Abstract: The dependence of the electrical conduction of Mg-doped SrTiO₃ ceramics on the temperature and the oxygen partial
pressure was discussed. The Mg contents in SrTiO₃ were taken as 10mol%(sample 1), 20mol%(sample 2), 30mol%(sample 3), 40mol%(sample 4) and 50mol%(sample 5), respectively. All samples were
measured in the temperature range 20～900℃ and P_O2 region from 3.8×10^-4 to 1.2×10^-1 atm. The results show that all samples
exhibit p-type semiconduction. The factor m from R∝ P_O2^-1/m is dependent on temperature and Mg content in SrTiO₃. The obtained results
can be appropriately explained according to the X-ray diffraction patterns and the theory of defect chemistry.

Key words: SrTiO₃ ceramic, defect chemistry, nonstoichiometry, electrical conductivity