic properties. However, the immobilization of such molecules on a solid surface often results in a quench of the spin transition due to the interaction with the substrate. We present examples of Fe(II) spin-crossover complexes in direct contact with a solid surface that undergo a reversible spin-crossover transition as a function of temperature, by illumination with visible light, or can be switched by the tip of a scanning tunneling microscope.
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Affiliation(s)
- Wolfgang Kuch
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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30
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Yang Z, Zhao T, Huang X, Chu X, Tang T, Ju Y, Wang Q, Hou Y, Gao S. Modulating the phases of iron carbide nanoparticles: from a perspective of interfering with the carbon penetration of Fe@Fe 3O 4 by selectively adsorbed halide ions. Chem Sci 2017; 8:473-481. [PMID: 28451194 PMCID: PMC5298209 DOI: 10.1039/c6sc01819j] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/13/2016] [Indexed: 11/21/2022] Open
Abstract
Iron carbide nanoparticles (ICNPs) are considered to have great potential in new energy conversion, nanomagnets and biomedical applications due to their intrinsically peculiar magnetic and catalytic properties. However, the synthetic routes were greatly limited in morphology and phase controlled synthesis. In this article, we present a versatile solution chemistry route towards colloidal ICNPs (Fe2C-hexagonal and monoclinic syngony, Fe5C2-monoclinic syngony and Fe3C-orthorhombic syngony) derived from body centered cubic Fe@Fe3O4 by introducing heteroatoms to restrain their phase transformation. We found that the phases of Fe2C NPs could be controlled by direct phase transformation in the drastic thermally driven procedure (defined as thermodynamical manner). Meanwhile, the selective adsorption of Cl ions weakened the bonding between Fe and C atoms, thus interfering with the penetration of C atoms to form lower carbon content Fe5C2 and Fe3C NPs. The kinetic mechanisms were evaluated using density functional theory (DFT) simulations focusing on the bonding energy between Fe-C and Fe-Cl atoms. All the obtained ICNPs exhibited typically soft ferromagnetic properties with the highest saturation magnetization value of 101.2 emu g-1 and the highest Curie temperature of 497.8 K.
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Affiliation(s)
- Ziyu Yang
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Tianshan Zhao
- Center for Applied Physics and Technology , College of Engineering , Peking University , Beijing 100871 , China
| | - Xiaoxiao Huang
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Xin Chu
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Tianyu Tang
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Yanmin Ju
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Qian Wang
- Center for Applied Physics and Technology , College of Engineering , Peking University , Beijing 100871 , China
| | - Yanglong Hou
- Department of Materials Science and Engineering , College of Engineering , Peking University , Beijing 100871 , China .
| | - Song Gao
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
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31
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Droghetti A, Thielen P, Rungger I, Haag N, Großmann N, Stöckl J, Stadtmüller B, Aeschlimann M, Sanvito S, Cinchetti M. Dynamic spin filtering at the Co/Alq3 interface mediated by weakly coupled second layer molecules. Nat Commun 2016; 7:12668. [PMID: 27578395 PMCID: PMC5013676 DOI: 10.1038/ncomms12668] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 07/21/2016] [Indexed: 11/09/2022] Open
Abstract
Spin filtering at organic-metal interfaces is often determined by the details of the interaction between the organic molecules and the inorganic magnets used as electrodes. Here we demonstrate a spin-filtering mechanism based on the dynamical spin relaxation of the long-living interface states formed by the magnet and weakly physisorbed molecules. We investigate the case of Alq3 on Co and, by combining two-photon photoemission experiments with electronic structure theory, show that the observed long-time spin-dependent electron dynamics is driven by molecules in the second organic layer. The interface states formed by physisorbed molecules are not spin-split, but acquire a spin-dependent lifetime, that is the result of dynamical spin-relaxation driven by the interaction with the Co substrate. Such spin-filtering mechanism has an important role in the injection of spin-polarized carriers across the interface and their successive hopping diffusion into successive molecular layers of molecular spintronics devices.
