The thermal decomposition of monohydrated ammonium oxotris(oxalate)niobate

The thermal decomposition in argon of the morrohydrated ammonium tris(oxalate)niobate, (NH4)(3)NbO(C2O4)(3).H2O, has been studied by TG/DTG, DTA, DSC, IR absorption and XRD. The material decomposes stepwise by the release of CO, CO2, NH3 and water. The atomic structure of the complex. initially becomes amorphous and then crystallizes twice in the form of orthorhombic and monoclinic niobium pentoxide.