We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy...We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy density(Ks=2.7 erg/cm^(2),1 erg=10^(-7) J),which is dominated by interfacial spin-orbit coupling(ISOC)in the Pt/Co interface,total effective spin-mixing conductance(G↑↓eff,tot=0.42×10^(15) Ω^(-1)·m^(-2))and two-magnon scattering(βTMS=0.46 nm2)are first characterized,and the damping-like torque(ξDL=0.103)and field-like torque(ξFL=-0.017)efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer.The significant enhancement of ξDL and ξFL in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface.Additionally,we find a considerable out-of-plane spin polarization SOT,which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface.Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation.Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.展开更多
The binary alloy/ferromagnetic metal heterostructure has drawn extensive attention in the research field of spin–orbittorque(SOT)due to the potential enhancement of SOT efficiency via composition engineering.In this ...The binary alloy/ferromagnetic metal heterostructure has drawn extensive attention in the research field of spin–orbittorque(SOT)due to the potential enhancement of SOT efficiency via composition engineering.In this work,the magneticproperties and SOT efficiency in the Pt100−xNix/Ni78Fe22 bilayers were investigated via the spin-torque ferromagneticresonance(ST-FMR)technique.The effective magnetic anisotropy field and effective damping constant extracted by analyzing the ST-FMR spectra show a weak dependence on the Ni concentration.The effective spin-mixing conductanceof 8.40×10^(14)Ω−1·m−2and the interfacial spin transparency Tin of 0.59 were obtained for the sample of Pt70Ni30/NiFebilayer.More interestingly,the SOT efficiency that is carefully extracted from the angular dependence of ST-FMR spectrashows a nonmonotonic dependence on the Ni concentration,which reaches the maximum at x=18.The enhancement ofthe SOT efficiency by alloying the Ni with Pt shows potential in lowering the critical switching current.Moreover,alloyingrelatively cheaper Ni with Pt may promote to reduce the cost of SOT devices.展开更多
Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel ...Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel junctions(MTJs).The droplet nucleation is accompanied by power enhancement compared with its ferromagnetic resonance modes.The nucleation and stabilization of droplets are ascribed to the double-Co Fe B free-layer structure in the all-perpendicular MTJ,which provides a low Zhang-Li torque and a high pinning field.Our results enable better electrical sensitivity in fundamental studies of droplets and show that the droplets can be utilized in MTJ-based applications and materials science.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774150,12074178,11874135,and 12004171)the Applied Basic Research Programs of the Science and Technology Commission Foundation of Jiangsu Province,China(Grant No.BK20200309)+1 种基金the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology,Key Research and Development Program of Zhejiang Province,China(Grant No.2021C01039)the Scientific Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY220164).
文摘We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy density(Ks=2.7 erg/cm^(2),1 erg=10^(-7) J),which is dominated by interfacial spin-orbit coupling(ISOC)in the Pt/Co interface,total effective spin-mixing conductance(G↑↓eff,tot=0.42×10^(15) Ω^(-1)·m^(-2))and two-magnon scattering(βTMS=0.46 nm2)are first characterized,and the damping-like torque(ξDL=0.103)and field-like torque(ξFL=-0.017)efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer.The significant enhancement of ξDL and ξFL in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface.Additionally,we find a considerable out-of-plane spin polarization SOT,which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface.Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation.Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51901025 and 51625101)the Fundamental Research Funds for the CentralUniversities,China(Grant No.310421101)the Beijing Natural Science Foundation,China(Grant No.Z190007).
文摘The binary alloy/ferromagnetic metal heterostructure has drawn extensive attention in the research field of spin–orbittorque(SOT)due to the potential enhancement of SOT efficiency via composition engineering.In this work,the magneticproperties and SOT efficiency in the Pt100−xNix/Ni78Fe22 bilayers were investigated via the spin-torque ferromagneticresonance(ST-FMR)technique.The effective magnetic anisotropy field and effective damping constant extracted by analyzing the ST-FMR spectra show a weak dependence on the Ni concentration.The effective spin-mixing conductanceof 8.40×10^(14)Ω−1·m−2and the interfacial spin transparency Tin of 0.59 were obtained for the sample of Pt70Ni30/NiFebilayer.More interestingly,the SOT efficiency that is carefully extracted from the angular dependence of ST-FMR spectrashows a nonmonotonic dependence on the Ni concentration,which reaches the maximum at x=18.The enhancement ofthe SOT efficiency by alloying the Ni with Pt shows potential in lowering the critical switching current.Moreover,alloyingrelatively cheaper Ni with Pt may promote to reduce the cost of SOT devices.
基金supported by the Beijing Municipal Science and Technology Project(Grant No.Z201100004220002)the National Natural Science Foundation of China(Grant Nos.61627813,61904009)the China Postdoctoral Science Foundation Funded Project(Grant No.2018M641151)。
文摘Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel junctions(MTJs).The droplet nucleation is accompanied by power enhancement compared with its ferromagnetic resonance modes.The nucleation and stabilization of droplets are ascribed to the double-Co Fe B free-layer structure in the all-perpendicular MTJ,which provides a low Zhang-Li torque and a high pinning field.Our results enable better electrical sensitivity in fundamental studies of droplets and show that the droplets can be utilized in MTJ-based applications and materials science.