Exchange coupling across the interface between a ferromagnetic(FM)layer and an antiferromagnetic(AFM)or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy,which has ...Exchange coupling across the interface between a ferromagnetic(FM)layer and an antiferromagnetic(AFM)or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy,which has been extensively studied due to the important application in magnetic materials and devices.In this work,we observed a fourfold magnetic anisotropy in amorphous Co Fe B layer when exchange coupling to an adjacent Fe Rh layer which is epitaxially grown on an SrTiO_(3)(001)substrate.As the temperature rises from 300 K to 400 K,Fe Rh film undergoes a phase transition from AFM to FM phase,the induced fourfold magnetic anisotropy in the Co Fe B layer switches the orientation from the Fe Rh<110>to Fe Rh<100>directions and the strength is obviously reduced.In addition,the effective magnetic damping as well as the two-magnon scattering of the Co Fe B/Fe Rh bilayer also remarkably increase with the occurrence of magnetic phase transition of Fe Rh.No exchange bias is observed in the bilayer even when Fe Rh is in the nominal AFM state,which is probably because the residual FM Fe Rh moments located at the interface can well separate the exchange coupling between the below pinned Fe Rh moments and the Co Fe B moments.展开更多
Multistate magnetic memory effect in heterostructures composed of FeRh thin films with antiferromagnetic(AFM)-ferromagnetic(FM)phase transition and(001)-oriented PMN-PT substrates has been investigated.Utilizing a uni...Multistate magnetic memory effect in heterostructures composed of FeRh thin films with antiferromagnetic(AFM)-ferromagnetic(FM)phase transition and(001)-oriented PMN-PT substrates has been investigated.Utilizing a unipolar electric field,the nonvolatile change in magnetization was nearly doubled compared with that obtained utilizing a conventional bipolar bias.Four stable nonvolatile magnetic states were obtained over a broad temperature span,from 320 to 390K,by adjusting the amplitude of the unipolar electric pulses,demonstrating the possibility of realizing a multistate nonvolatile magnetic memory in the FeRh/PMN-PT heterostructures.This work provides a new strategy for enhancing the magnetic response by utilizing unipolar electric fields and promotes the utilization of AFM-FM phase transition materials in multifunctional information storage and novel spintronic devices.展开更多
In this paper, the structure and magnetic properties of FeRh alloy thin films with a small amount of Pt doping fabricated onto a glass substrate by sputtering are investigated systematically. XRD results show that the...In this paper, the structure and magnetic properties of FeRh alloy thin films with a small amount of Pt doping fabricated onto a glass substrate by sputtering are investigated systematically. XRD results show that the diffraction pattern of as-deposited film exhibits only nonmagnetic y phase. After annealing, the disordered γphase transforms to an ordered α＇ phase. The temperature dependence of saturation magnetization of different annealing times and Pt contents are characterized. The phase transition temperature increases as the Pt component is increased, but the saturation magnetization reduces as the Pt component is in- creased. These results may be caused by the growth of the disordered γ phase.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874150,51871233,and 12174103)the Natural Science Foundation of Shanghai(Grant Nos.21ZR1420500 and 21JC1402300)。
文摘Exchange coupling across the interface between a ferromagnetic(FM)layer and an antiferromagnetic(AFM)or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy,which has been extensively studied due to the important application in magnetic materials and devices.In this work,we observed a fourfold magnetic anisotropy in amorphous Co Fe B layer when exchange coupling to an adjacent Fe Rh layer which is epitaxially grown on an SrTiO_(3)(001)substrate.As the temperature rises from 300 K to 400 K,Fe Rh film undergoes a phase transition from AFM to FM phase,the induced fourfold magnetic anisotropy in the Co Fe B layer switches the orientation from the Fe Rh<110>to Fe Rh<100>directions and the strength is obviously reduced.In addition,the effective magnetic damping as well as the two-magnon scattering of the Co Fe B/Fe Rh bilayer also remarkably increase with the occurrence of magnetic phase transition of Fe Rh.No exchange bias is observed in the bilayer even when Fe Rh is in the nominal AFM state,which is probably because the residual FM Fe Rh moments located at the interface can well separate the exchange coupling between the below pinned Fe Rh moments and the Co Fe B moments.
基金supported by the National Key Research and Development Program of China(Grant Nos.2020YFA0711502,2019YFA0704900,2018YFA0305704,and 2017YFB0702704)National Natural Science Foundation of China(Grant Nos.52088101,U1832219,51771223,51971240,and 51671022)+3 种基金China Postdoctoral Science Foundation(Grant No.2021M690346)Fundamental Research Funds for the Central Universities and the Youth Teacher International Exchange&Growth Program(Grant Nos.FRF-GF-20-08B,and QNXM20210014)State Key Lab of Advanced Metals and Materials(Grant No.2019-Z11)Key Program and Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB33030200)。
文摘Multistate magnetic memory effect in heterostructures composed of FeRh thin films with antiferromagnetic(AFM)-ferromagnetic(FM)phase transition and(001)-oriented PMN-PT substrates has been investigated.Utilizing a unipolar electric field,the nonvolatile change in magnetization was nearly doubled compared with that obtained utilizing a conventional bipolar bias.Four stable nonvolatile magnetic states were obtained over a broad temperature span,from 320 to 390K,by adjusting the amplitude of the unipolar electric pulses,demonstrating the possibility of realizing a multistate nonvolatile magnetic memory in the FeRh/PMN-PT heterostructures.This work provides a new strategy for enhancing the magnetic response by utilizing unipolar electric fields and promotes the utilization of AFM-FM phase transition materials in multifunctional information storage and novel spintronic devices.
基金supported by the National Natural Science Foundation of China (Grant No. 50901052)the Program for Young Excellent Talents in Tongji University (Grant No. 2009KJ003)the "Chen Guang" Project(Grant No. 10CG21) of the Shanghai Municipal Education Commission and Shanghai Education Development Foundation
文摘In this paper, the structure and magnetic properties of FeRh alloy thin films with a small amount of Pt doping fabricated onto a glass substrate by sputtering are investigated systematically. XRD results show that the diffraction pattern of as-deposited film exhibits only nonmagnetic y phase. After annealing, the disordered γphase transforms to an ordered α＇ phase. The temperature dependence of saturation magnetization of different annealing times and Pt contents are characterized. The phase transition temperature increases as the Pt component is increased, but the saturation magnetization reduces as the Pt component is in- creased. These results may be caused by the growth of the disordered γ phase.
