STABILITY OF V4-TIO2, RUTILE SOLID-SOLUTIONS AT HIGH-TEMPERATURE()

V4+-TiO2 rutile solid solutions in the TiO2-V2O5, Al2O3-TiO2-V2O5, and Cr2O3-TiO2-V2O5 systems have been synthesised by high temperature cal cination of mixed powders and the resulting materials characterised by X-ray diffraction, vanadium analysis, CIELAB parameter measurements, electron paramagnetic resonance (EPR), and uv to ir (UV-IR) spectrosco py. The variation of rutile unit cell parameters with sample compositi on indicated that rutile solid solutions had formed in all the systems studied. EPR and UI-IR spectroscopy showed the presence of V4+ ions, which replace Ti4+ ions in the rutile structure. The rutile unit cell parameters for the V4+-TiO2 solid solutions remained constant up to hi gh temperature (1300 degrees C) and indicated the high temperature sta bility of these solid solutions. Interatomic distances, determined by the Rietveld method, indicated a higher distortion in octahedra of the V4+-TiO2 rutile solid solutions than in rutile TiO2.