YZ-lithium niobate is a crystalline material belonging to the trigonal group (class 3m). The...

YZ-lithium niobate is a crystalline
material belonging to the trigonal group (class 3m). The piezoelectric coupling
coefficient and the permittivity matrices are given by

The elastic constants in
units of 1010N/m2 , as well as the piezoelectric and relative permittivity
constants are c11 = 20.3, c33 = 24.5, c44 = 6, c12 = 5.3, c13 = 7.5, c14 = 0.9,
e15 = 3.7C/m2 , e22 = 2.5C/m2 , e31 = 0.2C/m2 , e33 = 1.3C/m2 , ε11 = 44 ×
ε0 and ε33 = 29 × ε0. The density of the material is ρ =
4700kg/m3 . The velocity of propagation of the SAW in the material is aR = 3488
m/s. The direction of propagation is the z axis, and the free surface is a
plane normal to the y axis. Determine the electromechanical coefficient and the
stiffened elastic coefficients, given that the applied electric field is in a
direction normal to the free surface (2-direction). Hence, compute the increase
in the SAW velocity due to the stiffening effectSt-quartz is a crystalline
material belonging to the trigonal group (class 32). The elastic constants in
units of 1010N/m2 , as well as the piezoelectric and relative permittivity
constants are c11 = 8.674, c33 = 10.72, c44 = 5.794, c12 = 0.699, c13 = 1.191,
c14 = −1.791, e11 = 0.171C/m2 , e14 = −0.0436C/m2 , ε11 = 4.5
× ε0 and ε33 = 4.6 × ε0. The density of the material is ρ =
2651kg/m3 . The velocity of propagation of the SAW in the material is aR = 3158
m/s. Determine the electromechanical coefficient and the stiffened elastic
coefficients, given that the applied electric field is in a direction normal to
the free surface (2-direction). Hence, compute the increase in the SAW velocity
due to the stiffening effect.