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Luis F Cuñado J, Pedrosa J, Ajejas F, Perna P, Miranda R, Camarero J. Direct observation of temperature-driven magnetic symmetry transitions by vectorial resolved MOKE magnetometry. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:405805. [PMID: 28699618 DOI: 10.1088/1361-648x/aa7f45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Angle- and temperature-dependent vectorial magnetometry measurements are necessary to disentangle the effective magnetic symmetry in magnetic nanostructures. Here we present a detailed study on an Fe(1 0 0) thin film system with competing collinear biaxial (four-fold symmetry) and uniaxial (two-fold) magnetic anisotropies, carried out with our recently developed full angular/broad temperature range/vectorial-resolved magneto-optical Kerr effect magnetometer, named TRISTAN. The data give direct views on the angular and temperature dependence of the magnetization reversal pathways, from which characteristic axes, remanences, critical fields, domain wall types, and effective magnetic symmetry are obtained. In particular, although the remanence shows four-fold angular symmetry for all investigated temperatures (15 K-400 K), the critical fields show strong temperature and angular dependencies and the reversal mechanism changes for specific angles at a given (angle-dependent) critical temperature, showing signatures of an additional collinear two-fold symmetry. This symmetry-breaking is more relevant as temperature increases to room temperature. It originates from the competition between two anisotropy contributions with different symmetry and temperature evolution. The results highlight the importance of combining temperature and angular studies, and the need to look at different magnetic parameters to unravel the underlying magnetic symmetries and temperature evolutions of the symmetry-breaking effects in magnetic nanostructures.
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Affiliation(s)
- Jose Luis F Cuñado
- IMDEA-Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain. Departamento de Física de la Materia Condensada and Instituto 'Nicolás Cabrera', Universidad Autónoma de Madrid, 28049 Madrid, Spain
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2
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Manna S, Przybylski M, Sander D, Kirschner J. The role of electron confinement in Pd films for the oscillatory magnetic anisotropy in an adjacent Co layer. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:456001. [PMID: 27609044 DOI: 10.1088/0953-8984/28/45/456001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate the interplay between quantum well states in Pd and the magnetic anisotropy in Pd/Co/Cu (0 0 1) by combined scanning tunneling spectroscopy (STS) and magneto optical Kerr effect (MOKE) measurements. Low temperature scanning tunneling spectroscopy reveals occupied and unoccupied quantum well states (QWS) in atomically flat Pd films on Co/Cu (0 0 1). These states give rise to sharp peaks in the differential conductance spectra. A quantitative analysis of the spectra reveals the electronic dispersion of the Pd (0 0 1) d-band ([Formula: see text]-type) along the [Formula: see text]-X direction. In situ MOKE experiments on Pd/Co/Cu (1, 1, 13) uncover a periodic variation of the in-plane uniaxial magnetic anisotropy as a function of Pd thickness with a period of 6 atomic layers Pd. STS shows that QWS in Pd cross the Fermi level with the same periodicity of 6 atomic layers. Backed by previous theoretical work we ascribe the variation of the magnetic anisotropy in Co to QWS in the Pd overlayer. Our results suggest a novel venue towards tailoring uniaxial magnetic anisotropy of ferromagnetic films by exploiting QWS in an adjacent material with large spin-orbit coupling.
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Affiliation(s)
- Sujit Manna
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
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3
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Unveiling the Mechanism for the Split Hysteresis Loop in Epitaxial Co2Fe1-xMnxAl Full-Heusler Alloy Films. Sci Rep 2016; 6:18615. [PMID: 26733075 PMCID: PMC4702088 DOI: 10.1038/srep18615] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 11/25/2015] [Indexed: 12/04/2022] Open
Abstract
Utilizing epitaxial Co2Fe1-xMnxAl full-Heusler alloy
films on GaAs (001), we address the controversy over the analysis for the split
hysteresis loop which is commonly found in systems consisting of both uniaxial and
fourfold anisotropies. Quantitative comparisons are carried out on the values of the
twofold and fourfold anisotropy fields obtained with ferromagnetic resonance and
vibrating sample magnetometer measurements. The most suitable model for describing
the split hysteresis loop is identified. In combination with the component resolved
magnetization measurements, these results provide compelling evidences that the
switching is caused by the domain wall nucleation and movements with the switching
fields centered at the point where the energy landscape shows equal minima for
magnetization orienting near the easy axis and the field supported hard axis.
