The Experts below are selected from a list of 2448 Experts worldwide ranked by ideXlab platform
Ho Nyung Lee - One of the best experts on this subject based on the ideXlab platform.
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symmetry driven atomic rearrangement at a Brownmillerite perovskite interface
Advanced electronic materials, 2016Co-Authors: Tricia L. Meyer, Hyoungjeen Jeen, Xiang Gao, Jonathan R. Petrie, Matthew F. Chisholm, Ho Nyung LeeAbstract:To those investigating new interfacial phenomena, symmetry mismatch is of immense interest. The interfacial and bulk microstructure of the Brownmillerite–perovskite interface is probed using detailed transmission electron microscopy. Unique asymmetric displacements of the tetrahedra at the interface are observed, signifying a compensation mechanism for lattice and symmetry mismatch at the interface.
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Symmetry‐Driven Atomic Rearrangement at a Brownmillerite–Perovskite Interface
Advanced Electronic Materials, 2015Co-Authors: Tricia L. Meyer, Hyoungjeen Jeen, Xiang Gao, Jonathan R. Petrie, Matthew F. Chisholm, Ho Nyung LeeAbstract:To those investigating new interfacial phenomena, symmetry mismatch is of immense interest. The interfacial and bulk microstructure of the Brownmillerite–perovskite interface is probed using detailed transmission electron microscopy. Unique asymmetric displacements of the tetrahedra at the interface are observed, signifying a compensation mechanism for lattice and symmetry mismatch at the interface.
Qinghua Zhang - One of the best experts on this subject based on the ideXlab platform.
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Symmetry mismatch-driven perpendicular magnetic anisotropy for perovskite/Brownmillerite heterostructures
Nature communications, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Grouping different transition metal oxides together by interface engineering is an important route toward emergent phenomenon. While most of the previous works focused on the interface effects in perovskite/perovskite heterostructures, here we reported on a symmetry mismatch-driven spin reorientation toward perpendicular magnetic anisotropy in perovskite/Brownmillerite heterostructures, which is scarcely seen in tensile perovskite/perovskite heterostructures. We show that alternately stacking perovskite La2/3Sr1/3MnO3 and Brownmillerite LaCoO2.5 causes a strong interface reconstruction due to symmetry discontinuity at interface: neighboring MnO6 octahedra and CoO4 tetrahedra at the perovskite/Brownmillerite interface cooperatively relax in a manner that is unavailable for perovskite/perovskite interface, leading to distinct orbital reconstructions and thus the perpendicular magnetic anisotropy. Moreover, the perpendicular magnetic anisotropy is robust, with an anisotropy constant two orders of magnitude greater than the in-plane anisotropy of the perovskite/perovskite interface. The present work demonstrates the great potential of symmetry engineering in designing artificial materials on demand.
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symmetry mismatch driven perpendicular magnetic anisotropy for perovskite Brownmillerite heterostructures
Nature Communications, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Grouping different transition metal oxides together by interface engineering is an important route toward emergent phenomenon. While most of the previous works focused on the interface effects in perovskite/perovskite heterostructures, here we reported on a symmetry mismatch-driven spin reorientation toward perpendicular magnetic anisotropy in perovskite/Brownmillerite heterostructures, which is scarcely seen in tensile perovskite/perovskite heterostructures. We show that alternately stacking perovskite La2/3Sr1/3MnO3 and Brownmillerite LaCoO2.5 causes a strong interface reconstruction due to symmetry discontinuity at interface: neighboring MnO6 octahedra and CoO4 tetrahedra at the perovskite/Brownmillerite interface cooperatively relax in a manner that is unavailable for perovskite/perovskite interface, leading to distinct orbital reconstructions and thus the perpendicular magnetic anisotropy. Moreover, the perpendicular magnetic anisotropy is robust, with an anisotropy constant two orders of magnitude greater than the in-plane anisotropy of the perovskite/perovskite interface. The present work demonstrates the great potential of symmetry engineering in designing artificial materials on demand.
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Symmetry mismatch-driven perpendicular magnetic anisotropy for perovskite/Brownmillerite heterostructures
Nature Publishing Group, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Complex oxide heterostructures exhibit multifunctional behaviour that could be used in a range of device applications. Here, the authors observe that reconstruction at oxide perovskite/Brownmillerite interfaces leads to perpendicular magnetic spin orientation, with potential use in spintronic devices
Chris D. Ling - One of the best experts on this subject based on the ideXlab platform.
