Optimized growth and electro-elastic properties of centimeter-sized piezoelectric crystals of Na2TeW2O9

Abstract

Large sized crystals of Na₂TeW₂O₉ with dimensions up to 75 × 35 × 25 mm³ were successfully grown using an optimized top-seeded solution growth method. The as-grown Na₂TeW₂O₉ single crystal exhibits well-developed faces with the major forms {200}, {002}, {202}, and {220}, which are in superior accordance with the ideal morphology predicted by the Bravais–Friedel and Donnay–Harker methods. A complete set of room temperature elastic, dielectric, and piezoelectric constants of Na₂TeW₂O₉ single crystals was determined using resonance techniques and impedance analysis. Our results show that Na₂TeW₂O₉ exhibits excellent piezoelectric properties (d₁₅ = −23.93 pC N⁻¹, d₂₄ = −20.34 pC N⁻¹), making the crystal a promising candidate for piezoelectric applications. The relationship between the piezoelectric properties and the crystal structure is also discussed.