Temperature dependent magnetization of individual, substrate-free YIG bridges measured using cantilever magnetometry

Yttrium iron garnet (Y₃Fe₅O₁₂), or YIG, is an insulating ferrimagnet whose extremely low magnetic loss makes it attractive for many research and technological applications. Many applications require thin films that are deposited on lattice-matched gadolinium-gallium-garnet (GGG). These films often exhibit a saturation magnetization significantly exceeding theoretical values; this may arise from their interactions with the substrate. Using a novel sample preparation technique, micron sized YIG structures have been separated from the GGG substrate. This allows individual, substrate-free micron bridges to be transferred to a silicon nitride cantilever for cantilever magnetometry measurements. The variation of the resonant frequency of the cantilever as a function of applied magnetic field allows the magnetization and magnetic anisotropy to be determined. We report on these quantities as a function of temperature.