Influence of different additives on anatase-rutile transformation in titania system

Hydrated titanium oxide gel samples containing 5%, Fe. La, Ce, and Y oxides were prepared. Discs of size 10 mm dia. and similar to1-5 min thickness pressed from dry, precursor gets were heated to temperatures in the range of 400-1000 degreesC at intervals of 200 K for 2 h. The thermal behaviour of the doped rind undoped gels was studied by DTA. The phase changes occurring in the gel precursors were identified using X-ray, diffraction (XRD). The changes in electrical response of doped and undoped samples were monitored at room temperature by impedance spectral measurements. La2O3 was found to be the most effective in increasing the anatase to rutile transformation temperature while Fe2O3 has the reverse effect. Impedance spectroscopy studies reflected the conducting nature of the anatase matrix and the insulating rutile phase and appear to be a simple tool for characterisation of such systems by bulk measurements.