Structural investigation and scintillation properties of Cd1−xZnxWO4 solid solution single crystals

Abstract

A strategy for Cd_1−xZn_xWO₄ (x < 0.5) solid solution growth was successfully achieved by the Czochralski method. Polycrystalline samples and crystals of the Cd_1−xZn_xWO₄ system were studied using X-ray diffraction. Furthermore, the scintillation properties of Cd_1−xZn_xWO₄ (x < 0.5) crystals were investigated. It was found that the diffraction peaks of the polycrystalline Cd_1−xZn_xWO₄ (x = 0–1.0) system shift toward higher 2θ angles with increasing degree of Zn substitution. A linear relation between the zinc composition x and the lattice parameters of Cd_1−xZn_xWO₄ crystals existed. With increasing zinc content x, the lattice parameters a, b, and c decrease, and the volume of the unit cell decreases. The shift of the lattice parameter presents a trend from CdWO₄ to ZnWO₄. Energy dispersive X-ray (EDAX) analysis was carried out in order to confirm the composition of Cd_1−xZn_xWO₄ single crystals (x < 0.5). Optical measurements revealed that the solid solution crystals had a high optical transmittance of about 65% in the range of 350–600 nm, and the absorption edges of Cd_1−xZn_xWO₄ crystals exhibit increasing peaks from 317.4 nm to 321.5 nm. The emission peaks showed a red shift from 465.4 nm to 501.2 nm with the increasing content of zinc. Furthermore, it was observed that the light output (L.O.) decreases and the energy resolution (E.R.) increases with the increase in zinc content.