A method of determining acoustical physical constants forpiezoelectric materials by line-focus-beam acoustic microscopy

摘要

We developed a new method of determining acoustical physicalnconstants (elastic constant, piezoelectric constant, dielectricnconstant, and density) of piezoelectric materials with high accuracy.nThis method acquires velocities of leaky surface acoustic waves (LSAWs)nexcited on the water-loaded specimen surface, measured bynline-focus-beam (LFB) acoustic microscopy, and bulk velocities ofnlongitudinal and shear waves, measured with planewave transducersnreplacing the LFB device in the same system, together with thendielectric constants and density measured independently, for a smallnnumber of specimens. For LiNbO3 and LiTaO3ncrystals, we demonstrated that we could accurately determine thenconstants by choosing proper propagation directions of LSAWs and bulknwaves for three principal X-, Y-, and Z-cut specimens and one rotatednY-cut specimen [(104) plate for LiNbO3 and (012) plate fornLiTaO3]. The accuracy is nearly the same as that for thenconstants determined only from the bulk wave velocities