As we know, ZnO exhibits n-type conductivity due to the interstitial diffusion of Zn2+ and 2 electrons in ZnO crystal. My question is whether the n-type conductivity in TiO2 can be attributed to the same phenomenon as the radii of the elements (Ti4+ = 56 pm, neutral Ti = 140 pm, O2- = 124 pm) can support the interstitial diffusion.