The analysis of propagation of acoustic plane waves in different crystals

By means of the offered analytical method the determinant relation for a phase velocities of elastic waves for an arbitrary propagation directions in a piezoelectric crystal are received. The phase velocities of three normal elastic waves for two crystals LiNbO₃ and KNbO₃ are calculated. Results of this calculation for each of waves are presented graphically in the form of the cards allowing easily to define phase velocities in any given direction in crystal. Therefore conclusions on use of the considered crystals for production of delay lines, with the best parameters can be done.