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Chiral Magnetic Interactions in Small Fe Clusters Triggered by Symmetry-Breaking Adatoms. Symmetry (Basel) 2023. [DOI: 10.3390/sym15020397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The chirality of the interaction between the local magnetic moments in small transition-metal alloy clusters is investigated in the framework of density-functional theory. The Dzyaloshinskii–Moriya (DM) coupling vectors Dij between the Fe atoms in Fe2X and Fe3X with X = Cu, Pd, Pt, and Ir are derived from independent ground-state energy calculations for different noncollinear orientations of the local magnetic moments. The local-environment dependence of Dij and the resulting relative stability of different chiral magnetic orders are analyzed by contrasting the results for different adatoms X and by systematically varying the distance between the adatom X and the Fe clusters. One observes that the adatoms trigger most significant DM couplings in Fe2X, often in the range of 10–30 meV. Thus, the consequences of breaking the inversion symmetry of the Fe dimer are quantified. Comparison between the symmetric and antisymmetric Fe-Fe couplings shows that the DM couplings are about two orders of magnitude weaker than the isotropic Heisenberg interactions. However, they are in general stronger than the anisotropy of the symmetric couplings. In Fe3X, alloying induces interesting changes in both the direction and strength of the DM couplings, which are the consequence of breaking the reflection symmetry of the Fe trimer and which depend significantly on the adatom-trimer distance. A local analysis of the chirality of the electronic energy shows that the DM interactions are dominated by the spin-orbit coupling at the adatoms and that the contribution of the Fe atoms is small but not negligible.
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Paranthaman S, Vedamanickam N, Ganesan M, Sampathkumar S. Structure, Stability, Electronic and Magnetic Properties of FemBin (m + n = 2–4) Clusters: A DFT Study. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422110279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Structural Disorder and Collective Behavior of Two-Dimensional Magnetic Nanostructures. NANOMATERIALS 2021; 11:nano11061392. [PMID: 34070306 PMCID: PMC8225155 DOI: 10.3390/nano11061392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/13/2022]
Abstract
Structural disorder has been shown to be responsible for profound changes of the interaction-energy landscapes and collective dynamics of two-dimensional (2D) magnetic nanostructures. Weakly-disordered 2D ensembles have a few particularly stable magnetic configurations with large basins of attraction from which the higher-energy metastable configurations are separated by only small downward barriers. In contrast, strongly-disordered ensembles have rough energy landscapes with a large number of low-energy local minima separated by relatively large energy barriers. Consequently, the former show good-structure-seeker behavior with an unhindered relaxation dynamics that is funnelled towards the global minimum, whereas the latter show a time evolution involving multiple time scales and trapping which is reminiscent of glasses. Although these general trends have been clearly established, a detailed assessment of the extent of these effects in specific nanostructure realizations remains elusive. The present study quantifies the disorder-induced changes in the interaction-energy landscape of two-dimensional dipole-coupled magnetic nanoparticles as a function of the magnetic configuration of the ensembles. Representative examples of weakly-disordered square-lattice arrangements, showing good structure-seeker behavior, and of strongly-disordered arrangements, showing spin-glass-like behavior, are considered. The topology of the kinetic networks of metastable magnetic configurations is analyzed. The consequences of disorder on the morphology of the interaction-energy landscapes are revealed by contrasting the corresponding disconnectivity graphs. The correlations between the characteristics of the energy landscapes and the Markovian dynamics of the various magnetic nanostructures are quantified by calculating the field-free relaxation time evolution after either magnetic saturation or thermal quenching and by comparing them with the corresponding averages over a large number of structural arrangements. Common trends and system-specific features are identified and discussed.
