The effect of Ge upon the diffusivity of O at 620 to 670K was studied, in dislocation-free [111]-type monocrystals, by using Hall-effect methods. It was found that, in comparison with un-doped monocrystals, the activation energy for O diffusion in Ge-doped material was much closer to the activation energy for O diffusion via the interstitial mechanism.

D.N.Korlyakov: Izvestiya Akademii Nauk SSSR - Neorganicheskie Materialy, 1991, 27[7], 1333-6 (Inorganic Materials, 1991, 27[7], 1129-32)