Thickness and temperature dependence of magnetic anisotropies of Ni77Mn23 films


Aktas B., OZDEMIR M., YILGIN R., Oner Y. , SATO T., ANDO T.

PHYSICA B, cilt.305, ss.298-314, 2001 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

Magnetic properties of polycrystalline reentrant Ni77Mn23 films of various thickness ( 50, 100, 300, 600, 1000 and 3700 Angstrom) were studied by both spin wave resonance (SWR) and DC magnetization techniques as a function of temperature. All films show spin-glass properties at the temperature range below freezing temperature T-f (congruent to 120 K). For temperatures well-above T-f, most of the films exhibit multi-peak ESR spectra at both X-and Q-band when the external field is oriented within a small interval of a solid angle around the film normal. The number of peaks increases with film thickness, indicating long spin wave excitation across the film thickness. The angular dependent SWR spectra were successfully analyzed by usual classical SWR theory. Hence, the SWR parameters were deduced for magnetic energy density including Zeeman, effective magneto-crystalline and unidirectional bulk and surface anisotropies, oblique anisotropy, spin-wave energy (exchange energy) and magnetic damping terms.