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de Oliveira A, Jorge F. Structural, electronic, electrical, and magnetic properties of Rh (1 ≤ n ≤ 13) clusters. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gilmour JTA, Gaston N. On the influence of exact exchange on transition metal superatoms. Phys Chem Chem Phys 2020; 22:772-780. [PMID: 31833486 DOI: 10.1039/c9cp04229f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structure of A7C (A = Hg, Pd, V, Cr, Mn, Fe, Ni, Cu; C = 0, ±1, ±2) clusters has been determined using density functional theory methods. The A7C (A = Hg, Pd, Cr, Cu; C = 0, ±1, ±2) clusters all conform to the existing superatomic model, with a sufficiently stabilised local structure to prevent perturbation upon the introduction of exact exchange to the exchange correlation functional. For the A7C (A = Mn, Fe, Ni; C = 0, ±1, ±2) clusters the incorporation of exact exchange separates the atomic s- and d-electrons, leading to a net increase in the number of superatomic electrons. Conversely the incorporation of exact exchange into the exchange correlation functional decreases the number of superatomic electrons for the V7C (C = 0, ±1, ±2) clusters, owing to the radial extension of the d-orbitals influencing their ability to contribute into superatomic shells.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Berry H, Wang B, Zhang Q. The Behavior of Magnetic Properties in the Clusters of 4d Transition Metals. Molecules 2018; 23:E1896. [PMID: 30060624 PMCID: PMC6222613 DOI: 10.3390/molecules23081896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/23/2018] [Accepted: 07/27/2018] [Indexed: 11/20/2022] Open
Abstract
The current focus of material science researchers is on the magnetic behavior of transition metal clusters due to its great hope for future technological applications. It is common knowledge that the 4d transition elements are not magnetic at their bulk size. However, studies indicate that their magnetic properties are strongly dependent on their cluster sizes. This study attempts to identify magnetic properties of 4d transition metal clusters. Using a tight-binding Friedel model for the density of d-electron states, we investigated the critical size for the magnetic-nonmagnetic transition of 4d transition-metal clusters. Approaching to the critical point, the density of states of the cluster near the Fermi level is higher than 1/J and the discrete energy levels form a quasi-continuous band. Where J is correlation integral. In order to determine the critical size, we considered a square shape band and fcc, bcc, icosahedral and cuboctahedral close-packed structures of the clusters. We also investigated this size dependent magnetic behavior using Heisenberg model. Taking some quantum mechanical approximations in to consideration, we determined magnetic behavior of the clusters. For practicality, we considered three clusters of transition metals (Ru, Rh and Pd) and the obtained results are in line with the results of previous studies.
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Affiliation(s)
- Habte Berry
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
- Department of Physics, College of Natural and Computational Sciences, Dilla University, P.O. Box 419, Dilla, Ethiopia.
| | - Baolin Wang
- School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China.
| | - Qinfang Zhang
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
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Jena P, Sun Q. Super Atomic Clusters: Design Rules and Potential for Building Blocks of Materials. Chem Rev 2018; 118:5755-5870. [DOI: 10.1021/acs.chemrev.7b00524] [Citation(s) in RCA: 302] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Puru Jena
- Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
| | - Qiang Sun
- Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
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Dutta A, Mondal P. Structural evolution, electronic and magnetic manners of small rhodium Rhn+/− (n = 2–8) clusters: a detailed density functional theory study. RSC Adv 2016. [DOI: 10.1039/c5ra21600a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have evaluated the stable electronic structure and magnetic properties of all neutral and ionic Rhn (n = 2–8) clusters using density functional theory. This study reveals that Rh4 is the magic cluster based on the calculated reactivity parameters.
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Affiliation(s)
- Abhijit Dutta
- Department of Chemistry
- Assam University
- Silchar 788011
- India
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Alonso-Lanza T, Ayuela A, Aguilera-Granja F. Chemical Bonding of Transition-Metal Co13Clusters with Graphene. Chemphyschem 2015; 16:3700-10. [DOI: 10.1002/cphc.201500692] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Tomás Alonso-Lanza