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Affiliation(s)
- Andrea Droghetti
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland.,Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del Pais Vasco CFM, CSIC-UPV/EHU-MPC &DIPC, Avenue Tolosa 72, 20018 San Sebastian, Spain
| | - Philip Thielen
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany.,Graduate School of Excellence Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, 67663 Kaiserslautern, Germany
| | - Ivan Rungger
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland.,National Physical Laboratory, Teddington TW11 0LW, UK
| | - Norman Haag
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany
| | - Nicolas Großmann
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany
| | - Johannes Stöckl
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany
| | - Benjamin Stadtmüller
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany.,Graduate School of Excellence Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, 67663 Kaiserslautern, Germany
| | - Martin Aeschlimann
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany
| | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | - Mirko Cinchetti
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger Strasse 46, 67663 Kaiserslautern, Germany
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32
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Choudhuri I, Kumar S, Mahata A, Rawat KS, Pathak B. Transition-metal embedded carbon nitride monolayers: high-temperature ferromagnetism and half-metallicity. NANOSCALE 2016; 8:14117-14126. [PMID: 27321785 DOI: 10.1039/c6nr03282f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
High-temperature ferromagnetic materials with planar surfaces are promising candidates for spintronics applications. Using state-of-the-art density functional theory (DFT) calculations, transition metal (TM = Cr, Mn, and Fe) incorporated graphitic carbon nitride (TM@gt-C3N4) systems are investigated as possible spintronics devices. Interestingly, ferromagnetism and half-metallicity were observed in all of the TM@gt-C3N4 systems. We find that Cr@gt-C3N4 is a nearly half-metallic ferromagnetic material with a Curie temperature of ∼450 K. The calculated Curie temperature is noticeably higher than other planar 2D materials studied to date. Furthermore, it has a steel-like mechanical stability and also possesses remarkable dynamic and thermal (500 K) stability. The calculated magnetic anisotropy energy (MAE) in Cr@gt-C3N4 is as high as 137.26 μeV per Cr. Thereby, such material with a high Curie temperature can be operated at high temperatures for spintronics devices.
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Affiliation(s)
- Indrani Choudhuri
- Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology (IIT) Indore, Indore, M.P. 452020, India
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33
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Salazar C, Lach J, Rückerl F, Baumann D, Schimmel S, Knupfer M, Kersting B, Büchner B, Hess C. STM Study of Au(111) Surface-Grafted Paramagnetic Macrocyclic Complexes [Ni2L(Hmba)](+) via Ambidentate Coligands. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4464-4471. [PMID: 27093097 DOI: 10.1021/acs.langmuir.6b00772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Molecular anchoring and electronic properties of macrocyclic complexes fixed on gold surfaces have been investigated mainly by using scanning tunnelling microscopy (STM) and complemented with X-ray photoelectron spectroscopy (XPS). Exchange-coupled macrocyclic complexes [Ni2L(Hmba)](+) were deposited via 4-mercaptobenzoate ligands on the surface of a Au(111) single crystal from a mM solution of the perchlorate salt [Ni2L(Hmba)]ClO4 in dichloromethane. The combined results from STM and XPS show the formation of large monolayers anchored via Au-S bonds with a height of about 1.5 nm. Two apparent granular structures are visible: one related to the dinickel molecular complexes (cationic structures) and a second one related to the counterions ClO4(-) which stabilize the monolayer. No type of short and long-range order is observed. STM tip-interaction with the monolayer reveals higher degradation after 8 h of measurement. Spectroscopy measurements suggest a gap of about 2.5 eV between HOMO and LUMO of the cationic structures and smaller gap in the areas related to the anionic structures.
