Saw and pseudo SAW properties of NdCa4O(Bo3)3 crystal

The surface acoustic wave (SAW) and pseudo SAW properties of NdCa₄O(BO₃)₃ crystal were measured for the first time in the temperature range from -10degC to 100degC. For SAW, the largest electromechanical coupling coefficient of about 0.7% was obtained for the y-x orientation, while for the pseudo SAW the above coefficient was about 1.4% for the x-y and z-y orientations. For the y-x orientation, a second-order temperature coefficient of frequency and a turnover temperature of about -50 ppb/degC² and 43degC, respectively, were obtained. Other investigated orientations showed approximate linear frequency changes against temperature for both SAW and pseudo SAW. This crystal is promising for application in low-loss temperature stable SAW devices and for high-temperature sensors.