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Szpytma M, Ślęzak M, Janus W, Nayyef H, Ślęzak T, Mandziak A, Zając M, Wilgocka-Ślęzak D, Menteş TO, Jugovac M, Locatelli A, Kozioł-Rachwał A. Transfer of magnetic anisotropy in epitaxial Co/NiO/Fe trilayers. Sci Rep 2024; 14:1680. [PMID: 38243038 PMCID: PMC10798992 DOI: 10.1038/s41598-024-51896-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 01/10/2024] [Indexed: 01/21/2024] Open
Abstract
The magnetic properties of Co(10 Å)/NiO(40 Å)/Fe trilayer epitaxially grown on W(110) substrate were investigated with use of x-ray magnetic linear dichroism (XMLD) and x-ray magnetic circular dichroism (XMCD). We showed that magnetic anisotropy of Fe film that can be controlled by a thickness-driven spin reorientation transition is transferred via interfacial exchange coupling not only to NiO layer but further to ferromagnetic Co overlayer as well. Similarly, a temperature driven spin reorientation of Fe sublayer induces a reorientation of NiO spin orientation and simultaneous switching of the Co magnetization direction. Finally, by element specific XMCD and XMLD magnetic hysteresis loop measurements we proved that external magnetic field driven reorientation of Fe and Co magnetizations as well as NiO Néel vector are strictly correlated and magnetic anisotropy fields of Fe and Co sublayers are identical despite the different crystal structures.
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Affiliation(s)
- M Szpytma
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland.
| | - M Ślęzak
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland
| | - W Janus
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland
| | - H Nayyef
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland
| | - T Ślęzak
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland
| | - A Mandziak
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow, Poland
| | - M Zając
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow, Poland
| | - D Wilgocka-Ślęzak
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Krakow, Poland
| | - T O Menteş
- Elettra - Sincrotrone Trieste, Basovizza, Trieste, Italy
| | - M Jugovac
- Elettra - Sincrotrone Trieste, Basovizza, Trieste, Italy
| | - A Locatelli
- Elettra - Sincrotrone Trieste, Basovizza, Trieste, Italy
| | - A Kozioł-Rachwał
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, Krakow, Poland
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2
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Polishchuk DM, Tykhonenko-Polishchuk YO, Lytvynenko YM, Rostas AM, Gomonay OV, Korenivski V. Thermal Gating of Magnon Exchange in Magnetic Multilayers with Antiferromagnetic Spacers. PHYSICAL REVIEW LETTERS 2021; 126:227203. [PMID: 34152170 DOI: 10.1103/physrevlett.126.227203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 03/05/2021] [Accepted: 05/05/2021] [Indexed: 06/13/2023]
Abstract
We observe a strong thermally controlled magnon-mediated interlayer coupling of two ferromagnetic layers via an antiferromagnetic spacer in spin-valve type trilayers. The effect manifests itself as a coherent switching as well as collective resonant precession of the two ferromagnets, which can be controlled by varying temperature and the spacer thickness. We explain the observed behavior as due to a strong hybridization of the ferro- and antiferromagnetic magnon modes in the trilayer at temperatures just below the Néel temperature of the antiferromagnetic spacer.
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Affiliation(s)
- D M Polishchuk
- Nanostructure Physics, Royal Institute of Technology, 10691 Stockholm, Sweden
- Institute of Magnetism of the NAS of Ukraine and MES of Ukraine, 03142 Kyiv, Ukraine
| | - Yu O Tykhonenko-Polishchuk
- Nanostructure Physics, Royal Institute of Technology, 10691 Stockholm, Sweden
- Institute of Magnetism of the NAS of Ukraine and MES of Ukraine, 03142 Kyiv, Ukraine
| | - Ya M Lytvynenko
- Institute of Magnetism of the NAS of Ukraine and MES of Ukraine, 03142 Kyiv, Ukraine
| | - A M Rostas
- National Institute of Materials Physics, 077125 Bucharest-Magurele, Romania
| | - O V Gomonay
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - V Korenivski
- Nanostructure Physics, Royal Institute of Technology, 10691 Stockholm, Sweden
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3
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Probing the Transfer of the Exchange Bias Effect by Polarized Neutron Reflectometry. Sci Rep 2019; 9:6708. [PMID: 31040356 PMCID: PMC6491425 DOI: 10.1038/s41598-019-43251-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 04/11/2019] [Indexed: 11/21/2022] Open
Abstract
The magnetic reversal behavior of a ferromagnet (FM) coupled through an FeMn antiferromagnet (AF) to a pinned ferromagnet has been investigated by polarized neutron reflectivity measurements. With FeMn as the AF layer it is found that there exists 90° interlayer coupling through this layer and that this plays a key role in the transfer of the exchange bias (EB) effect from the FM/AF interface to the AF/pinned-FM interface. Combined with Monte Carlo simulations, we demonstrate that the competition between the interlayer coupling and the anisotropy of the AF layer results in a control of the EB effect which has potential for device applications.
