Anomalous temperature dependence of magnetic anisotropy in gradient-composition sputterred thin films.

An abnormal behavior of increasing magnetic anisotropy with temperature in magnetic thin films fabricated by a gradient-composition sputtering technique is observed and consistently confirmed by two independent measurements of static magnetic hysteresis loops and dynamic magnetic permeability spectra. This peculiar behavior is suggested to be due to the physical origin of stress-induced magnetic anisotropy.