Electrical Resistivity and Defect Energy Levels in Reduced Titanium Dioxide at Low Temperatures

The resistivity of reduced rutile was measured from 80°K down to about 2°K. Activation energies derived from the slopes of resistivity curve are 0.01∼0.02 eV above about 20°K and 0.0005∼0.005 eV below about 20°K. It is proposed that the electronic conduction in this substance below about 20°K is due to the “defect level conduction” Conduction mechanisms at higher temperatures are also discussed.