Growth and high-temperature electromechanical properties of Ca3NbX3Si2O14 (X=Ga and Al) piezoelectric crystals

Piezoelectric single crystals of Ca3NbX3Si2O14 (CNXS, X=Ga and Al) with ordered langasite structure were successfully grown using the Czochralski technique. The structure was analyzed by X-ray powder diffraction, and the lattice parameters for CNAS were found to decrease slightly when compared to CNGS, due to the smaller ion radius of Al. The dielectric, piezoelectric and electromechanical properties were studied as function of temperature from 30 ∘C to 900 ∘C, showing a stable temperature-dependent behavior. Of particular significant is their high mechanical quality factor and electrical resistivity at elevated temperature, demonstrating CNXS crystals to be promising candidates for high-temperature applications.