The complex Rb2[Mo2O5(C2O4)2(H2O)2] (RMO) was prepared and characterized by means of chemical analysis and IR spectral studies. Its thermal decomposition was studied by using TG and DTA techniques. RMO loses its water between 160 and 200°C, this immediately being followed by the decomposition of anhydrous RMO, which takes place in three stages. The first two stages occur in the temperature ranges 200–220 and 220–255°, to give intermediates with tentative compositions Rb8[Mo8O22(C2O4)6] and Rb8[Mo8O26(C2O4)(CO3)], respectively, the latter then decomposing in the third stage between 255 and 340° to give the end-product, rubidium dimolybdate (Rb2Mo2O7). Thed spacings for Rb2Mo2O7 are given for 2θ values between 10 and 70°.
Neodymium zirconyl oxalate (NdZrOX) is prepared and characterized by chemical analysis and ir spectral studies. Its thermal decomposition has been investigated by using DTA, TG, DTG, X-ray diffraction and ir spectroscopy. On the basis of thermogravimetry and isothermal studies a probable mechanism for the decomposition is proposed. The decomposition proceeds mainly through three stages: i) dehydration between RT-413 K, ii) decomposition of oxalate between 413–943 K and iii) decomposition of the carbonate between 1028–1235 K to give a mixed oxide. The ir spectra and X-ray diffraction studies are made for identification of the intermediates. X-ray diffraction studies of the end product indicates that it belongs to cubic crystal system witha=11.520 Å.