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4
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Anomalous Hall-like effect probe of antiferromagnetic domain wall. Sci Rep 2018; 8:329. [PMID: 29321481 PMCID: PMC5762948 DOI: 10.1038/s41598-017-18514-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/13/2017] [Indexed: 11/08/2022] Open
Abstract
Of crucial importance to antiferromagnetic (AF) spintronic devices, AF domain wall (AFDW), created in exchange biased Y3Fe5O12/Ni0.50Co0.50O (NiCoO)/Pt, is characterized by anomalous Hall-like effect through magnetic proximity effect and spin Hall magnetoresistance at NiCoO/Pt interface. The AFDW thickness, in the order of nanometers, has been for the first time proved in experiments to increase with increasing temperature. AF spins within AFDW show the same chirality in decent and ascent branches of ferromagnetic magnetization reversal process. Moreover, the uncompensated magnetic moment at the NiCoO/Pt interface is of perpendicular magnetization anisotropy and changes linearly in magnitude with temperature due to the reduced coordination of the magnetic atoms on the AF surface. This work will help to clarify the mechanism of the spin current propagation in AF materials and fully understand the physics behind exchange bias.
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5
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Li J, Tan A, Ma S, Yang RF, Arenholz E, Hwang C, Qiu ZQ. Chirality switching and winding or unwinding of the antiferromagnetic NiO domain walls in Fe/NiO/Fe/CoO/Ag(001). PHYSICAL REVIEW LETTERS 2014; 113:147207. [PMID: 25325659 DOI: 10.1103/physrevlett.113.147207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Indexed: 06/04/2023]
Abstract
Fe/NiO/Fe/CoO/Ag(001) single crystalline films were grown epitaxially and investigated by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. The bottom Fe layer magnetization is pinned through exchange coupling to the CoO layer and the top Fe layer magnetization can be rotated by an in-plane external magnetic field. We find that the NiO spins wind up to form a domain wall due to the perpendicular NiO/Fe interfacial coupling as the top layer Fe magnetization rotates from 0° to 90°, but switch wall chirality and unwind the wall as the Fe magnetization rotates from 90° to 180°. This observation shows that Mauri's 180° domain wall does not exist in perpendicularly coupled ferromagnetic-antiferromagnetic systems in the strong coupling regime.
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Affiliation(s)
- J Li
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - A Tan
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - S Ma
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA and Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - R F Yang
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - E Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - 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, USA
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6
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Ke X, Belenky LJ, Lauter V, Ambaye H, Bark CW, Eom CB, Rzchowski MS. Spin structure in an interfacially coupled epitaxial ferromagnetic oxide heterostructure. PHYSICAL REVIEW LETTERS 2013; 110:237201. [PMID: 25167526 DOI: 10.1103/physrevlett.110.237201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Indexed: 06/03/2023]
Abstract
We report the spin structure of an exchange-biased ferromagnetic oxide heterostructure, La(0.67)Sr(0.33)MnO(3)/SrRuO(3), through magnetization and polarized neutron reflectometry measurements. We reveal that the magnetization reversal process of the La(0.67)Sr(0.33)MnO(3) biased layer critically depends on the frozen-in spin structure of the SrRuO(3) biasing layer during the cooling process. Furthermore, we observe unexpected double-shifted hysteresis loops of the biased layer that originates from the formation of lateral 180° magnetic domains within the biasing layer, a new mechanism not found in conventional exchange-bias systems.
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Affiliation(s)
- X Ke
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - L J Belenky
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - V Lauter
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H Ambaye
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C W Bark
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C B Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M S Rzchowski
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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7
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Tveten EG, Qaiumzadeh A, Tretiakov OA, Brataas A. Staggered dynamics in antiferromagnets by collective coordinates. PHYSICAL REVIEW LETTERS 2013; 110:127208. [PMID: 25166843 DOI: 10.1103/physrevlett.110.127208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Indexed: 06/03/2023]
Abstract
Antiferromagnets can be used to store and manipulate spin information, but the coupled dynamics of the staggered field and the magnetization are very complex. We present a theory which is conceptually much simpler and which uses collective coordinates to describe staggered field dynamics in antiferromagnetic textures. The theory includes effects from dissipation, external magnetic fields, as well as reactive and dissipative current-induced torques. We conclude that, at low frequencies and amplitudes, currents induce collective motion by means of dissipative rather than reactive torques. The dynamics of a one-dimensional domain wall, pinned at 90° at its ends, are described as a driven harmonic oscillator with a natural frequency inversely proportional to the length of the texture.
