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Ukleev V, Luo C, Abrudan R, Aqeel A, Back CH, Radu F. Chiral surface spin textures in Cu 2OSeO 3 unveiled by soft X-ray scattering in specular reflection geometry. Sci Technol Adv Mater 2022; 23:682-690. [PMID: 36277505 PMCID: PMC9586675 DOI: 10.1080/14686996.2022.2131466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/23/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Resonant elastic soft X-ray magnetic scattering (XRMS) is a powerful tool to explore long-periodic spin textures in single crystals. However, due to the limited momentum transfer range imposed by long wavelengths of photons in the soft x-ray region, Bragg diffraction is restricted to crystals with the large lattice parameters. Alternatively, small-angle X-ray scattering has been involved in the soft energy X-ray range which, however, brings in difficulties with the sample preparation that involves focused ion beam milling to thin down the crystal to below a few hundred nm thickness. We show how to circumvent these restrictions using XRMS in specular reflection from a sub-nanometer smooth crystal surface. The method allows observing diffraction peaks from the helical and conical spin modulations at the surface of a Cu 2 OSeO 3 single crystal and probing their corresponding chirality as contributions to the dichroic scattered intensity. The results suggest a promising way to carry out XRMS studies on a plethora of noncentrosymmetric systems hitherto unexplored with soft X-rays due to the absence of the commensurate Bragg peaks in the available momentum transfer range.
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Affiliation(s)
- V. Ukleev
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - C. Luo
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
- Physik-Department, Technische Universität München, Garching, Germany
| | - R. Abrudan
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - A. Aqeel
- Physik-Department, Technische Universität München, Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), München, Germany
| | - C. H. Back
- Physik-Department, Technische Universität München, Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), München, Germany
| | - F. Radu
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
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2
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Tornos J, Gallego F, Valencia S, Liu YH, Rouco V, Lauter V, Abrudan R, Luo C, Ryll H, Wang Q, Hernandez-Martin D, Orfila G, Cabero M, Cuellar F, Arias D, Mompean FJ, Garcia-Hernandez M, Radu F, Charlton TR, Rivera-Calzada A, Sefrioui Z, Te Velthuis SGE, Leon C, Santamaria J. Ferroelectric Control of Interface Spin Filtering in Multiferroic Tunnel Junctions. Phys Rev Lett 2019; 122:037601. [PMID: 30735408 DOI: 10.1103/physrevlett.122.037601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/27/2018] [Indexed: 06/09/2023]
Abstract
The electronic reconstruction occurring at oxide interfaces may be the source of interesting device concepts for future oxide electronics. Among oxide devices, multiferroic tunnel junctions are being actively investigated as they offer the possibility to modulate the junction current by independently controlling the switching of the magnetization of the electrodes and of the ferroelectric polarization of the barrier. In this Letter, we show that the spin reconstruction at the interfaces of a La_{0.7}Sr_{0.3}MnO_{3}/BaTiO_{3}/La_{0.7}Sr_{0.3}MnO_{3} multiferroic tunnel junction is the origin of a spin filtering functionality that can be turned on and off by reversing the ferroelectric polarization. The ferroelectrically controlled interface spin filter enables a giant electrical modulation of the tunneling magnetoresistance between values of 10% and 1000%, which could inspire device concepts in oxides-based low dissipation spintronics.
