2020 Volume 128 Issue 3 Pages 130-134
We present a relationship between piezoelectric property and crystal structure in melilite-type crystals. Two independent piezoelectric constants, d14 and d36, increase and decrease with the polyhedral distortion, respectively. Based on this knowledge, single crystals made of strontium-substituted calcium magnesium silicate Ca2MgSi2O7 (CMS) have been submitted to the Czochralski method, which made them grown. The CMS crystal has a high d36; however, its transition temperature is around 85 °C. Therefore, the strontium substitution is conducted to decrease this phase transition temperature. A single crystal of strontium substituted CMS, with nominal chemical composition Ca1.7Sr0.3MgSi2O7 (CSMS30), shows no phase transition when temperature rises from room to melting temperature. Its piezoelectric d′31 constant is 2.1 pC/N and its compressive strength is 830 MPa on crystal substrate with (ZXt)45° cut. The CSMS30 single crystal is a superior candidate material for pressure sensors at high operating temperatures.