ALKALINE-EARTH CU(II) OXALATE COMPOUNDS AS PRECURSORS OF MCUO2 (M = CA, SR, BA) OXIDES - THERMAL AND SPECTROSCOPIC STUDY

Three new calcium, strontium and barium oxalates, CaCu(C2O4)2.2H2O, SrCu(C2O4)2.4H2O, and BaCu(C2O4)2.6H2O, have been obtained. The thermal behaviour of these complexes has been studied by thermogravimetry and differential scanning calorimetry, showing the occurrence of three consecutive steps. Considering these results, the compounds were heated at different temperatures to get alkaline-earth copper oxides. This method of synthesis results in soft treatments, involving shorter reaction times and lower temperatures to obtain the corresponding mixed oxides, MCuO2 (M = Ca, Sr and Ba).