It was shown that, when a small amount of O was dissolved in monocrystals at 1700 to 2050K, the O mobility and its activation energy had comparable values to those for C vacancies. It was suggested that, within this temperature range, O diffused via C vacancies.

Oxygen Diffusion in TiC at High Temperatures. E.M.Fryt: Solid State Phenomena, 2000, 72, 63-8