TY - JOUR
T1 - Effect of Lattice Strain on Soft Magnetic Properties in FeCo/NiFe(Cr) Thin Films with 2.4 T
AU - Shimatsu, T.
AU - Katada, H.
AU - Watanabe, I.
AU - Muraoka, Hiroaki
AU - Nakamura, Y.
N1 - Funding Information:
Manuscript received January 2, 2003. This work was supported in part by MEXT under the IT Program RR2002, the Japan Society for the Promotion of Science Research for the Future Program under JSPS-RFTF 99R14401, and the Semiconductor Research Corporation. The authors are with the Research Institute of Electrical Communication, To-hoku University, Sendai 980-8577, Japan (e-mail: shimatsu@riec.tohoku.ac.jp). Digital Object Identifier 10.1109/TMAG.2003.815451 Fig. 1. Values of H as a function of Ar pressure during film deposition for Ta/NiFe(5 nm)/Fe Co (100 nm)/NiFe(5 nm)/Ta films and Ta/Fe Co (100 nm)/NiFeCr(5 nm)/Ta films.
PY - 2003/9
Y1 - 2003/9
N2 - The soft magnetic property of FeCo films with thin NiFe or NiFeCr seed layers (saturation flux density of 2.4 T) is discussed in relation to lattice strain of the FeCo films. The coercivity along hard axis of magnetization (HcHA) reduces as the Ar pressure during sputtering deposition decreases, and moreover, shows the lowest value at FeCo thickness of 50-100 nm. FeCo films show bcc-(110) preferred grain orientation with the 〈110〉 direction sharply perpendicular to the film plane. X-ray diffraction (XRD) patterns indicate that the absolute magnitude of the lattice strains of (110), (-110), and (001) planes reduce as the Ar pressure decreases. Magnetic anisotropy energy in (110) plane (E) was calculated by including magnetostrictive energy due to the lattice strain. It was successfully shown that the Ar pressure dependence of E is in good agreement with that of H cHcA. Moreover, it is suggested that thickness dependence of HcHA is significantly related to that of magnetostrictive energy. It is likely that less lattice deformation, which is formed by the hetero-epitaxial growth of the FeCo(110) plane on the fcc-(111) plane of the NiFe(Cr) layer, is a key to derive soft magnetic properties in the FeCo/NiFe(Cr) films.
AB - The soft magnetic property of FeCo films with thin NiFe or NiFeCr seed layers (saturation flux density of 2.4 T) is discussed in relation to lattice strain of the FeCo films. The coercivity along hard axis of magnetization (HcHA) reduces as the Ar pressure during sputtering deposition decreases, and moreover, shows the lowest value at FeCo thickness of 50-100 nm. FeCo films show bcc-(110) preferred grain orientation with the 〈110〉 direction sharply perpendicular to the film plane. X-ray diffraction (XRD) patterns indicate that the absolute magnitude of the lattice strains of (110), (-110), and (001) planes reduce as the Ar pressure decreases. Magnetic anisotropy energy in (110) plane (E) was calculated by including magnetostrictive energy due to the lattice strain. It was successfully shown that the Ar pressure dependence of E is in good agreement with that of H cHcA. Moreover, it is suggested that thickness dependence of HcHA is significantly related to that of magnetostrictive energy. It is likely that less lattice deformation, which is formed by the hetero-epitaxial growth of the FeCo(110) plane on the fcc-(111) plane of the NiFe(Cr) layer, is a key to derive soft magnetic properties in the FeCo/NiFe(Cr) films.
KW - FeCo films
KW - High saturation magnetization
KW - Lattice strain
KW - Magnetostrictive energy
KW - Soft magnetic properties
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U2 - 10.1109/TMAG.2003.815451
DO - 10.1109/TMAG.2003.815451
M3 - Article
AN - SCOPUS:0141953901
SN - 0018-9464
VL - 39
SP - 2365
EP - 2367
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 5 II
ER -