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comment on structural and mossbauer study of the Brownmillerite oxides lasrmn2 xfexo5 0 x 0 5
Journal of Alloys and Compounds, 2014Co-Authors: Josie E. Auckett, Chris D. LingAbstract:Abstract Mohamed et al. recently reported in this Journal on the synthesis and characterisation of a series of oxides described as “LaSrMn 2− x Fe x O 5 ”. On the basis of Rietveld refinements against powder X-ray diffraction data, the authors stated that all synthesised members of the series crystallised in the Brownmillerite structure with Pnma symmetry. However, the diffraction patterns presented in that paper clearly correspond to oxidised perovskite phases with small orthorhombic distortions, rather than Brownmillerites. This is consistent with the authors’ failure to report having performed any reaction steps under reducing conditions, as is normally required to obtain the mixed +2/+3 oxidation state of Mn and Fe in the expected Brownmillerites. The materials synthesised under the reported conditions were most likely to have been oxidised pseudo-cubic perovskites LaSrMn 2− x Fe x O 6− δ ( δ ≪ 1), which is consistent with their reported X-ray diffraction data. The interpretation of Mossbauer data in the original paper is therefore flawed.
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Comment on “Structural and Mössbauer study of the Brownmillerite oxides LaSrMn2−xFexO5 (0 ⩽ x ⩽ 0.5)”
Journal of Alloys and Compounds, 2014Co-Authors: Josie E. Auckett, Chris D. LingAbstract:Abstract Mohamed et al. recently reported in this Journal on the synthesis and characterisation of a series of oxides described as “LaSrMn 2− x Fe x O 5 ”. On the basis of Rietveld refinements against powder X-ray diffraction data, the authors stated that all synthesised members of the series crystallised in the Brownmillerite structure with Pnma symmetry. However, the diffraction patterns presented in that paper clearly correspond to oxidised perovskite phases with small orthorhombic distortions, rather than Brownmillerites. This is consistent with the authors’ failure to report having performed any reaction steps under reducing conditions, as is normally required to obtain the mixed +2/+3 oxidation state of Mn and Fe in the expected Brownmillerites. The materials synthesised under the reported conditions were most likely to have been oxidised pseudo-cubic perovskites LaSrMn 2− x Fe x O 6− δ ( δ ≪ 1), which is consistent with their reported X-ray diffraction data. The interpretation of Mossbauer data in the original paper is therefore flawed.
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Combined Experimental and Computational Study of Oxide Ion Conduction Dynamics in Sr2Fe2O5 Brownmillerite
Chemistry of Materials, 2013Co-Authors: Josie E. Auckett, Andrew J. Studer, Eric Pellegrini, Jacques Ollivier, Mark R. Johnson, Helmut Schober, Wojciech Miiller, Chris D. LingAbstract:We report a detailed study of the dynamics of oxide ionic conduction in Brownmillerite-type Sr2Fe2O5, including lattice anisotropy, based on neutron scattering studies of a large (partially twinned...
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Magnetic structure of Sr2Fe2O5 Brownmillerite by single-crystal Mössbauer spectroscopy
Journal of Solid State Chemistry, 2013Co-Authors: João C. Waerenborgh, Josie E. Auckett, Chris D. Ling, Ekaterina V. Tsipis, Vladislav V. KhartonAbstract:In order to determine orientation of the Fe3+ magnetic moments and electric field gradient (efg) axes in the Brownmillerite-type strontium ferrite structure for both iron sublattices where the efg tensor is not axially symmetric, the Mossbauer spectra of powdered and oriented single-crystal Sr2Fe2O5 were analyzed by solving the complete Hamiltonian for hyperfine interactions in the excited and ground states of the 57Fe nuclei. The magnetic moments of both octahedrally and tetrahedrally coordinated iron cations lie on the ac-plane of the orthorhombic unit cell and are parallel to the shortest c-axis, whilst the main efg axes are parallel to the longest crystallographic axis, b. This orientation is similar to that in Ca2Fe2O5, in spite of the structural differences of strontium and calcium ferrite Brownmillerites at low temperatures.
Tricia L. Meyer - One of the best experts on this subject based on the ideXlab platform.
