Activation volumes in superparamagnetic Fe films determined using Brillouin Light Scattering

摘要

Ultra-thin films of Fe grown in ultra-high-vacuum on GaAs (100) were studied using Brillouin Light Scattering. The films are not continuous but instead a collection of weakly interacting particles and are paramagnetic at room temperature. Spinwave frequency measurements can be used to determine anisotropies above the blocking temperature [1]. We show that temperature dependence can be used to provide a unique measure of particle volume.