Abstract:
Triglycine sulphate (TGS) single crystals have vest demand as an interesting material
both for academic research and industrial applications. In the present research, an attempt
has been made to grow TGS crystal in pure form and to study the effect of KCl as
impurities on various properties of TGS single crystals.
In this thesis work, pure and (0.2, 0.4, 0.6, 1 mol %) KCl doped TGS single crystals were
grown by natural evaporation method from aqueous saturated solutions. The presence of
various functional groups in the grown crystal is identified from Fourier transform
infrared (FTIR) spectrum analysis in the wavenumber region 4000 – 400 cm-1. Lattice
parameters were estimated by powder X-ray diffraction method. Optical characterization
has been done by recording the UV-Vis (both absorption and transmittance) spectra in the
wavelength range of 190 nm to 1100 nm.
Etching studies of (001) oriented pure and KCl doped TGS single crystals were carried
out using pure distilled water as an etchant at room temperature for 10s. The thermal
behavior has been investigated by thermogravimetric (TGA) and differential thermal
analysis (DTA) from room temperature to 600 °C. DC electrical conductivities were
measured in the temperature range of 35 °C to 100 °C. Dielectric constant was measured
by the parallel plate capacitor method using LCR meter in the frequency range (1- 400)
kHz. The microhardness measurements were carried out by Vickers microhardness tester.
The grown crystals were found to be stable, transparent, and colorless. The etch pits
changed by varying the doping concentration. The UV cut off of all crystals are found to
be 240 nm. The TGA and DTA show that the grown crystals are thermally stable up to
about 232 °C. The DC electrical conductivity is found to increase with the increase in
temperature and doping concentration. The value of dielectric constant decreases with the
frequency increases and also increases with the increase of doping concentration. Firstly,
hardness is increased for 0.2 mol % KCl doped TGS crystals and than it decreases with
the increase of more concentration level. The hardness also high upto 50 g loads and then
decreases with the increase of load.
