Thermal decomposition of ammonium bis-oxalatodiaquaindate(III)

Indium(III) was precipitated with oxalic acid in the presence of ammonium n itrate maintaining an over all concentration of 0.125 M in HNO3. The chemic al analysis of the complex salt obtained corresponded with the formula, NH4 [In(C2O4)(2)]. 2H(2)O. Thermal decomposition studies of the complex indicat ed the formation of intermediates: ammonium indium oxalate and indium(III) oxalate and the final product to be indium(III) oxide. The isothermal decom position, infrared absorption spectra, and X-ray diffraction patterns have been used to characterise the complex and the intermediate product of therm al decomposition. (C) 2001 Elsevier Science B.V. All rights reserved.