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Affiliation(s)
- Christian Salazar
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
| | - Jochen Lach
- Institut für Anorganische Chemie, Universität Leipzig , 04103 Leipzig, Germany
| | - Florian Rückerl
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
| | - Danny Baumann
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
| | - Sebastian Schimmel
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
| | - Martin Knupfer
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
| | - Berthold Kersting
- Institut für Anorganische Chemie, Universität Leipzig , 04103 Leipzig, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
- Center for Transport and Devices, Technische Universität Dresden , 01069 Dresden, Germany
| | - Christian Hess
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden) , Helmholtzstrasse 20, 01171 Dresden, Germany
- Center for Transport and Devices, Technische Universität Dresden , 01069 Dresden, Germany
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34
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Jiang W, Zhou M, Liu Z, Sun D, Vardeny ZV, Liu F. Structural, electronic, and magnetic properties of tris(8-hydroxyquinoline)iron(III) molecules and their magnetic coupling with ferromagnetic surface: first-principles study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:176004. [PMID: 27044670 DOI: 10.1088/0953-8984/28/17/176004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using first-principles calculations, we have systematically investigated the structural, electronic, and magnetic properties of facial (fac-) and meridional (mer-) tris(8-hydroxyquinoline)iron(III) (Feq3) molecules and their interaction with ferromagnetic substrate. Our calculation results show that for the isolated Feq3, mer-Feq3 is more stable than the fac-Feq3; both Feq3 isomers have a high spin-state of 5 μB as the ground state when an on-site Hubbard-U term is included to treat the highly localized Fe 3d electrons; while the standard DFT calculations produce a low spin-state of 1 μB for mer-Feq3. These magnetic behaviors can be understood by the octahedral ligand field splitting theory. Furthermore, we found that fac-Feq3 has a stronger bonding to the Co surface than mer-Feq3 and an anti-ferromagnetic coupling was discovered between Fe and Co substrate, originating from the superexchange coupling between Fe and Co mediated by the interface oxygen and nitrogen atoms. These findings suggest that Feq3 molecular films may serve as a promising spin-filter material in spintronic devices.
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Affiliation(s)
- W Jiang
- Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112, USA
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35
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Gueddida S, Gruber M, Miyamachi T, Beaurepaire E, Wulfhekel W, Alouani M. Exchange Coupling of Spin-Crossover Molecules to Ferromagnetic Co Islands. J Phys Chem Lett 2016; 7:900-904. [PMID: 26895075 DOI: 10.1021/acs.jpclett.6b00172] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The properties of Fe(1,10-phenanthroline)2(NCS)2 (Fe-phen) molecules deposited on Co/Cu(111) are studied with scanning tunneling microscopy (STM) operated in ultrahigh vacuum at low temperature (4 K) and ab initio calculations. Both the experimental and theoretical results are used to identify the high-spin (HS) state of Fe-phen. Additionally, the calculations reveal a strong spin-polarization of the density of states (DOS) and is validated experimentally using the spin sensitivity of spin-polarized STM. Finally, it is shown that the magnetic moment of the Fe-ion within HS Fe-phen is strongly magnetically coupled to the underlying magnetic Co through the NCS groups. These findings enable promising spintronic perspectives.
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Affiliation(s)
- Saber Gueddida
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Manuel Gruber
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), 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
| | - Toshio Miyamachi
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Eric Beaurepaire
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg, CNRS UMR 7504 , 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
| | - Wulf Wulfhekel
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
| | - Mebarek Alouani
- Physikalisches Institut, Karlsruhe Institute of Technology , Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
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36
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Candini A, Klar D, Marocchi S, Corradini V, Biagi R, De Renzi V, Del Pennino U, Troiani F, Bellini V, Klyatskaya S, Ruben M, Kummer K, Brookes NB, Huang H, Soncini A, Wende H, Affronte M. Spin-communication channels between Ln(III) bis-phthalocyanines molecular nanomagnets and a magnetic substrate. Sci Rep 2016; 6:21740. [PMID: 26907811 PMCID: PMC4764849 DOI: 10.1038/srep21740] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/25/2016] [Indexed: 12/03/2022] Open
Abstract
Learning the art of exploiting the interplay between different units at the atomic scale is a fundamental step in the realization of functional nano-architectures and interfaces. In this context, understanding and controlling the magnetic coupling between molecular centers and their environment is still a challenging task. Here we present a combined experimental-theoretical work on the prototypical case of the bis(phthalocyaninato)-lanthanide(III) (LnPc2) molecular nanomagnets magnetically coupled to a Ni substrate. By means of X-ray magnetic circular dichroism we show how the coupling strength can be tuned by changing the Ln ion. The microscopic parameters of the system are determined by ab-initio calculations and then used in a spin Hamiltonian approach to interpret the experimental data. By this combined approach we identify the features of the spin communication channel: the spin path is first realized by the mediation of the external (5d) electrons of the Ln ion, keeping the characteristic features of the inner 4 f orbitals unaffected, then through the organic ligand, acting as a bridge to the external world.