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Affiliation(s)
- J Tornos
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - F Gallego
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - S Valencia
- Hemholtz-Zentrum Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Y H Liu
- Oak Ridge National Laboratory, Neutron Scattering Division, Oak Ridge, Tennessee 37831, USA
- Argonne National Laboratory, Materials Science Division, Argonne, Illinois 60439, USA
| | - V Rouco
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - V Lauter
- Oak Ridge National Laboratory, Neutron Scattering Division, Oak Ridge, Tennessee 37831, USA
| | - R Abrudan
- Hemholtz-Zentrum Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Institut für Experimentalphysik (Festkörperphysik), Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - C Luo
- Hemholtz-Zentrum Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - H Ryll
- Hemholtz-Zentrum Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Q Wang
- Argonne National Laboratory, Materials Science Division, Argonne, Illinois 60439, USA
| | | | - G Orfila
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - M Cabero
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - F Cuellar
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - D Arias
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - F J Mompean
- 2D-Foundry Group, Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, 28049 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
| | - M Garcia-Hernandez
- 2D-Foundry Group, Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, 28049 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
| | - F Radu
- Hemholtz-Zentrum Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - T R Charlton
- ISIS, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, United Kingdom
| | - A Rivera-Calzada
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
| | - Z Sefrioui
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
- GFMC, Instituto de Magnetismo Aplicado, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - S G E Te Velthuis
- Argonne National Laboratory, Materials Science Division, Argonne, Illinois 60439, USA
| | - C Leon
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
- GFMC, Instituto de Magnetismo Aplicado, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - J Santamaria
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
- GFMC, Instituto de Magnetismo Aplicado, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Salikhov R, Reichel L, Zingsem B, Abrudan R, Edström A, Thonig D, Rusz J, Eriksson O, Schultz L, Fähler S, Farle M, Wiedwald U. Enhanced spin-orbit coupling in tetragonally strained Fe-Co-B films. J Phys Condens Matter 2017; 29:275802. [PMID: 28530633 DOI: 10.1088/1361-648x/aa7498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Tetragonally strained interstitial Fe-Co-B alloys were synthesized as epitaxial films grown on a 20 nm thick Au0.55Cu0.45 buffer layer. Different ratios of the perpendicular to in-plane lattice constant c/a = 1.013, 1.034 and 1.02 were stabilized by adding interstitial boron with different concentrations 0, 4, and 10 at.%, respectively. Using ferromagnetic resonance (FMR) and x-ray magnetic circular dichroism (XMCD) we found that the total orbital magnetic moment significantly increases with increasing c/a ratio, indicating that reduced crystal symmetry and interstitial B leads to a noticeable enhancement of the effect of spin-orbit coupling (SOC) in the Fe-Co-B alloys. First-principles calculations reveal that the increase in orbital magnetic moment mainly originates from B impurities in octahedral position and the reduced symmetry around B atoms. These findings offer the possibility to enhance SOC phenomena-namely the magnetocrystalline anisotropy and the orbital moment-by stabilizing anisotropic strain by doping 4 at.% B. Results on the influence of B doping on the Fe-Co film microstructure, their coercive field and magnetic relaxation are also presented.
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Affiliation(s)
- R Salikhov
- Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany
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4
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Grisolia M, Varignon J, Sanchez-Santolino G, Arora A, Valencia S, Varela M, Abrudan R, Weschke E, Schierle E, Rault J, Rueff JP, Barthélémy A, Santamaria J, Bibes M. Hybridization-controlled charge transfer and induced magnetism at correlated oxide interfaces. Nat Phys 2016; 12:484-492. [PMID: 27158255 PMCID: PMC4856211 DOI: 10.1038/nphys3627] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 12/04/2015] [Indexed: 05/22/2023]
Abstract
At interfaces between conventional materials, band bending and alignment are classically controlled by differences in electrochemical potential. Applying this concept to oxides in which interfaces can be polar and cations may adopt a mixed valence has led to the discovery of novel two-dimensional states between simple band insulators such as LaAlO3 and SrTiO3. However, many oxides have a more complex electronic structure, with charge, orbital and/or spin orders arising from strong Coulomb interactions between transition metal and oxygen ions. Such electronic correlations offer a rich playground to engineer functional interfaces but their compatibility with the classical band alignment picture remains an open question. Here we show that beyond differences in electron affinities and polar effects, a key parameter determining charge transfer at correlated oxide interfaces is the energy required to alter the covalence of the metal-oxygen bond. Using the perovskite nickelate (RNiO3) family as a template, we probe charge reconstruction at interfaces with gadolinium titanate GdTiO3. X-ray absorption spectroscopy shows that the charge transfer is thwarted by hybridization effects tuned by the rare-earth (R) size. Charge transfer results in an induced ferromagnetic-like state in the nickelate, exemplifying the potential of correlated interfaces to design novel phases. Further, our work clarifies strategies to engineer two-dimensional systems through the control of both doping and covalence.
