Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as ...Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as magnetoelectric(ME)coupling effect at room temperature(RT)in this system have not been demonstrated yet.In this study,epitaxial SmFeO3 films were successfully prepared onto tensile-strain Nb-SrTiO3(Nb-STO)substrates by a pulsed laser deposition(PLD)method.Measurement results show that the films exhibit obvious ferromagnetic and ferroelectric orders at RT.Meanwhile,the magnetic anisotropy gradually changes from out-of-plane(OP)to in-plane(IP)direction with increasing film thickness,which is attributed to the variations of O 2p-Fe 3d hybridization intensity and Fe 3d-orbit occupancy caused by the strain-relaxed effect.Moreover,electrically driven reversible magnetic switching further proves that the SmFeO3 films exhibit the RT ME coupling effect,suggesting promising applications in new-generation electric-write magnetic-read data storage devices.展开更多
Rare-earth nickelates possess intrinsic charge order,orbital order,and electron-lattice coupling,which make them very interesting for applications in oxide-based electronic devices.In this study,we grew NdNiO_(3-δ)(N...Rare-earth nickelates possess intrinsic charge order,orbital order,and electron-lattice coupling,which make them very interesting for applications in oxide-based electronic devices.In this study,we grew NdNiO_(3-δ)(NNO) films with oxygen pressures changing from 27 to 10^(-5) Pa.With decreasing oxygen pressure,the antiferromagnetic state of the NNO film becomes a ferromagnetic state,and the resistance increases significantly.According to combined X-ray absorption spectro scopy and X-ray linear dichroism measurements,the ratio of Ni^(2+)-ions increases with decreasing oxygen-pressure,and the preferred orbital occupation changes from x^(2)-y^(2) to 3 z^(2)-r^(2).In addition,using the ionic-liquid gating method to control the migration of oxygen vacancies,both the magnetic properties and resistance of NNO films can be modulated reversibly.The oxygen vacancy induces a valence in the Ni ions and the orbital occupation changes,which alters the magnetic properties and the electronic transport in these NNO films.This study describes a novel tunable method for electronic devices that use NdNiO_(3-δ) films,and opens new doors for future improvements and functionalities.展开更多
In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single...In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single A-type antiferromagnetic LaMnO3 films no matter whether the tensile or compressive strain was supplied by the substrates. Due to the lattice mismatch between the film and different substrates, the intense strain can induce MnO6 octahedral rotation in the bottom region of the film neighboring the substrate, which leads to the distortion of MnO6 octahedron and the net magnetic behavior. However, the upper part maintains the original A-type antiferromagnetic order due to strain relaxation. The exchange bias effect in single films is attributed to the coupling between the bottom canted magnetic part and the upper antiferromagnetic region. The observation of exchange bias in single films on different substrates enables the emergence of a new class of biasing components in spintronics, which are based on strain-engineering.展开更多
Control of magnetic anisotropy in low-dimensional systems is of paramount importance in terms of their fundamental and technological perspectives.La_(0.7)Sr_(0.3)MnO_(3)(LSMO)is a ferromagnetic half-metal with a high ...Control of magnetic anisotropy in low-dimensional systems is of paramount importance in terms of their fundamental and technological perspectives.La_(0.7)Sr_(0.3)MnO_(3)(LSMO)is a ferromagnetic half-metal with a high Curie temperature and many efforts have been made to control its magnetic anisotropy.However,the relationship between the evolution of the magnetic anisotropy orientation and the electronic structure of low-dimensional LSMO still remains poorly understood.Here,the high-quality superlattices comprised of LSMO and SrMnO_(3)(SMO)layers are synthesized with a compatible structure at the atomic scale.Their magnetic anisotropy is gradually varied from planar to perpendicular by increasing the SMO thickness,and the special fourfold magnetic anisotropy is also observed at the intermediate superlattice thickness.The evolution of the magnetic anisotropy in these systems is confirmed by the electronic transport and magnetic measurements.Moreover,X-ray linear dichroism measurements and first-principles calculations reveal the interfacial orbital reconstruction with the in-plane to out-ofplane magnetic reorientation transition.Therefore,a new microscopic method for magnetic anisotropy manipulation is developed in the present study,enabling discovery of novel phenomena as well as control of the magnetic properties.展开更多
基金financially supported by the National Natural Science Foundation of China (12174237, 51901118, 51871137, and 52171183)the 1331 Engineering of Shanxi Province, the Research Project Supported by Shanxi Scholarship Council of China (2021-093)+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2020L0237)the Project funded by China Postdoctoral Science Foundation (2023M730422)。
基金This work was supported by the National Natural Science Foundation of China(51871137,51901118,51571136 and 61904099).The authors acknowledge Shanghai Synchrotron Radiation Facility at the Beamline BL08U1A and the National Synchrotron Radiation Laboratory at the Beamline BL12-a for the XAS measurements.
