Title :
Quasilongitudinal pseudosurface acoustic waves in trigonal crystals
Author_Institution :
Inst. of Radio Eng. & Electron., Acad. of Sci., Moscow, Russia
Abstract :
Quasilongitudinal pseudosurface acoustic wave (QLPSAW) progresses along a solid surface at a velocity exceeding those of the two slowest bulk waves and radiates them. Calculated properties of the wave in the X-axis direction of La3Ga5SiO14 and of SiO2 as well as on some doubly rotated cuts of LiNbO3 and LiTaO3 are discussed. Along the [100] axis of langasite QLPSAW is found, its velocity is less than that of longitudinal bulk wave and its attenuation coefficient is about 10 dB/wavelength. QLPSAW can exist in the same direction of quartz crystal too, but its velocity is greater than the fastest bulk wave speed, and attenuation is of the order of 10-3-10-2 dB/wavelength. In lithium niobate and lithium tantalate crystals directions of possible existence of QLPSAW form bounded regions. Attenuation of the wave tends to zero at the boundaries of the regions and its phase velocity is close to the speed of the longitudinal bulk wave
Keywords :
ferroelectric materials; lanthanum compounds; lithium compounds; quartz; surface acoustic waves; ultrasonic absorption; ultrasonic propagation; ultrasonic velocity; La3Ga5SiO14; LiNbO3; LiTaO3; QLPSAW; SiO2; X-axis direction; attenuation coefficient; doubly rotated cuts; langasite; lithium niobate; lithium tantalate crystals; phase velocity; quartz crystal; quasilongitudinal pseudosurface acoustic waves; slowest bulk waves; solid surface; trigonal crystals; velocity; Acoustic propagation; Acoustic waves; Anisotropic magnetoresistance; Attenuation; Crystals; Glass; Lithium; SAW filters; Solids; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-2940-6
DOI :
10.1109/ULTSYM.1995.495567
