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
Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-dep...Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-depth understanding of their magnetic properties remain challenging.Here,low-dimensional assemblies of iron oxide nanocubes with a disordered arrangement are fabricated at the diethylene-glycol/air interface in the presence of assembly fields(0/1/3/5/30/50 mT).Ring-shaped assemblies gradually transform as the assembly field increases from 0 to 50 mT,first to a porous network consisting of elongated assemblies and then to an aligned array of filaments,in which the aligned filaments are formed when the assembly field is≥3 mT and duration t>14 min.Spin-glass characteristics and static(dynamic)anisotropy factors~2(3)are achieved by tuning the strength of the assembly field.In the presence of a relatively weak assembly field,the interplay between dipolar interactions and disorder with respect to magnetic easy axis alignment leads to spin-glass characteristics.The alignment of the magnetic easy axes and the strength of the dipolar interactions increase with increasing assembly field,resulting in the disappearance of spin-glass characteristics and enhancement of the magnetic anisotropy.This study presents a strategy for obtaining magnetic assemblies with spin-glass behavior and controllable anisotropy while shedding light on the magnetic interactions of low-dimensional assemblies.展开更多
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financially supported by Shenzhen Science and Technology Project(CYJ20180507182246321 and JCYJ20200109105825504)Swedish Research Council VR(2016-06959)financial support from the Doctoral Joint-Training Program of China Scholarship Council.
文摘Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-depth understanding of their magnetic properties remain challenging.Here,low-dimensional assemblies of iron oxide nanocubes with a disordered arrangement are fabricated at the diethylene-glycol/air interface in the presence of assembly fields(0/1/3/5/30/50 mT).Ring-shaped assemblies gradually transform as the assembly field increases from 0 to 50 mT,first to a porous network consisting of elongated assemblies and then to an aligned array of filaments,in which the aligned filaments are formed when the assembly field is≥3 mT and duration t>14 min.Spin-glass characteristics and static(dynamic)anisotropy factors~2(3)are achieved by tuning the strength of the assembly field.In the presence of a relatively weak assembly field,the interplay between dipolar interactions and disorder with respect to magnetic easy axis alignment leads to spin-glass characteristics.The alignment of the magnetic easy axes and the strength of the dipolar interactions increase with increasing assembly field,resulting in the disappearance of spin-glass characteristics and enhancement of the magnetic anisotropy.This study presents a strategy for obtaining magnetic assemblies with spin-glass behavior and controllable anisotropy while shedding light on the magnetic interactions of low-dimensional assemblies.
