Spin wave relaxation rate measurement under perpendicular pumping

This paper is concerned with the time variation of the RF magnetization of a ferrite biased to resonance and subject to a first-order spin wave instability. Two methods of a fully experimental measurement of the spin wave relaxation rates are derived from the theoretical results. Experiments are given which were performed in a nonresonant device in order to avoid spurious transient signals. The experimental results of the two methods are shown to be in very good agreement. These results, together with the measurement of the critical field, allow experimental determination of the spin wave-uniform mode coupling constant. In addition, some results of a computer analysis of the entire process are presented and compared to experimental results.