Resistivity Anomaly in Doped Barium Titanate

Abstract

The barrier‐layer model previously proposed to explain the anomalous increase in resistivity that occurs in doped BaTiO 3 has been reexamined in the light of data obtained from more recent experiments. The picture thus obtained describes correctly and quantitatively the resistivity anomaly and the frequency and voltage dependence of the resistivity in the entire temperature range investigated (‐180° to +200°C). The activation energy of the donors and of the surface states as well as the density of states in BaTiO 3 were determined and are in close agreement with other investigations. Comments are made regarding the uncertainty of the nature of the surface states.