Optical, thermal and mechanical characterization of Al(III)/Sb(III)-doped tris(thiourea)zinc(II) sulphate crystals

The influence of Al(III)/Sb(III)-doping on the properties of tris(thiourea)zinc(II) sulphate (ZTS) crystals grown by slow evaporation solution growth technique is reported. The as-grown crystals belong to orthorhombic system and cell parameters are, a = 7.77 Å, b = 11.13 Å, c = 15.47 Å, V = 1338 Å3 (Al(III)-doped) and a = 11.1996 Å, b = 7.770 Å, c = 15.5598 Å, V = 1368.3 Å3 (Sb(III)-doped). The structure and the crystallinity of the materials are further confirmed by powder X-ray diffraction analysis. The modes of vibrations of different functional groups present are identified by Fourier transform infrared studies. Thermogravimetric/differential thermal analysis studies reveal the purity of the materials and no decomposition is observed up to the melting point. Surface morphological changes due to doping are observed by scanning electron microscopy. Microhardness study was carried out to elucidate the mechanistic behavior microhardness studies were carried out to elucidate the mechanistic behavior. Second harmonic generation activity is much better in the case of Sb(III)-doping. The specimen is also characterized by dielectric studies.