TY - JOUR
T1 - Annealing effect and interlayer modulation on magnetic damping of CoFeB/interlayer/Pt thin films
AU - Zhu, Zhendong
AU - Zhao, Bingcheng
AU - Zhu, Weihua
AU - Tang, Minghong
AU - Ren, Yang
AU - Jin, Q. Y.
AU - Zhang, Zongzhi
N1 - Publisher Copyright:
© 2018 Author(s).
PY - 2018/11/26
Y1 - 2018/11/26
N2 - The annealing effect and interlayer (IL) modulation on the magnetic damping properties of CoFeB/IL/Pt (IL = Ta or Ru) multilayers have been systematically studied by the time-resolved magneto-optical Kerr effect. It is found that after inserting a thin IL, the saturated magnetic damping factor αs drops considerably due to the reduced spin pumping effect. By fitting the curves of αs versus IL thickness, spin diffusion lengths of Ta and Ru are determined to be 3.07 and 3.59 nm, respectively. Interestingly, for the CoFeB samples with different capping layers of Pt, Ta/Pt, or Ru/Pt, the αs values exhibit an identical non-monotonic variation tendency as annealing temperature (Ta) increases. It first rises to a maximum at Ta ∼ 100 °C and then decreases, reaching a minimum value (αs = 0.021-0.011) at Ta ∼ 300 °C. After that, αs starts to increase again. Such a complicated variation behavior is attributed to two-magnon scattering contribution, which originates from the change in the CoFeB surface roughness and interfacial atomic intermixing induced by thermal annealing. This study provides a deep understanding and effective control of magnetic damping for practical design of high performance spintronic devices.
AB - The annealing effect and interlayer (IL) modulation on the magnetic damping properties of CoFeB/IL/Pt (IL = Ta or Ru) multilayers have been systematically studied by the time-resolved magneto-optical Kerr effect. It is found that after inserting a thin IL, the saturated magnetic damping factor αs drops considerably due to the reduced spin pumping effect. By fitting the curves of αs versus IL thickness, spin diffusion lengths of Ta and Ru are determined to be 3.07 and 3.59 nm, respectively. Interestingly, for the CoFeB samples with different capping layers of Pt, Ta/Pt, or Ru/Pt, the αs values exhibit an identical non-monotonic variation tendency as annealing temperature (Ta) increases. It first rises to a maximum at Ta ∼ 100 °C and then decreases, reaching a minimum value (αs = 0.021-0.011) at Ta ∼ 300 °C. After that, αs starts to increase again. Such a complicated variation behavior is attributed to two-magnon scattering contribution, which originates from the change in the CoFeB surface roughness and interfacial atomic intermixing induced by thermal annealing. This study provides a deep understanding and effective control of magnetic damping for practical design of high performance spintronic devices.
UR - https://www.scopus.com/pages/publications/85057540398
U2 - 10.1063/1.5050445
DO - 10.1063/1.5050445
M3 - 文章
AN - SCOPUS:85057540398
SN - 0003-6951
VL - 113
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 22
M1 - 222403
ER -