Parametric Coupling of the Magnetization and Strain in a Ferrimagnet. I. Parametric Excitation of Magnetostatic and Elastic Modes

Abstract

A theoretical treatment is presented of the parametric coupling between the magnetization and elastic strain in a ferrimagnet produced by magnetic pumping. In this paper the parametric coupling between resonant magnetostatic and elastic modes is discussed. The case of a disk vibrating in a longitudinal mode coupled to the uniform precession mode is discussed in detail. The oscillation threshold for this simple geometry is calculated and shows clearly the dependence of the threshold on the properties of the modes and the magnetoelastic coupling coefficients. It has been found that the threshold calculated for the disk geometry agrees to within an order of magnitude with measurements of the threshold for this effect using single‐crystal YIG spheres.