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4
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Syrlybekov A, Wu HC, Mauit O, Wu YC, Maguire P, Khalid A, Coileáin CÓ, Farrell L, Heng CL, Abid M, Liu H, Yang L, Zhang HZ, Shvets IV. Electrical-field-driven metal-insulator transition tuned with self-aligned atomic defects. NANOSCALE 2015; 7:14055-14061. [PMID: 26239065 DOI: 10.1039/c5nr03251b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recently, significant attention has been paid to the resistance switching (RS) behaviour in Fe3O4 and it was explained through the analogy of the electrically driven metal-insulator transition based on the quantum tunneling theory. Here, we propose a method to experimentally support this explanation and provide a way to tune the critical switching parameter by introducing self-aligned localized impurities through the growth of Fe3O4 thin films on stepped SrTiO3 substrates. Anisotropic behavior in the RS was observed, where a lower switching voltage in the range of 10(4) V cm(-1) is required to switch Fe3O4 from a high conducting state to a low conducting state when the electrical field is applied along the steps. The anisotropic RS behavior is attributed to a high density array of anti-phase boundaries (APBs) formed at the step edges and thus are aligned along the same direction in the film which act as a train of hotspot forming conduits for resonant tunneling. Our experimental studies open an interesting window to tune the electrical-field-driven metal-insulator transition in strongly correlated systems.
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Affiliation(s)
- Askar Syrlybekov
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
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5
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Xu Y, Chen L, Wang X, Yao W, Zhang Q. Recent advances in noble metal based composite nanocatalysts: colloidal synthesis, properties, and catalytic applications. NANOSCALE 2015; 7:10559-10583. [PMID: 26036784 DOI: 10.1039/c5nr02216a] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This Review article provides a report on progress in the synthesis, properties and catalytic applications of noble metal based composite nanomaterials. We begin with a brief discussion on the categories of various composite materials. We then present some important colloidal synthetic approaches to the composite nanostructures; here, major attention has been paid to bimetallic nanoparticles. We also introduce some important physiochemical properties that are beneficial from composite nanomaterials. Finally, we highlight the catalytic applications of such composite nanoparticles and conclude with remarks on prospective future directions.
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Affiliation(s)
- Yong Xu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, P. R. China.
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6
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Ma S, Tan A, Deng JX, Li J, Zhang ZD, Hwang C, Qiu ZQ. Tailoring the magnetic anisotropy of Py/Ni bilayer films using well aligned atomic steps on Cu(001). Sci Rep 2015; 5:11055. [PMID: 26067408 PMCID: PMC4464147 DOI: 10.1038/srep11055] [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: 01/30/2015] [Accepted: 05/11/2015] [Indexed: 11/09/2022] Open
Abstract
Tailoring the spin orientation at the atomic scale has been a key task in spintronics technology. While controlling the out-of-plane to in-plane spin orientation has been achieved by a precise control of the perpendicular magnetic anisotropy at atomic layer thickness level, a design and control of the in-plane magnetic anisotropy has not yet been well developed. On well aligned atomic steps of a 6° vicinal Cu(001) surface with steps parallel to the [110] axis, we grow Py/Ni overlayer films epitaxially to permit a systematic exploration of the step-induced in-plane magnetic anisotropy as a function of both the Py and the Ni film thicknesses. We found that the atomic steps from the vicinal Cu(001) induce an in-plane uniaxial magnetic anisotropy that favors both Py and Ni magnetizations perpendicular to the steps, opposite to the behavior of Co on vicinal Cu(001). In addition, thickness-dependent study shows that the Ni films exhibit different magnetic anisotropy below and above ~6 ML Ni thickness.
