APPLICATIONS OF MAGNETOELASTIC EFFECTS TO ACOUSTIC SURFACE WAVE DEVICES.

Magnetoelastic Rayleigh wave delay lines have been fabricated with epitaxial magnetic garnet films. Interdigital transducers deposited on a zinc oxide layer have been used for acoustic wave excitation and detection. An external bias magnetic field has been applied in the garnet film plane in order to control magnetoelastic interactions. A non-reciprocal effect has been observed in a pure Y. I. G. film. Approximately 25 dB difference in forward to backward attenuations has been observed. Important variations in the SAW phase velocity versus magnetic field have been observed in Gd-Ga Y. I. G. ″easy-plane″ films. Such delay lines have been used for implementing tunable oscilltors with clean spectral response.