Guided Wave Propagation in a Gold Electrode Film on a Pb(Mg_1/3Nb_2/3)O₃–33%PbTiO₃ Ferroelectric Single Crystal Substrate

Dispersion relations of Love mode acoustic guided waves propagation in Pb(Mg_1/3Nb_2/3)O₃–33%PbTiO₃ (PMN-0.33 PT) single crystal with a gold electrode film are calculated. There is no cross coupling among Love wave modes, which is conducive to eliminating the cross interference between modes. The general formula is derived to precisely measure the thickness of the electrode. More acoustic energy would be concentrated inside the electrode with the increase of film thickness for a given frequency. Compared with the PZT-5 ceramic, 001_c poled PMN-33%PT single crystal has a slower attenuation of the amplitude of the acoustic guided wave. Therefore, single crystal is extremely suitable for making low loss acoustic wave devices with a high operating frequency.