Cobalt niobate (CoNb2O6) powders have been prepared using a mixed oxide synthesis route. The formation of the CoNb2O6 phase in the calcined powders has been investigated as a function of calcination conditions by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. The morphological evolution was determined by scanning electron microscopy (SEM). It has been found that the minor phases of unreacted Co3O4 and the orthorhombic-Nb2O5 and monoclinic-β-Nb2O5 phase tend to form together with the columbite CoNb2O6 phase, depending on calcination conditions. It is seen that optimization of calcination conditions can lead to a single-phase orthorhombic CoNb2O6. The calcination temperature and dwell time have been found to have a pronounced effect on the phase formation of the calcined cobalt niobate (CoNb2O6) powders. Optimization of calcination conditions can lead to a single-phase CoNb2O6 in a columbite phase.

Keywords: CoNb2O6, Calcination, Powder synthesis.