Growth and thermal properties of SrWO4 single crystal.

A strontium tungstate (SrWO₄) single crystal with dimensions of [uppercase_phi_synonym] 25×40 mm² has been grown by the Czochralski method using an iridium crucible. X-ray powder diffraction results show that as grown the SrWO₄ crystal belongs to the tetragonal system in the scheelite structure. The effective segregation coefficients of elemental W and Sr in the crystal growth are measured by x-ray fluorescence, and the respective values are close to 1. The thermal properties of the SrWO₄ crystal were systemically studied by measuring the thermal expansion, specific heat, and thermal diffusion coefficient. These results show that the crystal possesses a large anisotropic thermal expansion with thermal-expansion coefficients α_a=8.61×10^-6/K, α_b=8.74×10^-6/K, α_c=18.78×10^-6/K over the temperature range of 303.15–773.15 K. The measured value of the specific heat is 0.30–0.34 J g^-1 K^-1 when the temperature is increased from 323.15 to 1073.15 K. The thermal diffusion coefficient was measured over the temperature range of 303.15–543.15 K. The thermal conductivities of the SrWO₄ crystal along the [100] and [001] directions are calculated to be 3.1326 W m^-1 K^-1 and 2.9477 W m^-1 K^-1, respectively, at 303.15 K. Then the thermal properties of some other Raman crystals were compared with these data, and the thermal focal lengths for these crystals were also estimated. [ABSTRACT FROM AUTHOR]