The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Guus Rijnders - One of the best experts on this subject based on the ideXlab platform.
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Uniaxial Magnetic Anisotropy induced low field anomalous anisotropic magnetoresistance in manganite thin films
APL Materials, 2014Co-Authors: Zhaoliang Liao, Mark Huijben, Gertjan Koster, Guus RijndersAbstract:La2/3Sr1/3MnO3 films with Uniaxial Magnetic Anisotropy were coherently grown on NdGaO3 (110) substrates. The Uniaxial Anisotropy has strong effect on magnetoresistance (MR). A positive MR was observed when the current is along Magnetic easy axis under the current-field perpendicular geometry. In contrast, no positive MR is observed when current is along the Magnetic hard axis regardless of the field direction. Our analysis indicates that the anomalous anisotropic MR effect arises from the Uniaxial Magnetic Anisotropy caused stripe domains which contribute to strong anisotropic domain wall resistivity.
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Magnetic oxide nanowires with strain-controlled Uniaxial Magnetic Anisotropy direction
Physical Review B, 2009Co-Authors: M. Mathews, Guus Rijnders, Ron Jansen, J.c. Lodder, David H.a. BlankAbstract:While Magnetic nanowires generally have a preferential magnetization direction along the wire axis to minimize magnetostatic energy, it is shown here for epitaxial Magnetic oxide nanowires that substrate-induced strain can be used to tailor the Magnetic easy axis in any direction. La0.67Sr0.33MnO3 (LSMO) nanowires were prepared by pulsed laser deposition of LSMO thin films on NdGaO3 (NGO) substrates of two different orientations [NGO(110)o and NGO(010)o], followed by patterning into arrays of nanowires by laser interference lithography. The Uniaxial compressive strain from the substrate induces a strong Uniaxial Magnetic Anisotropy in the LSMO that dominates the Anisotropy. Hence, one obtains LSMO nanowires having a Magnetic easy axis that can lie in any direction, including perpendicular to the wire axis. In marked contrast, similar nanowires on SrTiO3(001) substrates without significant Uniaxial strain exhibit the usual preferential magnetization direction along the wire axis, as dictated by magnetostatic shape Anisotropy. The tunable Magnetic Anisotropy direction is a useful feature for applications of Magnetic nanowires in Magnetic memory, sensor, and logic devices.
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Step-induced Uniaxial Magnetic Anisotropy of La0:67Sr0:33MnO3 thin films
Applied Physics Letters, 2005Co-Authors: M. Mathews, Guus Rijnders, Ferry M. Postma, J. Cock Lodder, Ron Jansen, Dave H.a. BlankAbstract:The Magnetic Anisotropy of epitaxial La0.67 Sr0.33 MnO3 (LSMO) thin films on vicinal, TiO2 -terminated SrTiO3 substrates is investigated. Atomic force microscopy shows a regular step-terrace structure on the LSMO surface which is a replication of the surface of the substrate. The films show in-plane Uniaxial Magnetic Anisotropy at room temperature, with the easy axis along the step direction. At low temperature the films show biaxial crystalline Anisotropy with easy axes along [110], and hard axes along the [100] direction of LSMO. © 2005 American Institute of Physics
Junling Wang - One of the best experts on this subject based on the ideXlab platform.