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symmetry driven atomic rearrangement at a Brownmillerite perovskite interface
Advanced electronic materials, 2016Co-Authors: Tricia L. Meyer, Hyoungjeen Jeen, Xiang Gao, Jonathan R. Petrie, Matthew F. Chisholm, Ho Nyung LeeAbstract:To those investigating new interfacial phenomena, symmetry mismatch is of immense interest. The interfacial and bulk microstructure of the Brownmillerite–perovskite interface is probed using detailed transmission electron microscopy. Unique asymmetric displacements of the tetrahedra at the interface are observed, signifying a compensation mechanism for lattice and symmetry mismatch at the interface.
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Symmetry‐Driven Atomic Rearrangement at a Brownmillerite–Perovskite Interface
Advanced Electronic Materials, 2015Co-Authors: Tricia L. Meyer, Hyoungjeen Jeen, Xiang Gao, Jonathan R. Petrie, Matthew F. Chisholm, Ho Nyung LeeAbstract:To those investigating new interfacial phenomena, symmetry mismatch is of immense interest. The interfacial and bulk microstructure of the Brownmillerite–perovskite interface is probed using detailed transmission electron microscopy. Unique asymmetric displacements of the tetrahedra at the interface are observed, signifying a compensation mechanism for lattice and symmetry mismatch at the interface.
Jing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Symmetry mismatch-driven perpendicular magnetic anisotropy for perovskite/Brownmillerite heterostructures
Nature communications, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Grouping different transition metal oxides together by interface engineering is an important route toward emergent phenomenon. While most of the previous works focused on the interface effects in perovskite/perovskite heterostructures, here we reported on a symmetry mismatch-driven spin reorientation toward perpendicular magnetic anisotropy in perovskite/Brownmillerite heterostructures, which is scarcely seen in tensile perovskite/perovskite heterostructures. We show that alternately stacking perovskite La2/3Sr1/3MnO3 and Brownmillerite LaCoO2.5 causes a strong interface reconstruction due to symmetry discontinuity at interface: neighboring MnO6 octahedra and CoO4 tetrahedra at the perovskite/Brownmillerite interface cooperatively relax in a manner that is unavailable for perovskite/perovskite interface, leading to distinct orbital reconstructions and thus the perpendicular magnetic anisotropy. Moreover, the perpendicular magnetic anisotropy is robust, with an anisotropy constant two orders of magnitude greater than the in-plane anisotropy of the perovskite/perovskite interface. The present work demonstrates the great potential of symmetry engineering in designing artificial materials on demand.
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symmetry mismatch driven perpendicular magnetic anisotropy for perovskite Brownmillerite heterostructures
Nature Communications, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Grouping different transition metal oxides together by interface engineering is an important route toward emergent phenomenon. While most of the previous works focused on the interface effects in perovskite/perovskite heterostructures, here we reported on a symmetry mismatch-driven spin reorientation toward perpendicular magnetic anisotropy in perovskite/Brownmillerite heterostructures, which is scarcely seen in tensile perovskite/perovskite heterostructures. We show that alternately stacking perovskite La2/3Sr1/3MnO3 and Brownmillerite LaCoO2.5 causes a strong interface reconstruction due to symmetry discontinuity at interface: neighboring MnO6 octahedra and CoO4 tetrahedra at the perovskite/Brownmillerite interface cooperatively relax in a manner that is unavailable for perovskite/perovskite interface, leading to distinct orbital reconstructions and thus the perpendicular magnetic anisotropy. Moreover, the perpendicular magnetic anisotropy is robust, with an anisotropy constant two orders of magnitude greater than the in-plane anisotropy of the perovskite/perovskite interface. The present work demonstrates the great potential of symmetry engineering in designing artificial materials on demand.
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Symmetry mismatch-driven perpendicular magnetic anisotropy for perovskite/Brownmillerite heterostructures
Nature Publishing Group, 2018Co-Authors: Jing Zhang, Zhicheng Zhong, Xiangxiang Guan, Xi Shen, Jine Zhang, Furong Han, Hui Zhang, Hongrui Zhang, Xi Yan, Qinghua ZhangAbstract:Complex oxide heterostructures exhibit multifunctional behaviour that could be used in a range of device applications. Here, the authors observe that reconstruction at oxide perovskite/Brownmillerite interfaces leads to perpendicular magnetic spin orientation, with potential use in spintronic devices