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Affiliation(s)
- A Candini
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy
| | - D Klar
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstraße 1, D-47048 Duisburg, Germany
| | - S Marocchi
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy
| | - V Corradini
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy
| | - R Biagi
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy.,Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia via G. Campi 213/A, 41125 Modena, Italy
| | - V De Renzi
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy.,Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia via G. Campi 213/A, 41125 Modena, Italy
| | - U Del Pennino
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy.,Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia via G. Campi 213/A, 41125 Modena, Italy
| | - F Troiani
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy
| | - V Bellini
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy
| | - S Klyatskaya
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - M Ruben
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany.,Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 UdS-CNRS, 67034 Strasbourg Cedex 2, France
| | - K Kummer
- European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38043 Grenoble, France
| | - N B Brookes
- European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38043 Grenoble, France
| | - H Huang
- School of Chemistry, The University of Melbourne, 3010 Victoria, Australia
| | - A Soncini
- School of Chemistry, The University of Melbourne, 3010 Victoria, Australia
| | - H Wende
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstraße 1, D-47048 Duisburg, Germany
| | - M Affronte
- Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A, 41125 Modena, Italy.,Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia via G. Campi 213/A, 41125 Modena, Italy
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37
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Spin-Hybrids: A Single-Molecule Approach to Spintronics. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2016. [DOI: 10.1380/ejssnt.2016.17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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38
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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 LETTERS 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] [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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Glaser M, Peisert H, Adler H, Aygül U, Ivanovic M, Nagel P, Merz M, Schuppler S, Chassé T. Electronic structure at transition metal phthalocyanine-transition metal oxide interfaces: Cobalt phthalocyanine on epitaxial MnO films. J Chem Phys 2015; 142:101918. [PMID: 25770507 DOI: 10.1063/1.4907899] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The electronic structure of the interface between cobalt phthalocyanine (CoPc) and epitaxially grown manganese oxide (MnO) thin films is studied by means of photoemission (PES) and X-ray absorption spectroscopy (XAS). Our results reveal a flat-lying adsorption geometry of the molecules on the oxide surface which allows a maximal interaction between the π-system and the substrate. A charge transfer from MnO, in particular, to the central metal atom of CoPc is observed by both PES and XAS. The change of the shape of N-K XAS spectra at the interface points, however, to the involvement of the Pc macrocycle in the charge transfer process. As a consequence of the charge transfer, energetic shifts of MnO related core levels were observed, which are discussed in terms of a Fermi level shift in the semiconducting MnO films due to interface charge redistribution.
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Affiliation(s)
- Mathias Glaser
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Heiko Peisert
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Hilmar Adler
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Umut Aygül
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Milutin Ivanovic
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Peter Nagel
- Karlsruher Institut für Technologie, Institut für Festkörperphysik, 76021 Karlsruhe, Germany
| | - Michael Merz
- Karlsruher Institut für Technologie, Institut für Festkörperphysik, 76021 Karlsruhe, Germany
| | - Stefan Schuppler
- Karlsruher Institut für Technologie, Institut für Festkörperphysik, 76021 Karlsruhe, Germany
| | - Thomas Chassé
- Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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40
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Ideal Spintronics in Molecule-Based Novel Organometallic Nanowires. Sci Rep 2015; 5:12772. [PMID: 26239021 PMCID: PMC4523865 DOI: 10.1038/srep12772] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/09/2015] [Indexed: 01/11/2023] Open
Abstract
With the purpose of searching for new intriguing nanomaterial for spintronics, a series of novel metalloporphyrin nanowires (M-PPNW, M = Cr, Mn, Fe, Co, Ni, Cu and Zn) and hybrid nanowires fabricated by metalloporphyrin and metal-phthalocyanine (M-PCNW) are systematically investigated by means of first-principles calculations. Our results indicate that the transition metal atoms (TMs) embedded in the frameworks distribute regularly and separately, without any trend to form clusters, thus leading to the ideally ordered spin distribution. Except for the cases embedded with Ni and Zn, the others are spin-polarized. Remarkably, the Mn-PPNW, Mn-PCNW, MnCu-PPNW, MnCr-PCNW, and MnCu-PCNW frameworks all favor the long-ranged ferromagnetic spin ordering and display half-metallic nature, which are of greatest interest and importance for electronics and spintronics. The predicted Curie temperature for the Mn-PCNW is about 150 K. In addition, it is found that the discrepancy in magnetic coupling for these materials is related to the competition mechanisms of through-bond and through-space exchange interactions. In the present work, we propose not only two novel sets of 1D frameworks with appealing magnetic properties, but also a new strategy in obtaining the half-metallic materials by the combination of different neighboring TMs.
