Optimizing growth, structure, and elastic-electrical properties of acentric melilite CaYAl3O7 crystal

A new melilite single crystal CaYAl3O7 with dimensions of Φ26 × 60 mm3 has been grown successfully by the Czochralski method, taking into consideration as a potential high-temperature piezoelectric crystal for the first time. The rocking curve measurements indicate that the as-obtained CaYAl3O7 crystal is of high quality with a full width at half-maximum (FWHM) of 42.1 arcsec from the (001) reflection. The complete set of room temperature dielectric, elastic, and piezoelectric constants of CYAM crystal were determined using resonance techniques and impedance analysis. Our results show the piezoelectric strain constants d14 and d36 are 12.6 and 2.18 pC/N, respectively, with the corresponding electromechanical coupling coefficients of k14 = 18.06% and k36 = 5.45%, indicating the crystal is a promising candidate for piezoelectric applications. The structural polyhedron distortions dipole moments of CYAM crystal were analyzed in detail, and the relationship between the crystal structure and the piezoelectric properties has also been discussed.