Optical, thermal, dielectric and mechanical studies on glycine doped potassium dihydrogen orthophosphate singles crystals grown by SR method

Abstract

Single crystals of glycine doped potassium dihydrogen orthophosphate (KDP) were grown by Sankaranarayanan-Ramasamy (SR) method with have a size of 20mm in diameter and 90mm in length. The grown crystals were subjected to powder X-ray diffraction (XRD), differential scanning calorimeter (DSC), thermo-gravimetric analysis (TGA), optical transmission, dielectric and Vickers microhardness studies. The TGA of the samples reveal that the grown crystals were stable up to 200°C at least for all samples. The important optical parameters such as reflection and extinction coefficients of the grown crystal were calculated and discussed. The variation of dielectric constant, dielectric loss, a.c. resistivity and a.c. conductivity with frequency of applied field in the range from 1kHz to 200 kHz was studied. The lower values of dielectric loss due to less of defect were observed in SR grown glycine doped KDP crystals. Vickers microhardness study shows higher mechanical stability in SR method grown crystals.