Ultrasonic microspectroscopy of LiNbO3 and LiTaO3 single crystals for SAW devices

Abstract

A new ultrasonic microspectroscopy system was developed for accurately and efficiently characterizing material properties under a highly stabilized measurement temperature environment. The system was applied to evaluating elastic homogeneities of commercially available 3‐inch‐diameter single crystals for surface acoustic wave (SAW) devices: 127.86°YX‐LiNbO3, 64°YX‐LiNbO3, 36°YX‐LiTaO3, and X‐112.2°Y LiTaO3. The slight variations in leaky SAW velocity along the pulling axis and the diameter on the water‐loaded specimen surfaces were successfully detected. Velocity variations of about 0.01% for LiNbO3 and 0.02% for LiTaO3 were obtained for SAW device substrates. The chemical composition distributions of 0.012 Li2O‐mol% for 127.86°YX‐LiNbO3 and 0.034 Li2O‐mol% for 36°YX‐LiTaO3 were evaluated by comparing the measured velocity variations with the sensitivities to chemical composition previously obtained. © 2000 Scripta Technica, Electron Comm Jpn Pt 2, 83(9): 8–21, 2000

Utilization of Permittivity Memory Effect for Position Detection of Shape Memory Piezoelectric Actuator

“…1) The utilization of their piezoelectric properties has led to the wide use of piezoelectric actuators for various applications. 2,3) Particularly, in recent years, ferroelectric materials have been expected to be applied in micro-electro-mechanical system (MEMS) devices because of their simple structure and high energy density. However, there are some serious problems with the application of MEMS devices in small wireless communication systems.…”