Propagation of the Anisimkin Jr.´ plate modes in LiNbO3 and Te single crystals

Anisimkin Jr.´ modes discovered recently in quartz plates are found now in two other piezoelectric crystals, belonging to trigonal symmetry. In 128degY,X+90deg-LiNbO₃ two different QL modes may propagate simultaneously for small plate thickness h/lambda = 0 - 0.06 (h - thickness, lambda - wavelength). Velocity of the 1^st mode v₁ is close to the longitudinal bulk wave velocity v_L. It is varied with h/lambda and piezoelectrically stiffened (maximum K_n ² = 39 % at h/lambda = 0.08). Velocity of the 2^nd mode v₂ is close to the shear-horizontal bulk wave velocity v_QSH, not varied with h/lambda and not stiffened (K_n ² = 0). On the contrary, 210degY,X-Te crystal supports only one QL-mode, but it is unusually wide-ranging and low-dispersive: the mode exists for all h/lambda from 0 to 2.5 with velocity v_n almost permanent and equal to v_L in the whole range. This mode is piezoelectrically stiffened. Its coupling constant approaches 2 % at h/lambda = 0.13. Variety of the Anisimkin Jr.´ modes in different crystals makes them attractive for liquid sensors, where suitable waves have been restricted till now by SH counterparts.