Rapid and nondestructive measurement of the anisotropy field in bubble garnet films

A microwave resonant cavity has been developed for nondestructive ferromagnetic resonance (FMR) measurements of bubble garnet films. The cavity allows the examination of intact wafers up to 3 inches in diameter. The cavity design and the results of FMR studies using this cavity are reported. The typical measurement time of the effective anisotropy field Hk- 4πMsin bubble films with the precision of ±1% is less than 30 s. The results are compared with an improved magneto-optic method which requires the measurement time of 5 min with the precision of ±4%.