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Affiliation(s)
- Erlend G Tveten
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Alireza Qaiumzadeh
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - O A Tretiakov
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, USA
| | - Arne Brataas
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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8
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Yue L, Li Z, Kirby R, Sellmyer D. MFM studies of interlayer exchange coupling in Co/Ru/Co films: Effect of Ru layer thickness. Ultramicroscopy 2009; 109:1040-3. [DOI: 10.1016/j.ultramic.2009.03.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Morales R, Li ZP, Olamit J, Liu K, Alameda JM, Schuller IK. Role of the antiferromagnetic bulk spin structure on exchange bias. PHYSICAL REVIEW LETTERS 2009; 102:097201. [PMID: 19392557 DOI: 10.1103/physrevlett.102.097201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Revised: 10/28/2008] [Indexed: 05/27/2023]
Abstract
The cooling field dependence of the exchange bias field in ferromagnet/antiferromagnet (FM/AF) multilayers demonstrates that the bulk AF spin structure plays a crucial role on the origin of exchange bias. FM/AF/FM trilayers were designed to eliminate any interlayer exchange coupling between the FM slabs. By choosing the magnetic cooling field, the AF is ordered below its Néel temperature with the FM layers fully saturated either parallel or antiparallel to each other. The significant difference in the exchange bias field between these two cooling configurations confirms that exchange bias cannot be a purely interfacial effect and that the bulk AF moments play a significant role in pinning the uncompensated spins at the AF/FM interface. This experiment also demonstrates that the mechanism responsible for coercivity enhancement has a different origin and is independent of the process that gives rise to exchange bias.
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Affiliation(s)
- R Morales
- Physics Department, University of California-San Diego, La Jolla, California 92093, USA
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10
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Gao TR, Yang DZ, Zhou SM, Chantrell R, Asselin P, Du J, Wu XS. Hysteretic behavior of angular dependence of exchange bias in FeNi/FeMn bilayers. PHYSICAL REVIEW LETTERS 2007; 99:057201. [PMID: 17930782 DOI: 10.1103/physrevlett.99.057201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2006] [Indexed: 05/25/2023]
Abstract
For FeNi/FeMn bilayers, the angular dependence of exchange bias shows hysteresis between clockwise and counterclockwise rotations, as a new signature. The hysteresis decreases for thick antiferromagnet layers. Calculations have clearly shown that the orientation of antiferromagnet spins also exhibits hysteresis between clockwise and counterclockwise rotations. This furnishes an interpretation of the macroscopic behavior of the ferromagnetic layer in terms of the thermally driven evolution of the magnetic state of the antiferromagnet layer.
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Affiliation(s)
- T R Gao
- The State Key Lab for Advanced Photonic Materials Devices, Fudan University, Shanghai 200433, China
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11
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Blamire MG, Ali M, Leung CW, Marrows CH, Hickey BJ. Exchange bias and blocking temperature in Co/FeMn/CuNi trilayers. PHYSICAL REVIEW LETTERS 2007; 98:217202. [PMID: 17677802 DOI: 10.1103/physrevlett.98.217202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Indexed: 05/16/2023]
Abstract
Aspects of exchange bias between antiferromagnets and ferromagnets remain unclear despite recent research. An outstanding issue is the relationship between exchange bias and enhanced coercivity in the ferromagnetic layer. This Letter reports the unexpected finding that a substantial exchange bias can be generated between an antiferromagnet (FeMn) with a higher ordering temperature than that of the ferromagnet (CuNi). We interpret the result in terms of a temperature-dependent competition between interfacial exchange and antiferromagnet anisotropy energies. Crossover of these energies during cooling is responsible for the onset of exchange bias at the blocking temperature.
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Affiliation(s)
- M G Blamire
- Department of Materials Science, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom
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12
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Kuch W, Chelaru LI, Offi F, Wang J, Kotsugi M, Kirschner J. Three-dimensional noncollinear antiferromagnetic order in single-crystalline FeMn ultrathin films. PHYSICAL REVIEW LETTERS 2004; 92:017201. [PMID: 14754014 DOI: 10.1103/physrevlett.92.017201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Indexed: 05/24/2023]
Abstract
We present experimental evidence for a three-dimensional noncollinear antiferromagnetic spin structure in ultrathin single-crystalline fcc Fe50Mn50 layers using magnetic circular dichroism photoelectron emission microscopy and x-ray magnetic linear dichroism. Layer-resolved as-grown domain images of epitaxial trilayers grown on Cu(001) in which FeMn is sandwiched between ferromagnetic layers with different easy axes reveal the presence of antiferromagnetic spin components in the film plane and normal to the film plane. An FeMn spin structure with no collinear order in the film plane is consistent with the absence of x-ray magnetic linear dichroism in Fe L3 absorption in FeMn/Co bilayers.
