Optical and thermal properties of grown bulk ZnMgS mixed crystals

•The growth of Zn1−xMgxS mixed crystals was done using the Bridgman method.•The photopyroelectric calorimetry (PPE) technique was used to conduct the thermal analysis of Zn1−xMgxS alloys.•The thermal and optical parameters showed a sensitivity to the fabrication process and the crystals’ quality.•The effect of magnesium on thermal and optical properties was examined and discussed. This work investigates the optical and thermal properties of zinc sulfide ZnS single crystal mixed with magnesium (Zn1−xMgxS). The starting material’s Mg mass ratio (x) varied from x = 0 to x = 0.34. The investigated alloys were grown using the vertical modified Bridgman method. The SEM/EDS method was used to check the accurate composition of the crystals. X-ray diffraction analysis was applied to check the phase and crystallinity of the grown alloys. The band gap energy was measured for each sample by transmission spectroscopy. The dynamical thermal properties were measured using photopyroelectric calorimetry (PPE). The thermal diffusivity and effusivity values were extracted from the experiment, allowing the calculation of the specimens’ thermal conductivity. The optical and thermal properties of grown Zn1−xMgxS crystals versus composition were discussed.