Synthesis, characterization and heat capacities of ternary oxides in the Ti-Nb-O system

Three different ternary oxides TiNb2O7, Ti2Nb10O29 and TiNb24O62 were prepared by solid-state reaction route and characterized by X-ray powder diffraction method. The standard molar heat capacities of these oxides were measured in the temperature range 125-850 K using differential scanning calorimetry. Since, the deviation from additive oxide was found to be insignificant, the low temperature values were extrapolated to 0 K using Debye extrapolation method and smoothed heat capacities data for temperature range 0-850 K were generated using a six-term fitting equation based on Debye and Einstein functions. By employing these smoothed heat capacities data the thermodynamic data tables were generated for all three oxides. (C) 2014 Elsevier B.V. All rights reserved.