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Affiliation(s)
- S Ma
- 1] Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China [2] Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - A Tan
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - J X Deng
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - J Li
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - Z D Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Korea
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
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7
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Cuñado JLF, Pedrosa J, Ajejas F, Bollero A, Perna P, Teran FJ, Miranda R, Camarero J. Note: Vectorial-magneto optical Kerr effect technique combined with variable temperature and full angular range all in a single setup. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:046109. [PMID: 25933907 DOI: 10.1063/1.4919411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here, we report on a versatile full angular resolved/broad temperature range/vectorial magneto optical Kerr effect (MOKE) magnetometer, named TRISTAN. Its versatility relies on its capacity to probe temperature and angular dependencies of magnetization reversal processes without the need to do any intervention on the apparatus during measurements. The setup is a combination of a vectorial MOKE bench and a cryostat with optical access. The cryostat has a motorized rotatable sample holder with azimuthal correction. It allows for simultaneous and quantitative acquisition of the two in-plane magnetization components during the hysteresis loop at different temperatures from 4 K up to 500 K and in the whole angular range, without neither changing magnet orientation nor opening the cryostat. Measurements performed in a model system with competing collinear biaxial and uniaxial contributions are presented to illustrate its capabilities.
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Affiliation(s)
- Jose Luis F Cuñado
- Departamento de Física de la Materia Condensada and Instituto "Nicolás Cabrera," Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Javier Pedrosa
- Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Fernando Ajejas
- Departamento de Física de la Materia Condensada and Instituto "Nicolás Cabrera," Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Alberto Bollero
- Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Paolo Perna
- Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Francisco J Teran
- Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rodolfo Miranda
- Departamento de Física de la Materia Condensada and Instituto "Nicolás Cabrera," Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Julio Camarero
- Departamento de Física de la Materia Condensada and Instituto "Nicolás Cabrera," Universidad Autónoma de Madrid, 28049 Madrid, Spain
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8
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Dąbrowski M, Peixoto TRF, Pazgan M, Winkelmann A, Cinal M, Nakagawa T, Takagi Y, Yokoyama T, Bisio F, Bauer U, Yildiz F, Przybylski M, Kirschner J. Oscillations of the orbital magnetic moment due to d-band quantum well states. PHYSICAL REVIEW LETTERS 2014; 113:067203. [PMID: 25148348 DOI: 10.1103/physrevlett.113.067203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Indexed: 06/03/2023]
Abstract
The effect of electron confinement on the magnetocrystalline anisotropy of ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr effect measurements. Pronounced thickness-dependent variations in the magnetocrystalline anisotropy are ascribed to periodic changes in the density of states at the Fermi level, induced by quantization of d(xz), d(yz) out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, the orbital magnetic moment, and the magnetocrystalline anisotropy.
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Affiliation(s)
- M Dąbrowski
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - T R F Peixoto
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - M Pazgan
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - A Winkelmann
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - M Cinal
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - T Nakagawa
- Institute for Molecular Science, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
| | - Y Takagi
- Institute for Molecular Science, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
| | - T Yokoyama
- Institute for Molecular Science, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
| | - F Bisio
- CNR-SPIN Corso Perrone 24, I-16152 Genova, Italy
| | - U Bauer
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - F Yildiz
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany
| | - M Przybylski
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany and Faculty of Physics and Applied Computer Science, and Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Kraków, Poland
| | - J Kirschner
- Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany and Naturwissenschaftliche Fakultät II, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle, Germany
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9
