Electrical measurements on molten TiO2 using a floating zone furnace

The electrical properties of high-temperature TiO 2 melts were evaluated using a modified floating zone furnace with four ellipsoidal mirrors and Ir electrodes. A droplet of molten TiO 2 was suspended with two Ir electrodes. The resistivity of the molten TiO 2 decreased in the reducing atmosphere, and with Ta 2 O 5 doping. Thermoelectric power, up to 250 mV, due to the temperature difference at the electrodes, was observed in the specimens with and without Ta 2 O 5 doping in Ar and/or 20% O 2 -Ar atmospheres. The thermoelectric power of Ta 2 O 5 -doped TiO 2 is slightly larger than that of non-doped TiO 2 . This phenomenon is discussed based on the Seebeck effect, the diffusion potential and/or the electrochemical potential.