Open AccessIsotropic non-local Gilbert damping driven by spin pumping in epitaxial Pd/Fe films on MgO(001) substrates
Author(s) -
Yan Li,
Y Li,
Q Liu,
Zhongkui Xie,
Eric Vetter,
Zhe Yuan,
Wei He,
H L Liu,
Dali Sun,
Ke Xia,
Wei Yu,
Yun-Bing Sun,
Jianjun Zhao,
X Q Zhang,
ZhaoHua Cheng
Publication year - 2019
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/ab4c8d
Subject(s) - condensed matter physics , spin pumping , isotropy , physics , anisotropy , spintronics , ferromagnetism , spin (aerodynamics) , epitaxy , magnetization , relaxation (psychology) , metal , conductance , magnetic damping , spin polarization , materials science , spin hall effect , magnetic field , nanotechnology , layer (electronics) , quantum mechanics , thermodynamics , electron , psychology , social psychology , vibration , metallurgy
Although both theoretical predictions and experimental observations have demonstrated that the Gilbert damping is anisotropic at ferromagnet/semiconductor interface possessing robust interfacial spin–orbit coupling, it is not well understood whether non-local Gilbert damping driven by spin pumping in heavy metal/ferromagnetic metallic bilayers is anisotropic or not. Here, we investigated the angular and frequency dependence of magnetic relaxation in epitaxial Pd/Fe films on MgO(001) substrates. After disentangling parasitic contributions, we unambiguously observe that the non-local Gilbert damping is isotropic in the Fe(001) plane, suggesting that the spin transport across the Pd/Fe interface is independent of the Fe magnetization orientation. First principles calculations reveal that the effective spin mixing conductance of the Pd/Fe interface is nearly invariant for different magnetization directions, in good agreement with the experimental observations. These results offer valuable insight into spin transport in metallic bilayers, and facilitate the development of next-generation spintronic devices.