Effect of copper on growth, structural, optical, and thermal studies of lithium ammonium sulphate crystals grown by slow evaporation method

Effects of the addition of 1.5 mol% CuSO4 on the growth and the various properties of Lithium Ammonium Sulphate (LAS) single crystals grown by the slow evaporation solution growth technique have been studied. The grown crystals were characterized by single crystal X- Ray Diffraction analysis (XRD), Fourier Transform Infrared spectral studies (FT-IR), UV-Vis- NIR, Atomic Absorption Study (AAS), Thermal analysis and Micro hardness studies. It is observed that the intensity of the plane (111) in pure LAS increases with that of CuSO4-doped LAS increases than in the pure LAS crystal. The strong peak for both crystals in the region 1120 -1130 cm-1 in FTIR spectra corresponds to the SO42- symmetric stretching modes. UV-Vis-NIR spectra revealed that absorption occurs at 205 nm. The metal contents in the doped LAS crystals were estimated as 662 ppm from the Atomic Absorption studies. Thermal studies indicate that the decomposition temperature of the crystal are decreased in CuSO4 - doped LAS crystals. Vicker’s micro hardness study reveals that the addition of CuSO4 increases the hardness of the crystal.