Lithium and Cesium Doping on the Properties of ZTS Crystals (Tris (Thiourea) Zinc (II) Sulphate)

Abstract

The influence of alkali metals (Cs and Li) doping on the properties and crystal growth of tris(thiourea)zinc(II)sulphate crystals by slow evaporation solution growth technique at 30ºC has been investigated. Each metals as dopant incorporate into the crystal lattice even at its low concentrations is well confirmed by energy dispersive X – ray spectroscopy (EDS). In the powder X –ray diffraction (XRD), high intense peaks are observed for all doped specimens due to stress developed in the crystal because of doping when compared to pure one. Single crystal XRD reveals a nominal increase in the cell parameter values of the doped samples compared to pure. Presence of each alkali metal (Li, Cs) quantitatively is confirmed by inductively coupled plasma (ICP) technique. It is interesting to observe the enhancement of fluorescence intensity of pure ZTS by the dopant in the photoluminescence (PL) spectra. The grown crystals are also characterized by FT-IR, UV-Visible and TG/DSC methods. The second harmonic generation (SHG) efficiency, an essential character required for the single crystals to identify the non-linear optical (NLO) property, was performed by kurtz powder technique. 2.The characterization results of influence of various concentration of Mn (II) ion on the properties and crystalline perfection of ammoniumdihydrogenphosphate (ADP) crystal are presented. Using water as a solvent pure, 1 and 20 mol % of Mn (II) ion in the form manganese (II) sulphate added ADP crystals are prepared by slow evaporation solution growth technique (SEST). Well faceted grown crystals are characterised by different experimental techniques. The presence of Mn (II) in the doped specimens is confirmed by energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma (ICP) technique. High resolution X- ray diffraction (HRXRD) study of the doped samples when compared with the pure ADP crystal reveals interesting features. In the single crystal XRD studies, the dopants have not altered the lattice parameter values and the crystal system of pure ADP. Reduction in the intensity of peaks is observed in the powder XRD of all the doped samples. It is interesting to enhancement of fluorescence intensity of pure ADP by the dopants in the photoluminescence (PL) spectra. The surface morphology of the crystals is studied by scanning electron microscopy (SEM). The grown crystals are also characterized by FT-IR, UV-Vis and TG/DTA methods. The second harmonic generation (SHG) efficiency, which is an essential character required for the single crystals to identify the nonlinear optical (NLO) property, is performed by Kurtz powder technique. Increasing in concentrations of dopant enhance the SHG efficiency of ADP crystal.