Direction of displacement in LiNbO3X-cut plate shear transducer

The direction of the particle displacement in the dominant acoustic shear wave mode in the LiNb0
₃
X-cut plate is noted to be at 37.86° from the +Z axis to the -Y axis by using a zero spurious condition in the surface wave propagating along the X-axis on the 127.86° rotated Y-cut plate. The energy ratio of the weak mode to the dorninant mode is estimated to be 0.0066 by using an octahedron model.