TITLE:
Structural, Optical, Electrical and Thermal Characterizations of Pure and L-alanine Doped Ammonium Dihydrogen Phosphate Crystals
AUTHORS:
Ferdousi Akhtar, Jiban Podder
KEYWORDS:
Amino Acid, Solution Growth, Decomposition, Electrical Conductivity, Optical Transmission
JOURNAL NAME:
Journal of Crystallization Process and Technology,
Vol.1 No.2,
August
2,
2011
ABSTRACT: Pure ammonium diyidrogen phosphate and L-alanine doped ammonium diyidrogen phosphate crystals were grown from aqueous solutions by natural evaporation process. The grown crystals are characterized by Fourier Transform Infrared spectroscopy, Energy Dispersive X-ray, UV-visible spectroscopy and differential thermal analysis. Crystal structure has been studied by powder X-ray diffraction. Pure and doped crystals both possessed tetragonal structure. The optical transparency is found to increase with the increase of doping concentration in the grown crystals and band gap energies of all crystals have been calculated at their cut off frequencies. It is found that the optical band gap increases with doping concentrations. D.C.electrical conductivity of grown crystals along the growth axis was carried out at temperatures ranging from 35-140°C by the conventional two-probe method. The conductivity of the crystals increases with temperature and also increases with the L-alanine concentration. The decomposition temperatures and weight loss have been estimated from the Thermo Gravimetric Analysis and Differential Thermal Analysis and hardness was found from the Vicker’s microhardness measurement.