Optical second harmonic generation studies of pure and glycine-doped bisthiourea copper/cadmium adipates

The bisthiourea copper and cadmium adipate (BTCu/CdA), and their glycine-doped derivatives (BTCu/CdA-Gly) have been synthesized by simple mechanochemical method. The chemical compositions of synthesized materials were confirmed by chemical and elemental analysis. The uniform integration of glycine in doped materials was determined by EDAX and FTIR techniques. FTIR studies revealed the coordination of metal ion to thiourea through sulphur atom. The SEM images of glycine-doped materials demonstrated comparatively smoother morphology with crystalline decorations than the pure materials. In TG–DTA studies, the thermal stability of BTCdA-Gly is found to be highest (105 °C). On glycine doping, the optical transmission of the pure compounds shifted towards lower cut-off wavelengths (319.76 to 288.31 nm) with the significant gain in transmittance. In the NLO property studies of the materials in terms of dielectric studies, the dielectric constant and dielectric loss values were observed to decrease with the increase in frequency. The SHG conversion efficiency was measured by standard Kurtz–Perry powder technique. The SHG conversion efficiency of BTCuA-Gly and BTCdA-Gly was found to be 4.28 and 1.037 times higher than standard KDP. The observed SHG conversion efficiency demonstrated the superior NLO property of the doped materials.