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Bounour-Bouzamouche W, Chérif SM, Farhat S, Roussigné Y, Lungu C, Mazaleyrat F, Guerioune M. Lithography-free synthesis of nanostructured cobalt on Si (111) surfaces: structural and magnetic properties. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20147505012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Ryabchenko SM, Kalita VM, Kulik MM, Lozenko AF, Nevdacha VV, Pogorily AN, Kravets AF, Podyalovskiy DY, Vovk AY, Borges RP, Godinho M, Korenivski V. Rotatable magnetic anisotropy in Si/SiO2/(Co2Fe)(x)Ge(1-x) Heusler alloy films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:416003. [PMID: 24025408 DOI: 10.1088/0953-8984/25/41/416003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Polycrystalline (Co2Fe)(x)Ge(1-x) Heusler alloy films are fabricated by sputtering on amorphous substrates and shown to possess three types of magnetic anisotropy. The nearly stoichiometric composition of x = 50 m.f.% shows a rectangular hysteresis loop and isotropic coercive and ferromagnetic resonance fields when the film is field-magnetized along any in-plane direction, thus predominantly possessing rotatable in-plane magnetic anisotropy. Higher-x compositions show evidence of two- and fourfold in-plane anisotropy superposed on the rotatable one. A qualitative model of the observed anisotropic magnetic properties is proposed. The model explains the rotatable anisotropy by taking into account dry friction for the in-plane rotation of the magnetization direction in a fine-grained polycrystalline film with the magnetic grain size smaller than the correlation length of the inter-grain exchange interaction. The observed two- and fourfold magnetic anisotropy contributions are attributed to partial texturing of the fine-grained films, even though the films are grown on amorphous SiO2 substrates. These results should be valuable for understanding and controlling the magnetic behaviour of highly spin-polarized Heusler alloy films used in various magnetic nanodevices.
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Affiliation(s)
- S M Ryabchenko
- Institute of Physics, National Academy of Sciences of Ukraine, Nauki 46, 03680 Kyiv, Ukraine
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11
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Li J, Jin E, Son H, Tan A, Cao WN, Hwang C, Qiu ZQ. Design of a vector magnet for the measurements of anisotropic magnetoresistance and rotational magneto-optic Kerr effect. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:033906. [PMID: 22462937 DOI: 10.1063/1.3698297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A vector magnet is designed and assembled with two electromagnets to produce a rotational magnetic field in any direction within a plane. This design allows a rotation of the magnetic field without a mechanical rotation of the magnets. The fast speed of the field rotation (~10 s for a complete 360° rotation) and the stability against mechanical vibration easily overcome the slow drifting effect in anisotropic magnetoresistance (AMR) and rotational magneto-optic Kerr effect (ROTMOKE) measurements. As an example we applied this vector magnet to carry out AMR and ROTMOKE measurements on epitaxial growth of Fe(10 nm)∕MgO(001) films. The result demonstrates the stability and high quality of the vector magnet in determining the magnetic anisotropy of magnetic thin films using AMR and ROTMOKE techniques.
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Affiliation(s)
- J Li
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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12
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Wei YM, Fu YC, Yan JW, Sun CF, Shi Z, Xie ZX, Wu DY, Mao BW. Growth and Shape-Ordering of Iron Nanostructures on Au Single Crystalline Electrodes in an Ionic Liquid: A Paradigm of Magnetostatic Coupling. J Am Chem Soc 2010; 132:8152-7. [DOI: 10.1021/ja1021816] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yi-Min Wei
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Yong-Chun Fu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Jia-Wei Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Chun-Feng Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Zhan Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Zhao-Xiong Xie
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - De-Yin Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
| | - Bing-Wei Mao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, and Department of Materials Science and Engineering, College of Materials, Xiamen University, 361005 Xiamen, China
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13
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Corso M, Schiller F, Fernández L, Cordón J, Ortega JE. Electronic states in faceted Au(111) studied with curved crystal surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:353001. [PMID: 21828621 DOI: 10.1088/0953-8984/21/35/353001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Vicinal Au(111) surfaces exhibit periodic faceting within a wide range of miscut angles. There, the system segregates two alternating phases with different step lattice constants d(w) and d(n). Using a curved crystal surface that allows a smooth variation of the surface orientation, we have studied, as a function of the miscut angle, the evolution of Au(111) faceted structures by scanning tunneling microscopy, and their electronic surface states by angle-resolved photoemission. We observe that surface bands reflect the two-phase character of the faceted system, i.e. we find d(w)- and d(n)-like states that evolve accordingly to the faceted structure. Using a photoemission calculation we prove that the apparently complex topology hides relatively simple physics, i.e. the same free-electron-like dispersion and repulsive step scattering that feature surface bands in stepped noble metal surfaces. On the grounds of such simulations, we discuss the possible interference of the electronic energy in the delicate free energy balance that determines the critical size of reconstructed (d(w)) and unreconstructed (d(n)) terraces during Au faceting.
