Optimized growth and characterization of cadmium oxalate single crystals in silica gel

摘要

Single crystals of cadmium oxalate hydrate have been grown in silica gel in the presence of divalent Cd~(2+)ions impregnated with oxalic acid at room temperature. Gel aging technique was adopted to reduce the nucleation density and hence larger and more perfect single crystals were harvested. Obtained crystals exhibit triclinic structure with unit cell dimensions a = 6.0059 A, b = 6.66 A, c = 8.49 A, alpha = 105.71 deg, beta = 98.99 deg and gamma = 74.66 deg. IR spectrum indicates the presence of oxalate ligands and water of crystallization. Thermal behavior and stability of the grown cadmium oxalate crystals were investigated in the temperature range of 30-600 deg C. A.C. electrical conductivity of Cd(C_2O_4) centre dot 3H_2O was measured for different frequencies and was found to lie between usual conductivities of semiconductor and insulator. The activation energy required to move permanent intrinsic defects in the crystal lattice was found and was equal to 0.15 eV.