Effect of Ga composition on the static and dynamic magnetic properties of Fe100-Ga films (18.5 ≤ x ≤ 33.4)

Abstract This paper describes the effect of Ga composition ( x ) on the static and dynamic magnetic properties of 50-nm-thick Fe 100- x Ga x films (18.5 ≤  x  ≤ 33.4). The in-plane damping constant ( α // ), the perpendicular (out-of-plane) damping constant ( α ⊥ ), the saturation magnetostriction (λ s ) and the maximum piezomagnetic coefficient ((d λ /d H ) max ) of these films are dependent on x , whereas the tendencies of α // and α ⊥ for x are quite opposite to those of λ s and (d λ /d H ) max for x . For every x , the value of α // is much larger than that of α ⊥ , suggesting that both the intrinsic damping and the extrinsic damping coexists in the in-plane dynamics of each Fe 100- x Ga x film because of magnetic inhomogeneities such as two magnon scattering, anisotropy dispersion and so on. These results also demonstrate that only the intrinsic damping contributes to the out-of-plane dynamics of each Fe 100- x Ga x film.