HIGH POWER MICROWAVE FERRITES AND DEVICES.

摘要

The theory of spin-wave generation in nonuniform dc magnetic fields has been further pursued. The coupling length which largely determines the conversion efficiency was calculated by means of the WKB approximation,which is valid when the dc magnetic field varies sufficiently slowly with position. The results should be applicable under typical experimental conditions and indicate that the coupling length is inversely proportional to the square root of the field gradient at the turning point. The effect of magnetoelastic interaction on spin-wave propagation in nonuniform dc fields was considered. Several garnet materials containing rapidly relaxing rare earth ions were found to have high subsidiary absorption thresholds and moderately narrow linewidths. A correlation between dielectric loss tangent and subsidiary absorption threshold appears to account for the high thresholds previously reported on some low magnetization samples. (Author)