Temperature Compensated Piezoelectric Materials
Interim technical rept. No. 2, 1 Jul-31 Dec 1975
PENNSYLVANIA STATE UNIV STATE COLLEGE MATERIALS RESEARCH LAB
Pagination or Media Count:
In order to search for new temperature compensated materials for surface acoustic wave SAW devices with low ultrasonic attenuation and high electromechanical coupling, the following experimental and theoretical investigations were carried out i Extensive crystal growth investigations were carried out for Li2SiO3, Ba2Si2TiO8, and Pb2KNb5O15, using both Bridgman and Czochralski methods. ii The on-diagonal elastic constants c11, c22, c33, c44 and c55 and their temperature coefficients have been measured for Pb2KNb5O15. The temperature coefficient of c11 is positive, indicating that temperature compensated cuts should exist for this material. iii The theoretical equations required for the experimental determination of the complete set of piezoelectric constants from X-ray measurements have been derived. For all 20 crystal classes exhibiting the piezoelectric effect explicit expressions are given for the longitudinal and transverse piezoelectric effect, corresponding to parallel-field and perpendicular-field reflection, respectively.
- Line, Surface and Bulk Acoustic Wave Devices
- Acoustooptic and Optoacoustic Devices
- Solid State Physics