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41
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Zhang JL, Wang Z, Zhong JQ, Yuan KD, Shen Q, Xu LL, Niu TC, Gu CD, Wright CA, Tadich A, Qi D, Li HX, Wu K, Xu GQ, Li Z, Chen W. Single-molecule imaging of activated nitrogen adsorption on individual manganese phthalocyanine. NANO LETTERS 2015; 15:3181-3188. [PMID: 25906248 DOI: 10.1021/acs.nanolett.5b00290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An atomic-scale understanding of gas adsorption mechanisms on metal-porphyrins or metal-phthalocyanines is essential for their practical application in biological processes, gas sensing, and catalysis. Intensive research efforts have been devoted to the study of coordinative bonding with relatively active small molecules such as CO, NO, NH3, O2, and H2. However, the binding of single nitrogen atoms has never been addressed, which is both of fundamental interest and indeed essential for revealing the elementary chemical binding mechanism in nitrogen reduction processes. Here, we present a simple model system to investigate, at the single-molecule level, the binding of activated nitrogen species on the single Mn atom contained within the manganese phthalocyanine (MnPc) molecule supported on an inert graphite surface. Through the combination of in situ low-temperature scanning tunneling microscopy, scanning tunneling spectroscopy, ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations, the active site and the binding configuration between the activated nitrogen species (neutral nitrogen atom) and the Mn center of MnPc are investigated at the atomic scale.
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Affiliation(s)
- Jia Lin Zhang
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- ‡Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Zhunzhun Wang
- §Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China
- ⊥Guizhou Provincial Key Laboratory of Computational Nanomaterial Science, Guizhou Normal College, Guiyang 550018, China
| | - Jian Qiang Zhong
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- ‡Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Kai Di Yuan
- ‡Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Qian Shen
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Lei Lei Xu
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Tian Chao Niu
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Cheng Ding Gu
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Christopher A Wright
- ¶Department of Chemistry and Physics, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Anton Tadich
- ¶Department of Chemistry and Physics, La Trobe University, Melbourne, Victoria 3086, Australia
- #Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Dongchen Qi
- ¶Department of Chemistry and Physics, La Trobe University, Melbourne, Victoria 3086, Australia
| | - He Xing Li
- ∥Chinese Education Ministry Key Laboratory of Resource Chemistry, Shanghai Normal University, Shanghai 200234, China
| | - Kai Wu
- ∇Singapore-Peking University Research Center for a Sustainable Low-Carbon Future, 1 CREATE Way, #15-01, CREATE Tower, Singapore 138602, Singapore
- ○College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Guo Qin Xu
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- ∇Singapore-Peking University Research Center for a Sustainable Low-Carbon Future, 1 CREATE Way, #15-01, CREATE Tower, Singapore 138602, Singapore
| | - Zhenyu Li
- §Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Wei Chen
- †Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- ‡Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- ∇Singapore-Peking University Research Center for a Sustainable Low-Carbon Future, 1 CREATE Way, #15-01, CREATE Tower, Singapore 138602, Singapore
- ◆NUS (Suzhou) Research Institute, National University of Singapore, 377 Lin Quan Street, Suzhou Industrial Park, Jiang Su 215123, China
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42
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Abstract
Porphyrins and other tetrapyrrole macrocycles possess an impressive variety of functional properties that have been exploited in natural and artificial systems. Different metal centres incorporated within the tetradentate ligand are key for achieving and regulating vital processes, including reversible axial ligation of adducts, electron transfer, light-harvesting and catalytic transformations. Tailored substituents optimize their performance, dictating their arrangement in specific environments and mediating the assembly of molecular nanoarchitectures. Here we review the current understanding of these species at well-defined interfaces, disclosing exquisite insights into their structural and chemical properties, and also discussing methods by which to manipulate their intramolecular and organizational features. The distinct characteristics arising from the interfacial confinement offer intriguing prospects for molecular science and advanced materials. We assess the role of surface interactions with respect to electronic and physicochemical characteristics, and describe in situ metallation pathways, molecular magnetism, rotation and switching. The engineering of nanostructures, organized layers, interfacial hybrid and bio-inspired systems is also addressed.
