Mixed crystals of potassium-ammonium zinc chloride in different concentrations were grown from aqueous
solution employing the techniques of slow cooling and controlled evaporation. Powder x-ray diffraction
studies were carried out on the grown crystals. The comparison between lattice parameters a, b and c are
experimentally determined and calculated by Vegad's law. The concentration of K+ ions in the crystals was
measured by the atomic absorption technique. The crystal morphology changed considerably by increasing
K+ concentration. The optical absorption coefficient (α) indicated strong influence changing concentration.
The optical energy gap was found to decrease with increasing K+ concentration.