Dispersion of magnetostatic surface waves in ferrite-HTSC structures near the phase transition

We present a detailed study of the dispersion properties of surface magnetostatic waves in layered structures of ferrite and high temperature superconductor (HTSC) layers. We solve the propagation problem for the surface magnetostatic waves under a quasistatic approximation, and obtain the dispersion relation. We present an analysis of this dispersion near the phase transition temperature in the HTSC layer. The calculations show that when the HTSC material transforms to the superconducting state the dispersion properties of the magnetostatic waves changes suddenly: the damping decreases by 4-10 dB and the phase velocity increases by a factor of 2-4. These results support experiments which have been performed, in which surface magnetostatic waves have been studied in a YIG film with gallium impurities and a YBaCuO film on a lithium niobate substrate