Large size crystal growth and structural, thermal, optical and electrical properties of KCl1−xBrx mixed crystals

Large size and high quality KCl1−xBrx mixed crystals [with x = 0.0 (pure KCl), 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0 (pure KBr)] have been grown with suitable raw material proportion by the melt (Czochralski) method using the miscible alkali halides KCl and KBr. The grown crystals have been characterized by determining their density, refractive index, lattice constant, chemical composition, thermal parameters (Debye-Waller factor, Debye temperature and Debye frequency), optical absorption, micro hardness and electrical parameters (dielectric constant, dielectric loss factor, AC, and DC electrical conductivities and AC, and DC activation energies) through X-ray diffraction, optical, mechanical and electrical (both AC and DC at various temperatures in the range 30-150 °C) measurements. Results obtained in the present study indicate that mixing KCl with KBr leads to significant tuning of thermal, optical, mechanical and electrical properties without disturbing the crystal structure. The dielectric constant is found to increase several times due to mixing and KCl0.5Br0.5 crystal has the maximum value.