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Origin of the Uniaxial Magnetic Anisotropy in La0.7Sr0.3MnO3on stripe-domain BiFeO3
Physical Review B, 2013Co-Authors: Lu You, Baomin Wang, Xi Zou, Zhi Shiuh Lim, Yang Zhou, Hui Ding, Lang Chen, Junling WangAbstract:The La0.7Sr0.3MnO3/BiFeO3 (LSMO/BFO) heterostructure has been a model system to study the interaction between ferroic order parameters at a complex oxide interface. In this study, Uniaxial Magnetic Anisotropy is artificially induced in LSMO thin film grown on BFO with electrically patterned stripe domains. Variable-field Magnetic force microscopy is exploited to investigate the in situ Magnetic switching dynamics and subsequently determine the Magnetic easy axis of the LSMO thin film. Intriguingly, one-to-one correspondence between the magnetization of LSMO and the polarization of BFO is found. The observed Uniaxial Magnetic Anisotropy is attributed to the magnetocrystalline Anisotropy of the LSMO, which is induced by the shear strain of the BFO lattice, rather than the interfacial Magnetic coupling which would be more naturally assumed. This finding highlights the crucial role of lattice coupling at a complex oxide interface. When multiple-order parameters come into play at the heterointerface, special care is needed to deconvolute their effects on the related physical properties.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)Published versio
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origin of the Uniaxial Magnetic Anisotropy in la0 7sr0 3mno3on stripe domain bifeo3
Physical Review B, 2013Co-Authors: Junling WangAbstract:he La0.7Sr0.3MnO3/BiFeO3 (LSMO/BFO) heterostructure has been a model system to study the interaction between ferroic order parameters at a complex oxide interface. In this study, Uniaxial Magnetic Anisotropy is artificially induced in LSMO thin film grown on BFO with electrically patterned stripe domains. Variable-field Magnetic force microscopy is exploited to investigate thein situMagnetic switching dynamics and subsequently determine the Magnetic easy axis of the LSMO thin film. Intriguingly, one-to-one correspondence between the magnetization of LSMO and the polarization of BFO is found. The observed Uniaxial Magnetic Anisotropy is attributed to the magnetocrystalline Anisotropy of the LSMO, which is induced by the shear strain of the BFO lattice, rather than the interfacial Magnetic coupling which would be more naturally assumed. This finding highlights the crucial role of lattice coupling at a complex oxide interface. When multiple-order parameters come into play at the heterointerface, special care is needed to deconvolute their effects on the related physical properties.
Jeffrey Mccord - One of the best experts on this subject based on the ideXlab platform.
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The role of Uniaxial Magnetic Anisotropy distribution on domain wall tilting in amorphous glass-coated microwires
Journal of Applied Physics, 2020Co-Authors: Kornel Richter, Andre Thiaville, Rastislav Varga, Jeffrey MccordAbstract:Magnetic properties of highly magnetostrictive amorphous glass-coated microwires are strongly correlated to the presence of a glass coating that introduces a spatially inhomogeneous stress field distribution. We investigate the influence of mechanical stresses on the inclination of Magnetic domain walls in Magnetic microwires. Magneto-optical Kerr effect imaging is used to compare the tilted orientation of the domain wall shape in as-cast and annealed microwires. Angular dependencies of magnetization loops measured by alternating gradient field magnetometry reveal that the change of domain wall tilting with annealing is related to the decrease of a Magnetic Anisotropy with axial orientation. Finally, microMagnetic simulations are used to show that sufficiently high Uniaxial Magnetic Anisotropy gives rise to the presence of the observed charged domain walls with tilted orientation.
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The role of Uniaxial Magnetic Anisotropy distribution on domain wall tilting in amorphous glass-coated microwires
Journal of Applied Physics, 2020Co-Authors: Kornel Richter, Andre Thiaville, Rastislav Varga, Jeffrey MccordAbstract:Magnetic properties of highly magnetostrictive amorphous glass-coated microwires are strongly correlated to the presence of a glass coating that introduces a spatially inhomogeneous stress field distribution. We investigate the influence of mechanical stresses on the inclination of Magnetic domain walls in Magnetic microwires. Magneto-optical Kerr effect imaging is used to compare the tilted orientation of the domain wall shape in as-cast and annealed microwires. Angular dependencies of magnetization loops measured by alternating gradient field magnetometry reveal that the change of domain wall tilting with annealing is related to the decrease of Magnetic Anisotropy with axial orientation. Finally, microMagnetic simulations are used to show that sufficiently high Uniaxial Magnetic Anisotropy gives rise to the presence of observed charged domain walls with tilted orientation.
