4 inch langasite crystals grown along SAW-cut orientations.

Langasite crystal is an important substrate material for intermediate frequency surface acoustic (IF-SAW) wave filters and high temperature sensors, due to their high piezoelectric constants, electromechanical coupling factor and no phase transformation up to the melting point. In this work, 3 and 4 in. circular shaped langasite crystals along SAW-cut orientations (0°, 22°, 90°) and (0°, 138.5°, 26.6°) were grown successfully. Key parameters to grow high quality crystals are discussed. Rocking curve and frequency tests show a high homogeneity of these crystals. Homogeneous langasite crystals grown along a SAW-cut orientation with controlled shape are of enormous commercial value. [ABSTRACT FROM AUTHOR]