Nonreciprocity of saw velocity on a magnetized ferrite substrate

Abstract

AbstractSurface acoustic waves (SAW) propagating on piezoelectric materials are now utilized in practical devices such as filters and signal processing. However, only a few papers were reported on SAW propagation on magnetic materials. In this paper, the propagation characteristics of magnetoelastic Rayleigh waves on the YIG substrate are treated experimentally for the bias configuration where dc magnetic bias field is tangential to the substrate surface and oblique to the direction of propagation. The saturation magnetization of the YIG ferrite used for the experiment is 250 and the Rayleigh waves were excited and received by using ZnO thin‐film transducers. In this configuration, the nonreciprocity of surface wave was observed. Its velocity to the forward direction was found to be different from that in the reverse direction. The maximum amount of nonreciprocity obtained experimentally in this paper was approximately 150 ppm. This value is too small for the application, but the unidirectional transducer, the isolator and the device similar to the circulator may be constructed by using the nonreciprocal characteristics of surface wave velocities.