M. Mathews - One of the best experts on this subject based on the ideXlab platform.
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Magnetic oxide nanowires with strain-controlled Uniaxial Magnetic Anisotropy direction
Physical Review B, 2009Co-Authors: M. Mathews, Guus Rijnders, Ron Jansen, J.c. Lodder, David H.a. BlankAbstract:While Magnetic nanowires generally have a preferential magnetization direction along the wire axis to minimize magnetostatic energy, it is shown here for epitaxial Magnetic oxide nanowires that substrate-induced strain can be used to tailor the Magnetic easy axis in any direction. La0.67Sr0.33MnO3 (LSMO) nanowires were prepared by pulsed laser deposition of LSMO thin films on NdGaO3 (NGO) substrates of two different orientations [NGO(110)o and NGO(010)o], followed by patterning into arrays of nanowires by laser interference lithography. The Uniaxial compressive strain from the substrate induces a strong Uniaxial Magnetic Anisotropy in the LSMO that dominates the Anisotropy. Hence, one obtains LSMO nanowires having a Magnetic easy axis that can lie in any direction, including perpendicular to the wire axis. In marked contrast, similar nanowires on SrTiO3(001) substrates without significant Uniaxial strain exhibit the usual preferential magnetization direction along the wire axis, as dictated by magnetostatic shape Anisotropy. The tunable Magnetic Anisotropy direction is a useful feature for applications of Magnetic nanowires in Magnetic memory, sensor, and logic devices.
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Step-induced Uniaxial Magnetic Anisotropy of La0:67Sr0:33MnO3 thin films
Applied Physics Letters, 2005Co-Authors: M. Mathews, Guus Rijnders, Ferry M. Postma, J. Cock Lodder, Ron Jansen, Dave H.a. BlankAbstract:The Magnetic Anisotropy of epitaxial La0.67 Sr0.33 MnO3 (LSMO) thin films on vicinal, TiO2 -terminated SrTiO3 substrates is investigated. Atomic force microscopy shows a regular step-terrace structure on the LSMO surface which is a replication of the surface of the substrate. The films show in-plane Uniaxial Magnetic Anisotropy at room temperature, with the easy axis along the step direction. At low temperature the films show biaxial crystalline Anisotropy with easy axes along [110], and hard axes along the [100] direction of LSMO. © 2005 American Institute of Physics
Osamu Kitakami - One of the best experts on this subject based on the ideXlab platform.
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Magnetic properties of thin hard/soft-stacked dot arrays with a large Uniaxial Magnetic Anisotropy
Journal of Applied Physics, 2009Co-Authors: K. Mitsuzuka, Takehito Shimatsu, Osamu Kitakami, Hiroaki Muraoka, Nobuaki Kikuchi, Hajime AoiAbstract:Magnetic properties of hard/soft stacked dot arrays consisting of thin Co/Pt superlattice hard layers (3.6 nm in thickness, Uniaxial Magnetic Anisotropy, Ku=1.3×107 erg/cm3) and Co soft layers, with dot diameters of 30–40 nm, were investigated as functions of Co soft layer thickness and the interfacial exchange coupling between the hard and soft layers. Pt was used as the control layer of the interfacial exchange coupling, and Co soft layers were sandwiched with Pt layers to induce surface Anisotropy on the Co soft layers. The remanence coercivity, Hr, was 2.7 kOe for Co/Pt(3.6 nm)/Co(4 nm) stacked dot arrays and 3.2 kOe for Co/Pt(3.6 nm)/Pt(1.2 nm)/Co(3 nm) stacked dot arrays, and these values were less than half that of single hard layer dot arrays (7.1 kOe). Hr was nearly constant in the ϕ range from 0° to about 45° (ϕ is the applied field angle from the easy axis), and increased significantly as ϕ increased further, as theoretically predicted. Hard/soft dot arrays maintained a relatively large Ku due ...