- Centro de Física de Materiales CFM-MPC CSIC-UPV/EHU; Donostia International Physics Center (DIPC); Departamento de Física de Materiales; Fac. de Químicas; UPV-EHU; 20018 San Sebastián Spain
| | - Andrés Ayuela
- Centro de Física de Materiales CFM-MPC CSIC-UPV/EHU; Donostia International Physics Center (DIPC); Departamento de Física de Materiales; Fac. de Químicas; UPV-EHU; 20018 San Sebastián Spain
| | - Faustino Aguilera-Granja
- Centro de Física de Materiales CFM-MPC CSIC-UPV/EHU; Donostia International Physics Center (DIPC); Departamento de Física de Materiales; Fac. de Químicas; UPV-EHU; 20018 San Sebastián Spain
- Instituto de Física; Universidad Autónoma de San Luis de Potosí; 78000 San Luis Potosí S.L.P. México
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Jedidi A, Markovits A, Minot C, Abderrabba M, Van Hove MA. CO dissociation on magnetic Fenclusters. Phys Chem Chem Phys 2014; 16:20703-13. [DOI: 10.1039/c4cp01527d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Félix G, Nicolazzi W, Mikolasek M, Molnár G, Bousseksou A. Non-extensivity of thermodynamics at the nanoscale in molecular spin crossover materials: a balance between surface and volume. Phys Chem Chem Phys 2014; 16:7358-67. [DOI: 10.1039/c3cp55031a] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Exploring CO dissociation on Fe nanoparticles by density functional theory-based methods: Fe13 as a case study. Theor Chem Acc 2013. [DOI: 10.1007/s00214-013-1430-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Gutsev GL, Weatherford CW, Belay KG, Ramachandran BR, Jena P. An all-electron density functional theory study of the structure and properties of the neutral and singly charged M12 and M13 clusters: M = Sc–Zn. J Chem Phys 2013; 138:164303. [DOI: 10.1063/1.4799917] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Xu X, Yin S, Moro R, Liang A, Bowlan J, de Heer WA. Metastability of free cobalt and iron clusters: a possible precursor to bulk ferromagnetism. PHYSICAL REVIEW LETTERS 2011; 107:057203. [PMID: 21867094 DOI: 10.1103/physrevlett.107.057203] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Indexed: 05/31/2023]
Abstract
Homonuclear cobalt and iron clusters Co(N) and Fe(N) measured in a cryogenic molecular beam exist in two states with distinct magnetic moments (μ), polarizabilities, and ionization potentials, indicating distinct valences. The μ is approximately quantized: μ(N)∼2Nμ(B) in the ground states and μ(N)(*)∼Nμ(B) in the excited states for Co; μ(N)∼3Nμ(B) and μ(N)(*)∼Nμ(B) for Fe. At a large size, the average μ of the two states converges to the bulk value with diminishing ionization potential differences. The experiments suggest localized ferromagnetism in the two states and that itinerant ferromagnetism emerges from their superposition.
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Affiliation(s)
- Xiaoshan Xu
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Margeat O, Respaud M, Amiens C, Lecante P, Chaudret B. Ultrafine metallic Fe nanoparticles: synthesis, structure and magnetism. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2010; 1:108-18. [PMID: 21977400 PMCID: PMC3045918 DOI: 10.3762/bjnano.1.13] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 10/21/2010] [Indexed: 05/31/2023]
Abstract
The results of the investigation of the structural and magnetic (static and dynamic) properties of an assembly of metallic Fe nanoparticles synthesized by an organometallic chemical method are described. These nanoparticles are embedded in a polymer, monodisperse, with a diameter below 2 nm, which corresponds to a number of around 200 atoms. The X-ray absorption near-edge structure and Mössbauer spectrum are characteristic of metallic Fe. The structural studies by wide angle X-ray scattering indicate an original polytetrahedral atomic arrangement similar to that of β-Mn, characterized by a short-range order. The average magnetic moment per Fe atom is raised to 2.59 µ(B) (for comparison, bulk value of metallic Fe: 2.2 µ(B)). Even if the spontaneous magnetization decreases rapidly as compared to bulk materials, it remains enhanced even up to room temperature. The gyromagnetic ratio measured by ferromagnetic resonance is of the same order as that of bulk Fe, which allows us to conclude that the orbital and spin contributions increase at the same rate. A large magnetic anisotropy for metallic Fe has been measured up to (3.7 ± 1.0)·10(5) J/m(3). Precise analysis of the low temperature Mössbauer spectra, show a broad distribution of large hyperfine fields. The largest hyperfine fields display the largest isomer shifts. This indicates a progressive increase of the magnetic moment inside the particle from the core to the outer shell. The components corresponding to the large hyperfine fields with large isomer shifts are indeed characteristic of surface atoms.
