Magnetic anisotropy in Fe81Ga19/MgO (100) films sputtered at different powers

A. BUTERA; J. GÓMEZ; J. A. BARNARD; J.L.WESTON

Reñaca, Chile

Workshop; VII Latin American Workshop on Magnetism and Magnetic Materials; 2005

We present a study of the magnetic anisotropy of Fe 81 Ga 19 thin alloyfilms (90 nm thick), sputtered deposited on MgO (100) wafers forsputtering powers in the range 35 W £ P £ 75 W. The films havebeen characterized at room temperature using angular magnetizationremanence and ferromagnetic resonance measurements at 9.7 GHz.For low sputtering powers the films grow epitaxially presenting anin-plane cubic magnetic anisotropy of magnetocrystalline origin,which changes to uniaxial when P is increased. The analysis of theresonance linewidth indicates that the films tend to be moredisordered as the sputtering power increases. However, the filmsputtered at 75 W, in which the induced uniaxial anisotropydominates, has the smallest linewidth. The transition from cubic touniaxial magnetic anisotropy may be due to a poorer epitaxial growthin the films sputtered at higher deposition rates.