Electronic and ionic conductivity in CaTiO3

The present work describes the electrical conductivity of undoped CaTiO3 in terms of the electrical conductivity components corresponding to electrons, electron holes and ionic charge carriers in the temperature range 973 K - 1323 K and under controlled oxygen partial pressure (10 Pa - 72 kPa). These data are considered in terms of the transference numbers of the respective charge carriers. It appears that the ionic conductivity component assumes maximum at the n-p transition when the ionic transfer number reaches 50% of the total conductivity value at 1323 K. The present study also includes the determination of the activation energy of the conductivity component related to ions (162.1 kJ/mol), electrons (134.2 kJ/mol) and electron holes (86.2 kJ/mol). The data obtained in this work indicate that undoped CaTiO3 exhibits a substantial level of ionic conduction that cannot be ignored in a quantitative analysis of electrical conductivity data.