The effect of the temperature and O partial pressure upon the electrical conductivity of pure, Li- or Ti-doped material was investigated at 873 to 1173K. The pure and Li-doped MgO always exhibited p-type conductivity in this temperature range, whereas Ti-doped MgO always exhibited n-type conductivity. Defect chemistry equations were used to describe the formation of lattice defects. It was proved that Li doping increased the concentration of O vacancies, and hence p-type conduction, whereas Ti doping suppressed the formation of O vacancies. Properties such as catalysis were explained in terms of defect chemistry concepts.

Specific Defect Sites Creation by Doping MgO with Lithium and Titanium. I.Balint, K.Aika: Applied Surface Science, 2001, 173[3-4], 296-306