The magnetoresistance effect and magnetic properties in amorphous and nanocrystalline Fe(Cu, Nb)-Si-B ribbons have been investigated, it was observed that the anisotropic magnetoresistance (AMR) of nanocrystalline all...The magnetoresistance effect and magnetic properties in amorphous and nanocrystalline Fe(Cu, Nb)-Si-B ribbons have been investigated, it was observed that the anisotropic magnetoresistance (AMR) of nanocrystalline alloy is much smaller than that of amorphous alloy, Indicating that the anisotropy of nanocrystalline alloy becomes smaller after crystallizing, and the smallest AMR is coincident with the excellent soft magnetic characteristics. It is believed that the smaller magnetic crystalline anisotropy is the origin of the excellent soft magnetic characteristics of nanocrystalline alloy.展开更多
A series of CoFe(4 nm)/ Cu(X nm)M(Y nm)/ CoFe(6 nm) samples have been prepared at room temperature. An exponential decay of the GMR( Giant Magnetoresistance) with Y was observed for fixed X=2nm. The characteristic dec...A series of CoFe(4 nm)/ Cu(X nm)M(Y nm)/ CoFe(6 nm) samples have been prepared at room temperature. An exponential decay of the GMR( Giant Magnetoresistance) with Y was observed for fixed X=2nm. The characteristic decay parameter of Al is obtained to be about 0.26nm, which is rather close to 1 monolayer for Al. A coexistant state of GMR and AMR (anisotropic magnetoresistance) was observed when Y=2 nm. As the Cu spacer is replaced by Al layer, only AMR effect dominates. The experimental data further underline the important role played by the nonmagnetic spacers.展开更多
The anisotropic magnetoresistance (MR) of La_(2/3)Ca_(1/3)MnO_3 (LCMO)/YBa_2Cu_4O_8 (YBCO) /LCMO sandwiches on (001) SrTiO_3 were investigated. Single layer LCMO and sandwiches show in-plane anisotropy of MR. MR stron...The anisotropic magnetoresistance (MR) of La_(2/3)Ca_(1/3)MnO_3 (LCMO)/YBa_2Cu_4O_8 (YBCO) /LCMO sandwiches on (001) SrTiO_3 were investigated. Single layer LCMO and sandwiches show in-plane anisotropy of MR. MR strongly depends on the magnetic field direction. A nearly sinusoidal dependence on the angle between the applied magnetic field and the film plane or transport current was observed. A positive MR was present with lower fields applied not only out-of-plane but also in-plane.展开更多
The uniaxial magnetic anisotropy of obliquely deposited Fe（001）/Pd film on MgO（001） substrate is investigated as a function of deposition angle and film thickness. The values of incidence angle of Fe flux relative...The uniaxial magnetic anisotropy of obliquely deposited Fe（001）/Pd film on MgO（001） substrate is investigated as a function of deposition angle and film thickness. The values of incidence angle of Fe flux relative to surface normal of the substrate are 0°, 45°, 55°, and 70°, respectively. In-situ low energy electron diffraction is employed to investigate the surface structures of the samples. The Fe film thicknesses are determined to be 50 ML, 45 ML, 32 ML, and 24 ML（1 ML = 0.14 nm） by performing x-ray reflectivity on the grown samples, respectively. The normalized remanent magnetic saturation ratio and coercivity are obtained by the longitudinal surface magneto-optical Kerr effect. Here, the magnetic anisotropy constants are quantitatively determined by fitting the anisotropic magnetoresistance curves under different fields.These measurements show four-fold cubic anisotropy in a large Fe film thickness（50 ML） sample, but highly in-plane uniaxial magnetic anisotropies in thin films（24 ML and 32 ML） samples. In the obliquely deposited Fe films, the coercive fields and the uniaxial magnetic anisotropies（UMAs） increase as the deposition angle becomes more and more tilted. In addition, the UMA decreases with the increase of the Fe film thickness. Our work provides the possibility of manipulating uniaxial magnetic anisotropy, and paves the way to inducing UMA by oblique deposition with smaller film thickness.展开更多
The planar Hall effect(PHE),which originates from anisotropic magnetoresistance,presents a qualitative and simple approach to characterize electronic structures of quantum materials by applying an in-plane rotating ma...The planar Hall effect(PHE),which originates from anisotropic magnetoresistance,presents a qualitative and simple approach to characterize electronic structures of quantum materials by applying an in-plane rotating magnetic field to induce identical oscillations in both longitudinal and transverse resistances.In this review,we focus on the recent research on the PHE in various quantum materials,including ferromagnetic materials,topological insulators,Weyl semimetals,and orbital anisotropic matters.Firstly,we briefly introduce the family of Hall effect and give a basic deduction of PHE formula with the second-order resistance tensor,showing the mechanism of the characteristicπ-period oscillation in trigonometric function form with aπ/4 phase delay between the longitudinal and transverse resistances.Then,we will introduce the four main mechanisms to realize PHE in quantum materials.After that,the origin of the anomalous planar Hall effect(APHE)results,of which the curve shapes deviate from that of PHE,will be reviewed and discussed.Finally,the challenges and prospects for this field of study are discussed.展开更多
基金Natural Science Foundation of Liaoning Province!(No. 972812).
