Enhancement of structural perfection of alkali halide single crystals by doping with copper

The pure and copper (Cu+) doped alkali halide single crystals have been grown from melt by using the Czochralski (Cz) method. The optical absorption studies confirm that the doped copper is incorporated with the grown crystals. The effect of doping on crystalline perfection of grown crystals was analyzed by high resolution X-ray diffraction (HRXRD) measurements. The HRXRD results clearly reveal that the Cu+ doped crystals are having higher crystalline perfection than pure crystals. The mechanical behavior of the grown crystals was measured by the Vickers microhardness measurement. The hardness value of the crystals increases with an increase in load and thereafter it becomes independent of the applied load. The Meyer index number and hardness using Hays–Kendall approach of pure and doped crystals were calculated and tabulated.

► Pure and impurity doped alkali halide single crystals were grown from melt using the Czochralski technique. ► Crystalline perfection and mechanical properties of the grown crystal are discussed in detail. ► Crystalline perfection of Cu+ doped crystals was found to be excellent as compared to the respective pure crystals.