Spin-wave resonance and magnetic anisotropy in FePt thin films

Ferromagnetic Resonance (FMR) measurements at room temperature and X-band microwave frequency were performed on polycrystalline FePt thin films with face-centered cubic structure. With the external field perpendicular to the film plane, the absorption fields H-n of the odd and even spin-wave resonance modes n detected for the Fe0.44Pt0.56(45 nm)/Si(1 0 0) and Fe0.51Pt0.49(105 nm)/ Pt(55 nm)/MgO(1 0 0) films, were found to obey the well-known H-n x n(2) ratio, giving for these films the exchange stiffness constant values of 3.9 x 10(-8) and 4.4 x 10(-7) erg/cm, respectively. The study of the out-of-plane angular dependence of the absorption field of the uniform FMR mode allowed the measurement of the effective magnetic anisotropy constants of 5.3 x 10(6), 6.4 x 10(6), and 6.7 x 10(6) erg/cm(3), related, respectively, to the [1 1 1], [1 0 0], and [1 1 0] textures present in the films. (c) 2006 Elsevier B.V. All rights reserved.