文摘The magnetoresistance effect and magnetic properties in amorphous and nanocrystalline Fe(Cu, Nb)-Si-B ribbons have been investigated, it was observed that the anisotropic magnetoresistance (AMR) of nanocrystalline alloy is much smaller than that of amorphous alloy, Indicating that the anisotropy of nanocrystalline alloy becomes smaller after crystallizing, and the smallest AMR is coincident with the excellent soft magnetic characteristics. It is believed that the smaller magnetic crystalline anisotropy is the origin of the excellent soft magnetic characteristics of nanocrystalline alloy.
文摘A series of CoFe(4 nm)/ Cu(X nm)M(Y nm)/ CoFe(6 nm) samples have been prepared at room temperature. An exponential decay of the GMR( Giant Magnetoresistance) with Y was observed for fixed X=2nm. The characteristic decay parameter of Al is obtained to be about 0.26nm, which is rather close to 1 monolayer for Al. A coexistant state of GMR and AMR (anisotropic magnetoresistance) was observed when Y=2 nm. As the Cu spacer is replaced by Al layer, only AMR effect dominates. The experimental data further underline the important role played by the nonmagnetic spacers.
文摘The anisotropic magnetoresistance (MR) of La_(2/3)Ca_(1/3)MnO_3 (LCMO)/YBa_2Cu_4O_8 (YBCO) /LCMO sandwiches on (001) SrTiO_3 were investigated. Single layer LCMO and sandwiches show in-plane anisotropy of MR. MR strongly depends on the magnetic field direction. A nearly sinusoidal dependence on the angle between the applied magnetic field and the film plane or transport current was observed. A positive MR was present with lower fields applied not only out-of-plane but also in-plane.
基金Project supported by the National Basic Research Program of China(Grant Nos.2015CB921403 and 2016YFA0300701)the National Natural Science Foundation of China(Grant Nos.51427801,11374350,and 51671212)the Chinese Government Scholarship(Grant No.2015GXYG37)
文摘The uniaxial magnetic anisotropy of obliquely deposited Fe（001）/Pd film on MgO（001） substrate is investigated as a function of deposition angle and film thickness. The values of incidence angle of Fe flux relative to surface normal of the substrate are 0°, 45°, 55°, and 70°, respectively. In-situ low energy electron diffraction is employed to investigate the surface structures of the samples. The Fe film thicknesses are determined to be 50 ML, 45 ML, 32 ML, and 24 ML（1 ML = 0.14 nm） by performing x-ray reflectivity on the grown samples, respectively. The normalized remanent magnetic saturation ratio and coercivity are obtained by the longitudinal surface magneto-optical Kerr effect. Here, the magnetic anisotropy constants are quantitatively determined by fitting the anisotropic magnetoresistance curves under different fields.These measurements show four-fold cubic anisotropy in a large Fe film thickness（50 ML） sample, but highly in-plane uniaxial magnetic anisotropies in thin films（24 ML and 32 ML） samples. In the obliquely deposited Fe films, the coercive fields and the uniaxial magnetic anisotropies（UMAs） increase as the deposition angle becomes more and more tilted. In addition, the UMA decreases with the increase of the Fe film thickness. Our work provides the possibility of manipulating uniaxial magnetic anisotropy, and paves the way to inducing UMA by oblique deposition with smaller film thickness.
基金Project supported by the National Natural Science Foundation of China(Grant No.11904015)the Fundamental Research Funds for the Central Universities(Grant No.YWF-22-K-101)the National Key R&D Program of China(Grant No.2018YFE0202700)。
文摘The planar Hall effect(PHE),which originates from anisotropic magnetoresistance,presents a qualitative and simple approach to characterize electronic structures of quantum materials by applying an in-plane rotating magnetic field to induce identical oscillations in both longitudinal and transverse resistances.In this review,we focus on the recent research on the PHE in various quantum materials,including ferromagnetic materials,topological insulators,Weyl semimetals,and orbital anisotropic matters.Firstly,we briefly introduce the family of Hall effect and give a basic deduction of PHE formula with the second-order resistance tensor,showing the mechanism of the characteristicπ-period oscillation in trigonometric function form with aπ/4 phase delay between the longitudinal and transverse resistances.Then,we will introduce the four main mechanisms to realize PHE in quantum materials.After that,the origin of the anomalous planar Hall effect(APHE)results,of which the curve shapes deviate from that of PHE,will be reviewed and discussed.Finally,the challenges and prospects for this field of study are discussed.
