Studies on solid-state decomposition of calcium tetraaquatris(oxalato) lanthanate(III)pentahydrate using DTA-TG in air and DSC in nitrogen

摘要

Heterobimetallic oxalate complex precursor, Ca3[La(C _2O_4)_3(H_2O)_4] _2·5H_2O (CaOLa) was synthesized in aqueous medium and characterized by elemental analysis, IR, electronic spectral, and powder X-ray diffraction studies. It is found to be fined crystalline in nature with triclinic symmetry. Thermal studies (TG, DTG, and DTA) in air showed that the departure of aqua ligands completed at ca. 240 C. A mixture of mainly CaO, La_2O_3, and La_2CaO _x along with a trace of carbides of calcium and lanthanum were identified in the end products at 1,000 C. The nature of decomposition in nitrogen was explored from DSC study and discussed the evaluated kinetic parameters.