Microwave Acoustic Attenuation in CTGS Single Crystals.

This article presents a study of special material properties of the single crystalline material CaTaGaSiO (CTGS = Catangasite). The comparatively highly ordered crystal structure and acceptable piezoelectric strength make it a candidate for microacoustic applications under extreme conditions. Obviously, low-loss dynamic behavior is typical for this crystal which consequently enables high-temperature use.

Anisotropy of the Uniaxial Pressure Influence on Lamb and SH Wave Characteristics in a Rotated Cut of LiNbO₃ Crystal.

Theoretical study of the effect of uniaxial pressure on the propagation characteristics of plate modes as Lamb and SH waves in a lithium niobate plate is carried out. A change in the effective crystalline symmetry, as well as the effective elastic constants under the pressure influence, has been derived. The controlling coefficients describing the pressure influence on the plate modes' phase velocities are calculated for the various applications of uniaxial pressure.

Features of acoustic wave propagation in the Me/ZnO/Me/diamond waveguide structure.

The effect of mass loading on the phase velocities of the surface acoustic wave dispersion modes in the Me/ZnO/Me/diamond piezoelectric layered structure as a function of frequency, metallic, and piezoelectric layer thickness has been investigated. Aluminum, molybdenum, and platinum were considered as the metallic layer materials. It has been demonstrated that the change in the phase velocities substantially depends on the acoustic impedance of the metal layer and its thickness.

Temperature coefficients of elastic constants of trigonal, hexagonal, and tetragonal crystals.

Temperature coefficients of elastic constants (TC(IJ)) for trigonal, hexagonal, and tetragonal crystals have been obtained. The TC(IJ) of several trigonal, hexagonal, and tetragonal crystals have been calculated and compared with known experimental data. The nature of the anomalous TC66 of quartz has been discussed in detail.

Influence of the external electric field on propagation of Lamb waves in piezoelectric plates.

The influence of the electric field on the properties of the Lamb and SH-waves in piezoelectric Bi(12)GeO(20) and La(3)Ga(5)SiO1(4) crystal plates has been investigated. Using basic equations and boundary conditions, the formulas for computer simulation have been obtained. The effect of acoustic modes hybridization has been considered.