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Affiliation(s)
- M Corso
- DIPC, Manuel Lardizábal 4, E-20018 San Sebastián, Spain
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14
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Li J, Przybylski M, Yildiz F, Ma XD, Wu YZ. Oscillatory magnetic anisotropy originating from quantum well states in Fe films. PHYSICAL REVIEW LETTERS 2009; 102:207206. [PMID: 19519071 DOI: 10.1103/physrevlett.102.207206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Indexed: 05/27/2023]
Abstract
The magnetic anisotropy of Fe film grown on vicinal Ag(1,1,10) surfaces was studied with the in situ magneto-optic Kerr effect. Below 200 K, strong oscillations of the uniaxial magnetic anisotropy as a function of Fe thickness with a period of 5.7 monolayers are found, which can even cause the easy magnetization axis to oscillate between perpendicular and parallel to the steps. Such novel oscillation of the anisotropy is attributed to the quantum well states of d-band electrons at the Fermi level in the Fe film. This is unlike the previously observed oscillatory behaviors of ferromagnetic films caused by the quantum well states in nonmagnetic interfacing layers.
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Affiliation(s)
- J Li
- Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle, Germany
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15
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Stupakiewicz A, Maziewski A, Matlak K, Spiridis N, Slezak M, Slezak T, Zajac M, Korecki J. Tailoring of the perpendicular magnetization component in ferromagnetic films on a vicinal substrate. PHYSICAL REVIEW LETTERS 2008; 101:217202. [PMID: 19113447 DOI: 10.1103/physrevlett.101.217202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Indexed: 05/27/2023]
Abstract
We have engineered the magnetic properties of 1-8 nm Co films epitaxially grown on an Au-buffered bifacial W(110)/W(540) single crystal. The surface of Au/W(110) was atomically flat, whereas the Au/W(540) followed the morphology of the vicinal W surface, showing a regular array of monoatomic steps. For Co grown on Au/W(540), the existence of the out-of-plane magnetization component extended strongly to a thickness d of about 8 nm, which was accompanied by an anomalous increase of the out-of-plane switching field with increasing d. In addition, the process of up-down magnetization switching could be realized with both a perpendicular and in-plane external magnetic field.
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Affiliation(s)
- A Stupakiewicz
- Laboratory of Magnetism, University of Bialystok, Lipowa 41, 15-424 Bialystok, Poland
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16
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Pärnaste M, Marcellini M, Holmström E, Bock N, Fransson J, Eriksson O, Hjörvarsson B. Dimensionality crossover in the induced magnetization of Pd layers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:246213. [PMID: 21694056 DOI: 10.1088/0953-8984/19/24/246213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The magnetic ordering of a series of samples consisting of ultrathin Fe layers embedded in Pd was investigated using the magneto-optical Kerr effect. The samples consisted of a single Fe layer with nominal thickness 0.2≤d(Fe)≤1.6 monolayers sandwiched between two 20 monolayer Pd layers. A dimensionality crossover from two dimensions to three dimensions occurs as d(Fe) is increased from 0.4 to 1.0 monolayers. First-principles calculations were performed in order to determine the magnetic profile, and we used a spin-wave quantum well model for obtaining a qualitative description of the dimensionality crossover. The results clearly prove the existence of a dimensionality crossover in the induced magnetization, opening new routes for addressing the influence of extension on order.
