Electro-elastic properties of a piezoelectric Te2O(PO4)2 crystal

Abstract

A phosphate piezoelectric crystal Te₂O(PO₄)₂ (TPO) was grown by the Czochralski method. The dielectric, piezoelectric, and elastic constants of the crystal were measured. The TPO crystal features a large longitudinal piezoelectric constant of d₃₃ = 6.6 pC N⁻¹, much better than that of GaPO₄ and AlPO₄. The structure–property relationships are discussed in detail. First-principles calculations and structural analysis revealed that the introduction of distorted [TeO₅] groups into phosphates is beneficial for enhancing the piezoelectric properties of phosphate crystals. Furthermore, the temperature dependence of the resistivity and piezoelectric constant was also measured. The results suggest that TPO is a potential candidate for piezoelectric applications due to its large piezoelectric coefficient, good piezoelectric temperature stability, and ease in crystal growth.