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Affiliation(s)
- Olivier Margeat
- Université de Toulouse, LCC - CNRS, 205, route de Narbonne, 31077 Toulouse Cedex 04 - France. Tel: +33 (0) 5 61 33 31 82; Fax: +33 (0) 5 61 55 30 03
- Université de la Méditéranée, Faculté des Sciences, GCOM2, 163 Avenue de Luminy, 13288 Marseille Cedex 09 - France. Tel: +33 (0) 6 17 24 81 15
| | - Marc Respaud
- LPCNO, INSA, 135 avenue de Rangueil, 31077 Toulouse Cedex 04 - France. Tel: +33 (0) 5 61 55 96 48; Fax: +33 (0) 5 61 55 96 97
| | - Catherine Amiens
- Université de Toulouse, LCC - CNRS, 205, route de Narbonne, 31077 Toulouse Cedex 04 - France. Tel: +33 (0) 5 61 33 31 82; Fax: +33 (0) 5 61 55 30 03
| | - Pierre Lecante
- CEMES - CNRS, 29 rue Jeanne Marvig, 31077 Toulouse Cedex 04 - France. Tel: +33 (0)5 62 25 78 51; Fax: +33 (0)5 62 25 79 99
| | - Bruno Chaudret
- Université de Toulouse, LCC - CNRS, 205, route de Narbonne, 31077 Toulouse Cedex 04 - France. Tel: +33 (0) 5 61 33 31 82; Fax: +33 (0) 5 61 55 30 03
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16
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Oviedo O, Mariscal M, Leiva E. Theoretical studies of preparation of core–shell nanoparticles by electrochemical metal deposition. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.03.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Bennemann K. Magnetic nanostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:243201. [PMID: 21393778 DOI: 10.1088/0953-8984/22/24/243201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Characteristic results of magnetism in small particles, thin films and tunnel junctions are presented. As a consequence of the reduced atomic coordination in small clusters and thin films the electronic states and density of states are modified. Thus, magnetic moments and magnetization are affected. Generally, in clusters and thin films magnetic anisotropy plays a special role. In tunnel junctions the interplay of magnetism, spin currents and superconductivity are of particular interest. In ring-like mesoscopic systems Aharonov-Bohm-induced currents are studied. Results are given for single transition metal clusters, cluster ensembles, thin films, mesoscopic structures and tunnel systems.
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Affiliation(s)
- K Bennemann
- Institute of Theoretical Physics, FU-Berlin, Arnimallee 14, D-14195 Berlin, Germany
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Auffan M, Rose J, Bottero JY, Lowry GV, Jolivet JP, Wiesner MR. Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective. NATURE NANOTECHNOLOGY 2009; 4:634-41. [PMID: 19809453 DOI: 10.1038/nnano.2009.242] [Citation(s) in RCA: 929] [Impact Index Per Article: 61.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The regulation of engineered nanoparticles requires a widely agreed definition of such particles. Nanoparticles are routinely defined as particles with sizes between about 1 and 100 nm that show properties that are not found in bulk samples of the same material. Here we argue that evidence for novel size-dependent properties alone, rather than particle size, should be the primary criterion in any definition of nanoparticles when making decisions about their regulation for environmental, health and safety reasons. We review the size-dependent properties of a variety of inorganic nanoparticles and find that particles larger than about 30 nm do not in general show properties that would require regulatory scrutiny beyond that required for their bulk counterparts.
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Affiliation(s)
- Mélanie Auffan
- Center for the Environmental Implications of NanoTechnology CEINT, Duke University, 121 Hudson Hall, Durham, North Carolina 27707, USA
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Gruner ME, Entel P. Simulating functional magnetic materials on supercomputers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:293201. [PMID: 21828528 DOI: 10.1088/0953-8984/21/29/293201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The recent passing of the petaflop per second landmark by the Roadrunner project at the Los Alamos National Laboratory marks a preliminary peak of an impressive world-wide development in the high-performance scientific computing sector. Also, purely academic state-of-the-art supercomputers such as the IBM Blue Gene/P at Forschungszentrum Jülich allow us nowadays to investigate large systems of the order of 10(3) spin polarized transition metal atoms by means of density functional theory. Three applications will be presented where large-scale ab initio calculations contribute to the understanding of key properties emerging from a close interrelation between structure and magnetism. The first two examples discuss the size dependent evolution of equilibrium structural motifs in elementary iron and binary Fe-Pt and Co-Pt transition metal nanoparticles, which are currently discussed as promising candidates for ultra-high-density magnetic data storage media. However, the preference for multiply twinned morphologies at smaller cluster sizes counteracts the formation of a single-crystalline L1(0) phase, which alone provides the required hard magnetic properties. The third application is concerned with the magnetic shape memory effect in the Ni-Mn-Ga Heusler alloy, which is a technologically relevant candidate for magnetomechanical actuators and sensors. In this material strains of up to 10% can be induced by external magnetic fields due to the field induced shifting of martensitic twin boundaries, requiring an extremely high mobility of the martensitic twin boundaries, but also the selection of the appropriate martensitic structure from the rich phase diagram.