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43
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Wang Y, Zhang H, Zhang G, Guo Y. Mechanical and electronic properties of 2D-phthalocyanines under external strain. RSC Adv 2015. [DOI: 10.1039/c5ra20063f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
External strain sparks the localization of π-electrons, leading to the increase of band gaps and effective masses in 2D-phthalocyanines.
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Affiliation(s)
- Yilei Wang
- Department of Life Science
- Heze University
- Heze 274015
- China
| | - Haili Zhang
- Department of Life Science
- Heze University
- Heze 274015
- China
| | - Guisheng Zhang
- Department of Life Science
- Heze University
- Heze 274015
- China
| | - Yanfeng Guo
- Department of Life Science
- Heze University
- Heze 274015
- China
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44
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Wäckerlin C, Donati F, Singha A, Baltic R, Uldry AC, Delley B, Rusponi S, Dreiser J. Strong antiferromagnetic exchange between manganese phthalocyanine and ferromagnetic europium oxide. Chem Commun (Camb) 2015; 51:12958-61. [DOI: 10.1039/c5cc01823d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A record strong antiferromagnetic exchange interaction between an organic magnetic semiconductor and an insulating ferromagnetic oxide is observed.
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Affiliation(s)
- Christian Wäckerlin
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | - Fabio Donati
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | - Aparajita Singha
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | - Romana Baltic
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | | | - Bernard Delley
- Condensed Matter Theory
- Paul Scherrer Institut
- CH-5232 Villigen
- Switzerland
| | - Stefano Rusponi
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | - Jan Dreiser
- Institute of Condensed Matter Physics
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
- Swiss Light Source
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45
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van der Laan G, Figueroa AI. X-ray magnetic circular dichroism—A versatile tool to study magnetism. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.03.018] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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46
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Dreiser J, Wäckerlin C, Ali ME, Piamonteze C, Donati F, Singha A, Pedersen KS, Rusponi S, Bendix J, Oppeneer PM, Jung TA, Brune H. Exchange interaction of strongly anisotropic tripodal erbium single-ion magnets with metallic surfaces. ACS NANO 2014; 8:4662-4671. [PMID: 24645922 DOI: 10.1021/nn500409u] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a comprehensive study of Er(trensal) single-ion magnets deposited in ultrahigh vacuum onto metallic surfaces. X-ray photoelectron spectroscopy reveals that the molecular structure is preserved after sublimation, and that the molecules are physisorbed on Au(111) while they are chemisorbed on a Ni thin film on Cu(100) single-crystalline surfaces. X-ray magnetic circular dichroism (XMCD) measurements performed on Au(111) samples covered with molecular monolayers held at temperatures down to 4 K suggest that the easy axes of the strongly anisotropic molecules are randomly oriented. Furthermore XMCD indicates a weak antiferromagnetic exchange coupling between the single-ion magnets and the ferromagnetic Ni/Cu(100) substrate. For the latter case, spin-Hamiltonian fits to the XMCD M(H) suggest a significant structural distortion of the molecules. Scanning tunneling microscopy reveals that the molecules are mobile on Au(111) at room temperature, whereas they are more strongly attached on Ni/Cu(100). X-ray photoelectron spectroscopy results provide evidence for the chemical bonding between Er(trensal) molecules and the Ni substrate. Density functional theory calculations support these findings and, in addition, reveal the most stable adsorption configuration on Ni/Cu(100) as well as the Ni-Er exchange path. Our study suggests that the magnetic moment of Er(trensal) can be stabilized via suppression of quantum tunneling of magnetization by exchange coupling to the Ni surface atoms. Moreover, it opens up pathways toward optical addressing of surface-deposited single-ion magnets.
