Effect of Rare Earth Impurities on the Growth of Ammonium Oxalate Monohydrate Single Crystals

Abstract

Single crystals of Ammonium Oxalate monohydrate (AO) were grown from aqueous solution in pure form and in presence of Ethylenedinitrilotetraacetic acid (EDTA) and some rare earth impurities like Sm+3, La+3, Gd+3 by the slow cooling method. Well faceted AO crystals with the dimensions of 1.0 x 1.0 x 2.0 cm3 were obtained. X-ray diffractometry, Fourier transform infrared (FT-IR) spectroscopy and Vicker’s microhardness measurements were carried out to study the structural and mechanical properties of the grown crystals. FT-IR spectra confirmed the presence of different vibrational modes of oxalate group in the grown samples. X-ray diffraction analysis confirmed the crystalline structure of the grown samples of which the pure specimen showed good agreement with the standard data. The microhardness study showed a significant increase in hardness values of AO crystals grown in presence of impurities.