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Affiliation(s)
- M.N. Grisolia
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - J. Varignon
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - G. Sanchez-Santolino
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A. Arora
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - S. Valencia
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - M. Varela
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - R. Abrudan
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - E. Weschke
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - E. Schierle
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - J.E. Rault
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - J.-P. Rueff
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - A. Barthélémy
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - J. Santamaria
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - M. Bibes
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
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Abrudan R, Brüssing F, Salikhov R, Meermann J, Radu I, Ryll H, Radu F, Zabel H. ALICE—An advanced reflectometer for static and dynamic experiments in magnetism at synchrotron radiation facilities. Rev Sci Instrum 2015; 86:063902. [PMID: 26133845 DOI: 10.1063/1.4921716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on significant developments of a high vacuum reflectometer (diffractometer) and spectrometer for soft x-ray synchrotron experiments which allows conducting a wide range of static and dynamic experiments. Although the chamber named ALICE was designed for the analysis of magnetic hetero- and nanostructures via resonant magnetic x-ray scattering, the instrument is not limited to this technique. The versatility of the instrument was testified by a series of pilot experiments. Static measurements involve the possibility to use scattering and spectroscopy synchrotron based techniques (photon-in photon-out, photon-in electron-out, and coherent scattering). Dynamic experiments require either laser or magnetic field pulses to excite the spin system followed by x-ray probe in the time domain from nano- to femtosecond delay times. In this temporal range, the demagnetization/remagnetization dynamics and magnetization precession in a number of magnetic materials (metals, alloys, and magnetic multilayers) can be probed in an element specific manner. We demonstrate here the capabilities of the system to host a variety of experiments, featuring ALICE as one of the most versatile and demanded instruments at the Helmholtz Center in Berlin-BESSY II synchrotron center in Berlin, Germany.
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Affiliation(s)
- R Abrudan
- Institute for Condensed Matter Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - F Brüssing
- Institute for Condensed Matter Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - R Salikhov
- Institute for Condensed Matter Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Meermann
- Institute for Condensed Matter Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - I Radu
- Helmholtz-Zentrum-Berlin for Materials and Energy, 12489 Berlin, Germany
| | - H Ryll
- Helmholtz-Zentrum-Berlin for Materials and Energy, 12489 Berlin, Germany
| | - F Radu
- Helmholtz-Zentrum-Berlin for Materials and Energy, 12489 Berlin, Germany
| | - H Zabel
- Institute for Condensed Matter Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany
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Bruno FY, Grisolia MN, Visani C, Valencia S, Varela M, Abrudan R, Tornos J, Rivera-Calzada A, Ünal AA, Pennycook SJ, Sefrioui Z, Leon C, Villegas JE, Santamaria J, Barthélémy A, Bibes M. Insight into spin transport in oxide heterostructures from interface-resolved magnetic mapping. Nat Commun 2015; 6:6306. [PMID: 25686532 DOI: 10.1038/ncomms7306] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 01/15/2015] [Indexed: 11/09/2022] Open
Abstract
At interfaces between complex oxides, electronic, orbital and magnetic reconstructions may produce states of matter absent from the materials involved, offering novel possibilities for electronic and spintronic devices. Here we show that magnetic reconstruction has a strong influence on the interfacial spin selectivity, a key parameter controlling spin transport in magnetic tunnel junctions. In epitaxial heterostructures combining layers of antiferromagnetic LaFeO(3) (LFO) and ferromagnetic La(0.7)Sr(0.3)MnO(3) (LSMO), we find that a net magnetic moment is induced in the first few unit planes of LFO near the interface with LSMO. Using X-ray photoemission electron microscopy, we show that the ferromagnetic domain structure of the manganite electrodes is imprinted into the antiferromagnetic tunnel barrier, endowing it with spin selectivity. Finally, we find that the spin arrangement resulting from coexisting ferromagnetic and antiferromagnetic interactions strongly influences the tunnel magnetoresistance of LSMO/LFO/LSMO junctions through competing spin-polarization and spin-filtering effects.
