Growth and characterization of cerium lanthanum oxalate crystals grown in hydro-silica gel

Single crystals of mixed cerium lanthanum oxalate (CLO) are grown by gel method. Over the hydrosilica gel prepared by mixing oxalic acid and sodium meta silicate, a mixture of aqueous solutions of cerium nitrate and lanthanum nitrate are poured gently. Cerium and lanthanum ions diffuse into the gel and react with oxalic acid to give colorless, transparent cerium lanthanum oxalate crystals with in a few days. Different growth parameters give crystals of various dimensions. Infrared (IR) spectrum confirms the presence of water molecules and carboxylic acid. X-ray diffraction (XRD) pattern of these samples reveals the crystalline nature. Diffraction peaks are indexed. Unit cell parameters are determined. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) data support the presence of 9 H2O molecules attached to the CLO crystal lattice which are lost around 200 degreesC as revealed by the endotherm record. Exothermic peak around 350 degreesC-425 degreesC shows the release of CO and CO2. Elemental analysis done by energy dispersive X-ray fluorescence analysis (EDXRF) for the mixed rare earth compound is almost in good agreement with experimental and theoretical values.