Large-sized crystal growth and piezoelectric properties of the single crystals of LiNa5Mo9O30

Abstract

Large-sized crystals of LiNa₅Mo₉O₃₀ with seeds in the a-, b- and c-directions were grown successfully by the top-seeded solution growth method. The relative dielectric constants were determined to be ε₁₁/ε₀ = 16.11, ε₂₂/ε₀ = 10.52, and ε₃₃/ε₀ = 16.78, respectively. A complete set of elastic and piezoelectric constants of the LiNa₅Mo₉O₃₀ single crystal was determined by means of a resonance technique and impedance analysis at room temperature. The results show that the LiNa₅Mo₉O₃₀ crystal possesses five piezoelectric constants (d₁₅ = 0.14 pC N⁻¹, d₂₄ = 2.32 pC N⁻¹, d₃₁ = 0.17 pC N⁻¹, d₃₂ = 0.20 pC N⁻¹, d₃₃ = 1.20 pC N⁻¹). As a polar crystal, the octahedral distortion and dipole moment of MoO₆ in LiNa₅Mo₉O₃₀ are analyzed and calculated to explain the relationship between the piezoelectric properties and the structure.