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Affiliation(s)
- Markus Ernst Gruner
- Physics Department and Centre for Nanointegration CENIDE, University of Duisburg-Essen, Duisburg Campus, 47048 Duisburg, Germany
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Muñoz-Navia M, Dorantes-Dávila J, Zitoun D, Amiens C, Chaudret B, Casanove MJ, Lecante P, Jaouen N, Rogalev A, Respaud M, Pastor GM. Magnetic properties of CoNRhMnanoparticles: experiment and theory. Faraday Discuss 2008; 138:181-92; discussion 211-23, 433-4. [DOI: 10.1039/b705122k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Ayuela A, March NH, Klein DJ. Optimized Geometry of the Cluster Gd2O3 and Proposed Antiferromagnetic Alignment of f-Electron Magnetic Moment. J Phys Chem A 2007; 111:10162-5. [PMID: 17880190 DOI: 10.1021/jp0745790] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is currently experimental interest in assemblies of Gd2O3 clusters. This has motivated the present study in which a single such cluster in free space is examined quantitatively by spin-density functional theory, with appropriate relativistic corrections incorporated for Gd. First, the nuclear geometry of the cluster is optimized, and it is found to be such that the two Gd atoms lie in a symmetry axis perpendicular to the isosceles triangle formed by the O atoms. Then, a careful study is made of the magnetic arrangement of the localized f-electron moments on the two Gd atoms. The prediction of the present treatment is that the localized spins are aligned antiferromagnetically. An alternative picture using superexchange ideas leads to the same conclusion.
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Affiliation(s)
- A Ayuela
- Centro Mixto CSIC/UPV, Unidad de Física de Materiales, 20018 San Sebastian, Spain.
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Payne FW, Jiang W, Bloomfield LA. Magnetism and magnetic isomers in free chromium clusters. PHYSICAL REVIEW LETTERS 2006; 97:193401. [PMID: 17155626 DOI: 10.1103/physrevlett.97.193401] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Indexed: 05/12/2023]
Abstract
We have used the Stern-Gerlach deflection technique to study magnetism in chromium clusters of 20-133 atoms at temperatures between 60 and 100 K. We observe that these clusters have large magnetic moments and respond superparamagnetically to applied magnetic fields. Using superparamagnetic theory, we have determined the moment per atom for each cluster size and find that it often far exceeds the moment per atom present anywhere in the bulk antiferromagnetic lattice. Remarkably, our cluster beam contains two magnetically distinguishable forms of each cluster size with > or =34 atoms. We attribute this observation to structural isomers.
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Affiliation(s)
- F W Payne
- Department of Physics, University of Virginia, Charlottesville, VA 22904, USA
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Tada T, Kondo M, Yoshizawa K. Green's function formalism coupled with Gaussian broadening of discrete states for quantum transport: application to atomic and molecular wires. J Chem Phys 2006; 121:8050-7. [PMID: 15485269 DOI: 10.1063/1.1799991] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A Green's function formalism incorporating broadened density of states (DOS) is proposed for the calculation of electrical conductance. In cluster-molecule-cluster systems, broadened DOS of the clusters are defined as continuous DOS of electrodes and used to calculate Green's function of electrodes. This approach combined with density functional theory is applied to the electrical transmission of gold atomic wires and molecular wires consisting of benzene-1,4-dithiolate, benzene-1,4-dimethanethiolate, 4,4(')-bipyridine, hexane dithiolate, and octane dithiolate. The B3LYP, B3PW91, MPW1PW91, SVWN, and BPW91 functionals with the LANL2DZ, CEP, and SDD basis sets are employed in the calculation of conductance. The width parameter was successfully determined to reproduce the quantum unit of conductance 2e(2)/h in gold atomic wires. The combination of the B3LYP hybrid functional and the CEP-31G basis set is excellent in reproducing measured conductances of molecular wires by Tao et al. [Science 301, 1221 (2003); J. Am. Chem. Soc. 125, 16164 (2003); Nano Lett. 4, 267 (2004)].
