TY - JOUR
T1 - Evaluation of damping constants for Co/Pt multilayers and CoPt alloy films
AU - Kusanagi, Yusaku
AU - Kikiichi, Satoshi Okamoto Nobuaki
AU - Kitakami, Osamu
AU - Kato, Takeshi
AU - Ivvata, Satoshi
N1 - Publisher Copyright:
© 2016 The Institute of Electrical Engineers of Japan.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - In this study, the damping constants of Co/Pt multilayers and hexagonal-closed-packed (hcp) CoPt alloy films are investigated by using a vector network analizer ferromagnetic resonance spectroscopy (VNA-FMR) and time resolved magneto-optical Ken- effect (TR-MOKE). For Co/Pt multilayer films, very clear linear relationship between FMR frequency and absorption peak width is found. From this relationship, the damping constants of Co/Pt multilayers are evaluated to be about 0.02 - 0.07 with very small extrinsic contributions. On the other hand, for CoPt alloy films, the absorption peak width becomes wider and exhibits very little FMR frequency dependence. The damping constants of CoPt alloy films evaluated by TR-MOKE. however, are as small as about 0.03 - 0.06. being almost the same with that Co/Pt multilayers. These discrepancies found in CoPt alloy films can be explained by assuming the large distribution of magnetic anisotropy. Thus the damping constant of CoPt alloy films are some what larger than that of Co/Pt multilayers when these results are compared at same Pt composition.
AB - In this study, the damping constants of Co/Pt multilayers and hexagonal-closed-packed (hcp) CoPt alloy films are investigated by using a vector network analizer ferromagnetic resonance spectroscopy (VNA-FMR) and time resolved magneto-optical Ken- effect (TR-MOKE). For Co/Pt multilayer films, very clear linear relationship between FMR frequency and absorption peak width is found. From this relationship, the damping constants of Co/Pt multilayers are evaluated to be about 0.02 - 0.07 with very small extrinsic contributions. On the other hand, for CoPt alloy films, the absorption peak width becomes wider and exhibits very little FMR frequency dependence. The damping constants of CoPt alloy films evaluated by TR-MOKE. however, are as small as about 0.03 - 0.06. being almost the same with that Co/Pt multilayers. These discrepancies found in CoPt alloy films can be explained by assuming the large distribution of magnetic anisotropy. Thus the damping constant of CoPt alloy films are some what larger than that of Co/Pt multilayers when these results are compared at same Pt composition.
KW - Co/Pt multilayer film Co
KW - Damping constant
KW - Ferromagnetic resonance
KW - Perpendicular magnetic film
KW - Pt alloy film
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U2 - 10.1541/ieejfms.136.317
DO - 10.1541/ieejfms.136.317
M3 - Article
AN - SCOPUS:84971336965
VL - 136
SP - 317
EP - 323
JO - IEEJ Transactions on Fundamentals and Materials
JF - IEEJ Transactions on Fundamentals and Materials
SN - 0385-4205
IS - 5
ER -