Method for searching for pure modes of elastic waves in crystals from 3D phase velocity surfaces

The article suggests a new method for pure modes of elastic waves search in crystals. The method is based on analyzing 3D-surfaces of phase velocities and differs from the known analogous methods by consideration of piezoeffect. The piezoelectric corrections essentially influence the research result. A special computer program has been built to construct these surfaces and their sections from the base planes of a crystal. The program also indicates the directions of pure longitudinal and pure transverse elastic waves propagation on these surfaces.