Experimental Studies of Spinwaves Excited by Parallel Pumping†

Abstract
The excitation of spinwaves by a microwave magnetic field in the parallel-pump configuration is described. A swept magnetic field technique for detecting the absorption of microwave energy is employed. Values for the acoustic Q -factor, the magnetoelastic coupling coefficient and exchange constant are obtained for single-crystal yttrium-iron garnet. Verification of Morgenthaler's theory of spinwave-phonon interaction is provided. Experiments employing superimposed r.f. modulation of the magnetic field are in general agreement with Suhl's theory. Observations of relaxation oscillations have been made which differ from those previously reported.