Investigation into the optimized growth, anisotropic properties and theoretical calculations of the polar material Cs2TeW3O12

Abstract

Recent research on cesium tellurium tungstate (Cs₂TeW₃O₁₂) has demonstrated that it is a promising candidate for use in photoelectric applications. However, further improvement, particularly for the study of the anisotropic properties of Cs₂TeW₃O₁₂, is hampered by the difficulty of bulk crystal growth. Here, single crystals of the polar compound Cs₂TeW₃O₁₂ with dimensions reaching 75 mm × 35 mm × 8 mm were grown successfully through a modified top-seeded solution growth (TSSG) method. Laue diffraction and high-resolution X-ray diffraction (HRXRD) measurements indicate that the Cs₂TeW₃O₁₂ crystals are of high crystalline quality. Optical measurements demonstrate a UV absorption edge near 385 nm, with a transmittance window reaching 5.5 μm. Using a large high-quality crystal, the thermophysical properties including specific heat, thermal diffusion and thermal conductivity were also systematically studied. More importantly, the Raman scattering properties determined using spontaneous Raman spectroscopy show that the Cs₂TeW₃O₁₂ crystal exhibits an intense Raman shift (910.34 cm⁻¹) and narrow line-width (6.84 cm⁻¹) that are comparable to those of the YVO₄ crystal. In addition, first-principles calculations have been performed to better understand the structure–property relationships of the Cs₂TeW₃O₁₂ crystal. These attributes may establish a foundation for future nonlinear optical applications of Cs₂TeW₃O₁₂ crystals.