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Affiliation(s)
- F Y Bruno
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - M N Grisolia
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - C Visani
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - S Valencia
- Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - M Varela
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain [3] Materials Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R Abrudan
- 1] Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany [2] Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Tornos
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A Rivera-Calzada
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A A Ünal
- Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - S J Pennycook
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Z Sefrioui
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - C Leon
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - J E Villegas
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - J Santamaria
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A Barthélémy
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - M Bibes
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
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Radu I, Stamm C, Eschenlohr A, Radu F, Abrudan R, Vahaplar K, Kachel T, Pontius N, Mitzner R, Holldack K, Föhlisch A, Evans RFL, Ostler TA, Mentink J, Chantrell RW, Tsukamoto A, Itoh A, Kirilyuk A, Kimel AV, Rasing T. Engineering Ultrafast Magnetism. Springer Proceedings in Physics 2015. [DOI: 10.1007/978-3-319-07743-7_92] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Abstract
We investigated magnetic phase transitions, magnetic anisotropy, and magnetic domains in Pd1-xFex alloys with different Fe concentrations x = 2.2-7.2%. The Curie temperature depends linearly on the Fe concentration in the regime studied. The magnetization is dominantly in-plane with a small out-of-plane remanent contribution. Resonant magnetic small angle scattering with circularly polarized x-rays tuned to the L3 resonance edge of Fe revealed a small angle scattering ring corresponding to magnetic domain fluctuations on a length scale of 100 nm. These fluctuations are isotropically distributed in the film plane and appear to have an out-of-plane component. On increasing the transverse coherence of the incident beam, the scattering ring decomposes in a speckle pattern, indicative of magnetic correlations on a length scale smaller than the x-ray coherence length of about 4 μm.
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Affiliation(s)
- M Ewerlin
- Institut für Experimentalphysik/Festkörperphysik, Fakultät für Physik and Astronomie, Ruhr-Universität Bochum, D-44780 Bochum, Germany
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9
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Valencia S, Crassous A, Bocher L, Garcia V, Moya X, Cherifi RO, Deranlot C, Bouzehouane K, Fusil S, Zobelli A, Gloter A, Mathur ND, Gaupp A, Abrudan R, Radu F, Barthélémy A, Bibes M. Interface-induced room-temperature multiferroicity in BaTiO₃. Nat Mater 2011; 10:753-758. [PMID: 21857674 DOI: 10.1038/nmat3098] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 07/12/2011] [Indexed: 05/27/2023]
Abstract
Multiferroic materials possess two or more ferroic orders but have not been exploited in devices owing to the scarcity of room-temperature examples. Those that are ferromagnetic and ferroelectric have potential applications in multi-state data storage if the ferroic orders switch independently, or in electric-field controlled spintronics if the magnetoelectric coupling is strong. Future applications could also exploit toroidal moments and optical effects that arise from the simultaneous breaking of time-reversal and space-inversion symmetries. Here, we use soft X-ray resonant magnetic scattering and piezoresponse force microscopy to reveal that, at the interface with Fe or Co, ultrathin films of the archetypal ferroelectric BaTiO₃ simultaneously possess a magnetization and a polarization that are both spontaneous and hysteretic at room temperature. Ab initio calculations of realistic interface structures provide insight into the origin of the induced moments and bring support to this new approach for creating room-temperature multiferroics.
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Affiliation(s)
- S Valencia
- Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
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10
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Miguel J, Abrudan R, Bernien M, Piantek M, Tieg C, Kirschner J, Kuch W. Magnetic domain coupling study in single-crystalline Fe/CoO bilayers. J Phys Condens Matter 2009; 21:185004. [PMID: 21825450 DOI: 10.1088/0953-8984/21/18/185004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on a study of the magnetic domain coupling in epitaxial wedge-shaped Fe layers deposited onto CoO/Ag(001). By using photoelectron emission microscopy (PEEM) in combination with x-ray magnetic circular and linear dichroism (XMCD, XMLD), we imaged the ferromagnetic and antiferromagnetic domains present in the Fe and CoO layers, respectively, below the CoO magnetic ordering temperature. The uncompensated Co spins at the Fe/CoO interface were revealed by XMCD-PEEM and were found to be coupled parallel to the magnetization of the Fe layer. An increase of the CoO XMLD contrast is visible for Fe thicknesses below 2 ML, where the Fe layer lacks magnetic long-range order.
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Affiliation(s)
- J Miguel
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
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Fodor O, Cotul S, Szantay I, Farcasanu M, Abrudan R, Andrisca E, Mikle J. [Behavior of urinary sulfur metabolites in duodenal and stomach ulcer. Study with methionine S35. Contribution to the physiopathology of peptic ulcer]. Acta Gastroenterol Belg 1966; 29:943-8. [PMID: 5990093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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