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/cm2,1 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=0.42×1015 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.

Wenqiang Wang;Gengkuan Zhu;Kaiyuan Zhou;Xiang Zhan;Zui Tao;Qingwei Fu;Like Liang;Zishuang Li;Lina Chen;Chunjie Yan;Haotian Li;Tiejun Zhou;Ronghua Liu

National Laboratory of Solid State Microstructures,School of Physics and Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China;New Energy Technology Engineering Laboratory of Jiangsu Provence and School of Science,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;Centre for Integrated Spintronic Devices,School of Electronics and Information,Hangzhou Dianzi University,Hangzhou 310018,China

中国物理B（英文版）

[1]Wenqiang Wang;Gengkuan Zhu;Kaiyuan Zhou;Xiang Zhan;Zui Tao;Qingwei Fu;Like Liang;Zishuang Li;Lina Chen;Chunjie Yan;Haotian Li;Tiejun Zhou;Ronghua Liu-.Enhancement of spin-orbit torque efficiency by tailoring interfacial spin-orbit coupling in Pt-based magnetic multilayers)[J].中国物理B（英文版）,2022(09):160-165

SOTs,trilayers

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