Electrical conductivity measurements were used to study the diffusion of defects in rutile at 300 to 800C. It was deduced that the activation energy for O vacancy diffusion was 0.84eV.

Defect Diffusion in Rutile Partly Reduced in Vacuum. Barbanel, V.I., Bogomolov, V.N.: Fizika Tverdogo Tela, 1969, 16[9], 2671-2