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Affiliation(s)
- Martin Pärnaste
- Department of Physics, Uppsala University, Box 530, 751 21 Uppsala, Sweden
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17
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Bisio F, Moroni R, Buatier de Mongeot F, Canepa M, Mattera L. Isolating the step contribution to the uniaxial magnetic anisotropy in nanostructured Fe/Ag(001) films. PHYSICAL REVIEW LETTERS 2006; 96:057204. [PMID: 16486975 DOI: 10.1103/physrevlett.96.057204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Indexed: 05/06/2023]
Abstract
We have investigated the possibility of isolating the step-induced in-plane uniaxial magnetic anisotropy in Fe/Ag(001) films on which nanoscale surface ripples were fabricated by the ion sculpting technique. For rippled Fe films deposited on flat Ag(001), the steps created along the ripple sidewalls are shown to be the only source of uniaxial anisotropy. Ion sculpting of ultrathin magnetic films allows one to selectively study the step-induced anisotropy and to investigate the correlation between local atomic environment and magnetic properties.
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Affiliation(s)
- F Bisio
- CNR-INFM Unità di Genova and Dipartimento di Fisica, Università di Genova, via Dodecaneso 33, I-16146 Genova, Italy
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Gambardella P, Dallmeyer A, Maiti K, Malagoli MC, Rusponi S, Ohresser P, Eberhardt W, Carbone C, Kern K. Oscillatory magnetic anisotropy in one-dimensional atomic wires. PHYSICAL REVIEW LETTERS 2004; 93:077203. [PMID: 15324270 DOI: 10.1103/physrevlett.93.077203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2004] [Indexed: 05/24/2023]
Abstract
One-dimensional Co atomic wires grown on Pt(997) have been investigated by x-ray magnetic circular dichroism. Strong changes of the magnetic properties are observed as the system evolves from 1D- to 2D-like. The easy axis of magnetization, the magnetic anisotropy energy, and the coercive field oscillate as a function of the transverse width of the wires, in agreement with theoretical predictions for 1D metal systems.
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Affiliation(s)
- P Gambardella
- Institut de Physique des Nanostructures, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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Moroni R, Sekiba D, Buatier de Mongeot F, Gonella G, Boragno C, Mattera L, Valbusa U. Uniaxial magnetic anisotropy in nanostructured Co/Cu(001): from surface ripples to nanowires. PHYSICAL REVIEW LETTERS 2003; 91:167207. [PMID: 14611439 DOI: 10.1103/physrevlett.91.167207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2003] [Indexed: 05/24/2023]
Abstract
We have investigated the correlation between morphology and magnetic anisotropy in nanostructured Co films on Cu(001). The formation of nanoscale ripples by ion erosion is found to deeply affect the magnetic properties of the Co film. A surface-type uniaxial magnetic anisotropy with easy axis parallel to the ripples is observed. The origin of the magnetic anisotropy has been identified with the modification of thermodynamic-step distribution induced by ripple formation. At higher ion doses, when Co ripples detach and crystalline nanowires form, a strong enhancement of the magnetic anisotropy due to magnetostatic contributions is observed.
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Affiliation(s)
- R Moroni
- Unità INFM di Genova, Dipartimento di Fisica dell'Università di Genova, and IMEM-CNR Sezione di Genova, via Dodecaneso 33, I-16146 Genova, Italy
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Mireles HC, Erskine JL. Surface-step-induced double magnetic switching of Fe on vicinal W(100). PHYSICAL REVIEW LETTERS 2001; 87:037201. [PMID: 11461585 DOI: 10.1103/physrevlett.87.037201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Indexed: 05/23/2023]
Abstract
Two-level magnetic switching of a bilayer epitaxial Fe film grown on a graded stepped W(100) surface is observed using the magneto-optic Kerr effect. Hysteresis loops produced by the film at a location on the curved W(100) surface corresponding to a vicinal angle of 6.4 degrees exhibit two abrupt jumps in magnetization following spin orientation perpendicular to the steps resulting from surface-step-induced anisotropy. The two-step process can be understood in terms of abrupt depinning of spins in two inequivalent microdomains associated with the stepped surface. The results suggest a new realm of ultrathin film micromagnetics in which characteristic dimensions of 20-30 A can play a dominant role.
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Affiliation(s)
- H C Mireles
- Department of Physics, The University of Texas at Austin, Austin, Texas 78712-1081, USA
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