Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly

2007   Vol. 8   No. 4   p. 669~674

New solutions of shear waves in piezoelectric cubic crystals

ZAKHARENKO A.A.

(International Institute of Zakharenko Waves, Krasnoyarsk-37, 17701, Krasnoyarsk 660037, Russia)
E-mail: aazaaz@inbox.ru
Received Dec. 15, 2006 revision accepted Feb. 12, 2007

Abstract: Acoustic wave propagation in piezoelectric crystals of classes 43m and 23 is studied. The crystals Tl₃VS₄ and Tl₃TaSe₄ (43m) of the Chalcogenide family and the crystal Bi₁₂TiO₂₀ (23) possess strong piezoelectric effect. Because the surface Bleustein-Gulyaev waves cannot exist in piezoelectric cubic crystals, it was concluded that new solutions for shear-horizontal surface acoustic waves (SH-SAWs) are found in the monocrystals using different electrical boundary conditions such as electrically “short” and “open” free-surfaces for the unique [101] direction of wave propagation. For the crystal Tl₃TaSe₄ with coefficient of electromechanical coupling (CEMC) K_e²=e²/(C×g)~1/3, the phase velocity V_ph for the new SH-SAWs can be calculated with the following formula: V_ph=(V_a+V_t)/2, where V_t is the speed of bulk SH-wave, V_t=V_t4(1+K_e²)^1/2, V_a=a_KV_t4, a_K=2[K_e(1+K_e²)^1/2−K_e²]^1/2, and V_t4=(C₄₄/ρ)^1/2. It was found that the CEMC K² evaluation for Tl₃TaSe₄ gave the value of K²=2(V_f–V_m)/V_f~0.047 (~4.7%), where V_f~848 m/s and V_m~828 m/s are the new-SAW velocities for the free and metallized surfaces, respectively. This high value of K²(Tl₃TaSe₄) is significantly greater than K²(Tl₃VS₄)~3% and about five times that of K²(Bi₁₂TiO₂₀).

Key words: New shear-horizontal surface acoustic waves (SH-SAWs), Strong piezoelectric effect, Piezoelectric cubic crystals, Solutions for latent waves
doi:10.1631/jzus.2007.A0669             CLC number: O735

References:

[1] Bleustein, J.L., 1968. A new surface wave in piezoelectric materials. Applied Physics Letters, 13(12):412-413.

[2] Gulyaev, Y.V., 1969. Electroacoustic surface waves in solids. Soviet Physics Journal of Experimental and Theoretical Physics Letters, 9:37-38 (in Russian).

[3] Gulyaev, Y.V., Hickernell, F.S., 2005. Acoustoelectronics: history, present state and new ideas for a new era. Acoustical Physics Reports, 51(1):101-110 (in Russian).

[4] Henaff, J., Feldmann, M., Kirov, M.A., 1982. Piezoelectric crystals for surface acoustic waves (Quartz, LiNbO₃, LiTaO₃, Tl₃VS₄, Tl₃TaSe₄, AlPO₄, GaAs). Ferroelectrics, 42:161-185.

[5] Kamenov, V.P., Hu, Y., Shamonina, E., Ringhofer, K.H., Gayvoronsky, V.Y., 2000. Two-wave mixing in (111)-cut Bi₁₂SiO₂₀ and Bi₁₂TiO₂₀ crystals: characterization and comparison with the general orientation. Phys. Review E, 62(2):2863-2870.

[6] Kessenikh, G.G., Shuvalov, L.A., 1982. Transverse surface waves in piezoelectric crystals of classes 622 and 422. Ferroelectrics, 42:149-152.

[7] Maerfeld, C., Tournois, P., 1971. Pure shear elastic surface wave guide by the interface of two semi-infinite media. Applied Physics Letters, 19(4):117-118.

[8] Wu, Z., Cohen, R.E., 2005. Pressure-induced anomalous phase transitions and colossal enhancement of piezoelectricity in PbTiO₃. Physical Review Letters, 95:037601.

[9] Zakharenko, A.A., 2005. Love type waves in layered systems consisting of two piezoelectric cubic crystals. Journal of Sound and Vibration, 285(4-5):877-886.