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Affiliation(s)
- Tomofumi Tada
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 812-8581, Japan
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Tiago ML, Zhou Y, Alemany MMG, Saad Y, Chelikowsky JR. Evolution of magnetism in iron from the atom to the bulk. PHYSICAL REVIEW LETTERS 2006; 97:147201. [PMID: 17155287 DOI: 10.1103/physrevlett.97.147201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Indexed: 05/12/2023]
Abstract
The evolution of the magnetic moment in iron clusters containing 20-400 atoms is investigated using first-principles numerical calculations based on density-functional theory and real-space pseudopotentials. Three families of clusters are studied, characterized by the arrangement of atoms: icosahedral, body-centered cubic centered on an atom site, and body-centered cubic centered on the bridge between two neighboring atoms. We find an overall decrease of magnetic moment as the clusters grow in size towards the bulk limit. Clusters with faceted surfaces are predicted to have magnetic moment lower than other clusters with similar size. As a result, the magnetic moment is observed to decrease as function of size in a nonmonotonic manner, which explains measurements performed at low temperatures.
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Affiliation(s)
- Murilo L Tiago
- Center for Computational Materials, Institute for Computational Engineering and Sciences, University of Texas, Austin, Texas 78712, USA
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26
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Muñoz-Navia M, Dorantes-Dávila J, Terrones M, Hayashi T, Kim Y, Endo M, Dresselhaus M, Terrones H. Synthesis and electronic properties of coalesced graphitic nanocones. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.03.095] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lee G, Huh S, Jung H. Experimental evidence of structural transition from fcc to bulk bcc in nanophase metal clusters of (Fe)n, (Cr)n, (Mo)n and (W)n produced by CO2 laser multiphoton decomposition of metal carbonyls. J Mol Struct 1998. [DOI: 10.1016/s0022-2860(97)00228-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wu H, Desai SR, Wang LS. Evolution of the Electronic Structure of Small Vanadium Clusters from Molecular to Bulklike. PHYSICAL REVIEW LETTERS 1996; 77:2436-2439. [PMID: 10061953 DOI: 10.1103/physrevlett.77.2436] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Bouarab S, Vega A, Alonso JA, Iñiguez MP. Tight-binding study of the ionization of iron clusters. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:3003-3006. [PMID: 9986185 DOI: 10.1103/physrevb.54.3003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Minemoto S, Terasaki A, Kondow T. Electronic structures of cobalt cluster cations: Photodissociation spectroscopy of Co+nAr (n=3–5) in the visible to near‐infrared range. J Chem Phys 1996. [DOI: 10.1063/1.471338] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pastor GM, Hirsch R, Mühlschlegel B. Magnetism and structure of small clusters: An exact treatment of electron correlations. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:10382-10396. [PMID: 9982609 DOI: 10.1103/physrevb.53.10382] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Piveteau B, Desjonquères MC, Oles AM, Spanjaard D. Magnetic properties of 4d transition-metal clusters. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:9251-9266. [PMID: 9982427 DOI: 10.1103/physrevb.53.9251] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Bouarab S, Nait-Laziz H, Khan MA, Demangeat C, Dreyssé H, Benakki M. Spin polarization of Mn layers on Fe(001). PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:10127-10135. [PMID: 9980061 DOI: 10.1103/physrevb.52.10127] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Pastor GM, Dorantes-Dávila J, Pick S, Dreyssé H. Magnetic anisotropy of 3d transition-metal clusters. PHYSICAL REVIEW LETTERS 1995; 75:326-329. [PMID: 10059666 DOI: 10.1103/physrevlett.75.326] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Wang L, Cheng H, Fan J. Photoelectron spectroscopy of size‐selected transition metal clusters: Fe−n, n=3–24. J Chem Phys 1995. [DOI: 10.1063/1.468817] [Citation(s) in RCA: 378] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Dorantes-Dávila J, Pastor GM. Alternative local approach to nonorthogonal tight-binding theory: Environment dependence of the interaction parameters in an orthogonal basis. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:16627-16634. [PMID: 9978666 DOI: 10.1103/physrevb.51.16627] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ruckman MW, Xia B, Shih D. Photoemission study of iron deposited on fullerenes. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:17682-17685. [PMID: 9976190 DOI: 10.1103/physrevb.50.17682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Miura K, Kimura H, Imanaga S. Calculation of the low-spin and high-spin states of Ih Co13. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:10335-10338. [PMID: 9975121 DOI: 10.1103/physrevb.50.10335] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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