文摘Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as magnetoelectric(ME)coupling effect at room temperature(RT)in this system have not been demonstrated yet.In this study,epitaxial SmFeO3 films were successfully prepared onto tensile-strain Nb-SrTiO3(Nb-STO)substrates by a pulsed laser deposition(PLD)method.Measurement results show that the films exhibit obvious ferromagnetic and ferroelectric orders at RT.Meanwhile,the magnetic anisotropy gradually changes from out-of-plane(OP)to in-plane(IP)direction with increasing film thickness,which is attributed to the variations of O 2p-Fe 3d hybridization intensity and Fe 3d-orbit occupancy caused by the strain-relaxed effect.Moreover,electrically driven reversible magnetic switching further proves that the SmFeO3 films exhibit the RT ME coupling effect,suggesting promising applications in new-generation electric-write magnetic-read data storage devices.
基金Project supported by the National Natural Science Foundation of China(51871137,51901118,61434002)the Graduate Student Innovation Project in Shanxi Province(010903010050)。
文摘Rare-earth nickelates possess intrinsic charge order,orbital order,and electron-lattice coupling,which make them very interesting for applications in oxide-based electronic devices.In this study,we grew NdNiO_(3-δ)(NNO) films with oxygen pressures changing from 27 to 10^(-5) Pa.With decreasing oxygen pressure,the antiferromagnetic state of the NNO film becomes a ferromagnetic state,and the resistance increases significantly.According to combined X-ray absorption spectro scopy and X-ray linear dichroism measurements,the ratio of Ni^(2+)-ions increases with decreasing oxygen-pressure,and the preferred orbital occupation changes from x^(2)-y^(2) to 3 z^(2)-r^(2).In addition,using the ionic-liquid gating method to control the migration of oxygen vacancies,both the magnetic properties and resistance of NNO films can be modulated reversibly.The oxygen vacancy induces a valence in the Ni ions and the orbital occupation changes,which alters the magnetic properties and the electronic transport in these NNO films.This study describes a novel tunable method for electronic devices that use NdNiO_(3-δ) films,and opens new doors for future improvements and functionalities.
基金financially supported by the National Key R&D Program of China (2017YFB0405703)the National Natural Science Foundation of China (51871137, 61434002 and 51571136)the Special Funds of Sanjin Scholars Program
文摘In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single A-type antiferromagnetic LaMnO3 films no matter whether the tensile or compressive strain was supplied by the substrates. Due to the lattice mismatch between the film and different substrates, the intense strain can induce MnO6 octahedral rotation in the bottom region of the film neighboring the substrate, which leads to the distortion of MnO6 octahedron and the net magnetic behavior. However, the upper part maintains the original A-type antiferromagnetic order due to strain relaxation. The exchange bias effect in single films is attributed to the coupling between the bottom canted magnetic part and the upper antiferromagnetic region. The observation of exchange bias in single films on different substrates enables the emergence of a new class of biasing components in spintronics, which are based on strain-engineering.
基金financially supported by the National Natural Science Foundation of China(51901118,51871137,12174237,and 52171183)the 1331 Engineering of Shanxi Province+1 种基金the Research Project Supported by Shanxi Scholarship Council of China(2021-093)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2020L0237)。
文摘Control of magnetic anisotropy in low-dimensional systems is of paramount importance in terms of their fundamental and technological perspectives.La_(0.7)Sr_(0.3)MnO_(3)(LSMO)is a ferromagnetic half-metal with a high Curie temperature and many efforts have been made to control its magnetic anisotropy.However,the relationship between the evolution of the magnetic anisotropy orientation and the electronic structure of low-dimensional LSMO still remains poorly understood.Here,the high-quality superlattices comprised of LSMO and SrMnO_(3)(SMO)layers are synthesized with a compatible structure at the atomic scale.Their magnetic anisotropy is gradually varied from planar to perpendicular by increasing the SMO thickness,and the special fourfold magnetic anisotropy is also observed at the intermediate superlattice thickness.The evolution of the magnetic anisotropy in these systems is confirmed by the electronic transport and magnetic measurements.Moreover,X-ray linear dichroism measurements and first-principles calculations reveal the interfacial orbital reconstruction with the in-plane to out-ofplane magnetic reorientation transition.Therefore,a new microscopic method for magnetic anisotropy manipulation is developed in the present study,enabling discovery of novel phenomena as well as control of the magnetic properties.