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Affiliation(s)
- Wolfgang Kuch
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
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13
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Altieri S, Finazzi M, Hsieh HH, Lin HJ, Chen CT, Hibma T, Valeri S, Sawatzky GA. Magnetic dichroism and spin structure of antiferromagnetic NiO(001) films. PHYSICAL REVIEW LETTERS 2003; 91:137201. [PMID: 14525332 DOI: 10.1103/physrevlett.91.137201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2002] [Indexed: 05/24/2023]
Abstract
We find that Ni L2 edge x-ray magnetic linear dichroism is fully reversed for NiO(001) films on materials with reversed lattice mismatch. We relate this phenomenon to a preferential stabilization of magnetic S domains with main spin component either in or out of the plane, via dipolar interactions. This suggests a way to selectively control spin structures in 3d systems with small spin-orbit coupling.
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Affiliation(s)
- S Altieri
- INFM-National Center on Nanostructures and Biosystems at Surfaces (S3), via G. Campi 213/A, I-41100 Modena, Italy
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14
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Camarero J, Pennec Y, Vogel J, Bonfim M, Pizzini S, Ernult F, Fettar F, Garcia F, Lançon F, Billard L, Dieny B, Tagliaferri A, Brookes NB. Perpendicular interlayer coupling in Ni80Fe20/NiO/Co trilayers. PHYSICAL REVIEW LETTERS 2003; 91:027201. [PMID: 12906504 DOI: 10.1103/physrevlett.91.027201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Indexed: 05/24/2023]
Abstract
An in-plane perpendicular magnetic coupling between Ni80Fe20 and Co has been found in NiFe/NiO/Co trilayers for a NiO thickness ranging from 4 to 25 nm by magneto-optical Kerr effect and x-ray magnetic circular dichroism measurements. In the easy magnetization direction of the Co layer, the Co coercive field H(C) increases when the thickness of the NiO layer t(NiO) increases. Because of the coupling, H(C) is always larger than for NiO/Co bilayers with the same thicknesses. The saturation field of the NiFe layer H(S) decreases when t(NiO) increases, indicating a weakening of the coupling. Numerical simulations show that the presence of interface roughness combined with a small value of the NiO anisotropy can explain the observed 90 degrees coupling.
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Affiliation(s)
- J Camarero
- Laboratoire Louis Néel, CNRS, BP166, 38042 Grenoble Cedex, France.
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15
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Steadman P, Ali M, Hindmarch AT, Marrows CH, Hickey BJ, Langridge S, Dalgliesh RM, Foster S. Exchange bias in spin-engineered double superlattices. PHYSICAL REVIEW LETTERS 2002; 89:077201. [PMID: 12190551 DOI: 10.1103/physrevlett.89.077201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2002] [Indexed: 05/23/2023]
Abstract
Exchange bias has been observed in sputtered magnetic double superlattices which consist of a ferromagnetically coupled superlattice grown on an antiferromagnetically (AF) coupled superlattice. This system exhibits a parallel domain wall, a spin flop transition, and exchange bias when the anisotropy is large in the AF block. This work shows that neither the domain wall nor the spin flop are directly related to exchange bias but that the anisotropy is essential.
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Affiliation(s)
- P Steadman
- Department of Physics and Astronomy, E. C. Stoner Laboratory, University of Leeds, United Kingdom.
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16
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Zhu W, Seve L, Sears R, Sinkovic B, Parkin SS. Field cooling induced changes in the antiferromagnetic structure of NiO films. PHYSICAL REVIEW LETTERS 2001; 86:5389-5392. [PMID: 11384505 DOI: 10.1103/physrevlett.86.5389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2000] [Indexed: 05/23/2023]
Abstract
The magnetic anisotropy in antiferromagnetic 500 A thick NiO films, before and after the establishment of an exchange bias field with Co84Fe16 ferromagnetic layers, was measured using magnetic linear dichroism in soft x-ray absorption. Both <111> textured NiO and untextured NiO films show exchange-bias induced in-plane magnetic anisotropy of nearly equal magnitude and with the Ni moment axis being nearly parallel to the exchange bias field direction. These results represent the first observation of the key step in the exchange biasing process, namely, repopulation of the antiferromagnetic domains whose magnetization axis is closest to the exchange bias field direction.
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Affiliation(s)
- W Zhu
- Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut 06269, USA
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