Preparation and characteristics of Nb5+, Ta5+/TiO2 nanoscale powders by sol-gel process using TiCl3

Nanoscale TiO2 powders doping with niobium and tantalum were prepared using TiCl3 as a source matter. Characterization of the materials was performed by Thermoanalys, particle size, XRD, BET, FTIR, Magnetic Susceptibility. The influence of niobium and tantalum ions on the phase transition was studied, the changes in the crystal size and microstain distributions obtained at 400° C were analyzed. The results show that the substitutes of Nb5+, Ta5+ for T4+ in the anatase structure cause distortions and improve to form rutile. When the dopant content is over certain molar percent, biphase reappears. The IR spectra and magnetic susceptibility indicate the Nb-Nb (or Ta-Ta) bonds along c-axis in rutile by two Nb5+ (Ta5+) ions located in sites adjacent along the c-axis appear with the dopant content. The magnetic characteristics at rutile showed a weak paramagnetism.