Investigation on recent quartz like materials for SAW applications

Recent progress on growing and characterizing quartz like materials of the trigonal system class 32 has been reported by several groups. The promising perspective for bulk acoustic wave frequency control applications indicates the potentiality of employing these materials for SAW applications as well. This paper reports results of investigations focused on SAW orientations of langasite (LGS), gallium phosphate (GaPO/sub 4/), and langanite (LGN), both single and doubly rotated cuts. Among the characteristics explored, major attention is paid to the temperature coefficient of delay (TCD), the electromechanical coupling coefficient (K/sup 2/), and the power flow angle (PFA). Three-dimensional graphics and contour graphics are plotted based on our calculated results, showing the regions in space where low TCD and high K/sup 2/ can be obtained, also exhibiting the associated PFA and phase velocity characteristics. The influence of different sets of material constants is addressed where appropriate. The spatial investigation performed shows that there are promising orientation regions in these materials where zero or reduced TCD (