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Large Uniaxial Magnetic Anisotropy of Co–Pt Perpendicular Films Induced by Lattice Deformation
IEEE Transactions on Magnetics, 2007Co-Authors: Takehito Shimatsu, Y. Okazaki, Hiroki Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroaki Muraoka, Yoshihisa NakamuraAbstract:A study of the thickness dependence of the Uniaxial Magnetic Anisotropy Ku of Co-Pt perpendicular films deposited on Ru seed layers was extended over a wide range of Pt content from 10 to 30 at%, to further investigate the origin of the significant increase in K u on reducing the film thickness, which was previously reported for Co80Pt20/Ru films. Ku increased significantly as the thickness decreased in all series of films with various Pt content. The rate of increase of Ku with reducing thickness became increasingly large as the Pt content decreased. It should be noted that the Ku of 2-nm-thick films was an almost constant 2times107 erg/cm3 over the range of Pt contents studied, although Ku was maximized at 25-30at%Pt content for films thicker than 5 nm. Experimental results suggest that the increase in Ku on reducing the thickness was mostly related to a reduction of the hcp Co-Pt lattice c/a ratio
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large Uniaxial Magnetic Anisotropy by lattice deformation in copt ru perpendicular films
Journal of Applied Physics, 2006Co-Authors: Takehito Shimatsu, Y. Okazaki, Hiroki Sato, Satoshi Okamoto, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Osamu KitakamiAbstract:A large Uniaxial Magnetic Anisotropy Ku of about 2×107erg∕cm3 was obtained in Co–(20–30) at. % Pt perpendicular films deposited on Ru seed layers. The films showed good c-axis orientation perpendicular to the film plane, and no evidence of a Co3Pt-type-ordered structure was found in the X-ray-diffraction patterns. The value of Ku (the sum of the first- and second-order terms of Uniaxial Anisotropy, Ku1 and Ku2) increased as the thickness of the CoPt layer decreased, and reached about 2×107erg∕cm3 at 2 nm (Co–20 at. % Pt films) or 5 nm (Co–(25–30) at. % Pt films). The ratio of Ku2 to Ku1 was 0.16 in 40 nm films, but reduced to less than 0.03 for thicknesses below 5 nm. The experimental results suggest that, besides the surface Anisotropy, the increase in Ku on reducing the thickness is mostly related to the reduction of the hcp-CoPt lattice c∕a ratio, probably due to epitaxial growth of CoPt on the Ru seed layer.
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Large Uniaxial Magnetic Anisotropy by lattice deformation in CoPt∕Ru perpendicular films
Journal of Applied Physics, 2006Co-Authors: Takehito Shimatsu, Y. Okazaki, Hiroki Sato, Satoshi Okamoto, Hajime Aoi, Hiroaki Muraoka, Yasuaki Nakamura, Osamu KitakamiAbstract:A large Uniaxial Magnetic Anisotropy Ku of about 2×107erg∕cm3 was obtained in Co–(20–30) at. % Pt perpendicular films deposited on Ru seed layers. The films showed good c-axis orientation perpendicular to the film plane, and no evidence of a Co3Pt-type-ordered structure was found in the X-ray-diffraction patterns. The value of Ku (the sum of the first- and second-order terms of Uniaxial Anisotropy, Ku1 and Ku2) increased as the thickness of the CoPt layer decreased, and reached about 2×107erg∕cm3 at 2 nm (Co–20 at. % Pt films) or 5 nm (Co–(25–30) at. % Pt films). The ratio of Ku2 to Ku1 was 0.16 in 40 nm films, but reduced to less than 0.03 for thicknesses below 5 nm. The experimental results suggest that, besides the surface Anisotropy, the increase in Ku on reducing the thickness is mostly related to the reduction of the hcp-CoPt lattice c∕a ratio, probably due to epitaxial growth of CoPt on the Ru seed layer.
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Large Uniaxial Magnetic Anisotropy in Co100-XPtX/Ru Disordered Perpendicular Films
INTERMAG 2006 - IEEE International Magnetics Conference, 2006Co-Authors: Takehito Shimatsu, Y. Okazaki, Hiroki Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroaki Muraoka, Yoshihisa NakamuraAbstract:In this paper, the thickness dependence of Uniaxial Magnetic Anisotropy (Ku) for series of disordered perpendicular CoPt films with 10, 14, 20, 25 and 30 at% Pt content was examined. Ku value as a function of lattice deformation and surface Anisotropy was also discussed.