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Affiliation(s)
- Jan Dreiser
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
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Girovsky J, Buzzi M, Wäckerlin C, Siewert D, Nowakowski J, Oppeneer PM, Nolting F, Jung TA, Kleibert A, Ballav N. Investigating magneto-chemical interactions at molecule-substrate interfaces by X-ray photo-emission electron microscopy. Chem Commun (Camb) 2014; 50:5190-2. [PMID: 24418897 DOI: 10.1039/c3cc47726f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The magneto-chemical interaction of spin-bearing molecules with substrates is interesting from a coordination chemistry point of view and relevant for spintronics. Unprecedented insight is provided by X-ray photo-emission electron microscopy combined with X-ray magnetic circular dichroism spectroscopy. Here the coupling of a Mn-porphyrin ad-layer to the ferromagnetic Co substrate through suitably modified interfaces is analyzed with this technique.
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Affiliation(s)
- Jan Girovsky
- Laboratory for Micro and Nanotechnology, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
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48
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Zhou J, Sun Q. Carrier induced magnetic coupling transitions in phthalocyanine-based organometallic sheet. NANOSCALE 2014; 6:328-33. [PMID: 24196793 DOI: 10.1039/c3nr04041k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A two-dimensional sheet with long range ferromagnetic (FM) order has been hotly pursued currently. The recent success in synthesizing polymerized Fe-phthalocyanine (poly-FePc) porous sheets paves a possible way to achieve this goal. However, the poly-FePc and its analog poly-CrPc structure are intrinsically antiferromagnetic (AFM). Using first principles combined with Monte-Carlo simulations, we study systematically the carrier-induced magnetic coupling transitions in poly-CrPc and poly-FePc sheets. We show that electron doping can induce stable FM states with Curie temperatures of 130-140 K, while hole doping will enhance the stability of the AFM states. Such changes in magnetic couplings depend on the balance of AFM superexchange and FM p-d exchange.
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Affiliation(s)
- Jian Zhou
- Department of Materials Science and Engineering, Peking University, Beijing 100871, China.
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49
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Klar D, Candini A, Joly L, Klyatskaya S, Krumme B, Ohresser P, Kappler JP, Ruben M, Wende H. Hysteretic behaviour in a vacuum deposited submonolayer of single ion magnets. Dalton Trans 2014; 43:10686-9. [DOI: 10.1039/c4dt01005a] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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50
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Hermanns CF, Bernien M, Krüger A, Schmidt C, Waßerroth ST, Ahmadi G, Heinrich BW, Schneider M, Brouwer PW, Franke KJ, Weschke E, Kuch W. Magnetic coupling of Gd3N@C80 endohedral fullerenes to a substrate. PHYSICAL REVIEW LETTERS 2013; 111:167203. [PMID: 24182296 DOI: 10.1103/physrevlett.111.167203] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Indexed: 06/02/2023]
Abstract
Using magnetic endohedral fullerenes for molecular spintronics requires control over their encapsulated magnetic moments. We show by field-dependent x-ray magnetic circular dichroism measurements of Gd3N@C80 endohedral fullerenes adsorbed on a Cu surface that the magnetic moments of the encapsulated Gd atoms lie in a 4f7 ground state and couple ferromagnetically to each other. When the molecules are in contact with a ferromagnetic Ni substrate, we detect two different Gd species. The more abundant one couples antiferromagnetically to the Ni, whereas the other one exhibits a stronger and ferromagnetic coupling to the substrate. Both of these couplings to the substrate can be explained by an indirect exchange mechanism mediated by the carbon cage. The origin of the distinctly different behavior may be attributed to different orientations and thus electronic coupling of the carbon cage to the substrate, as revealed by scanning tunneling microscopy of the fullerenes on Cu.
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Affiliation(s)
- Christian F Hermanns
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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