Electron transport in CaMnO3 - δ at elevated temperatures: A mobility analysis

Abstract

The drift mobility of electron charge carriers in oxygen non-stoichiometric manganite CaMnO3 - δ was calculated by combining the total electrical conductivity and oxygen non-stoichiometry data at 700-950 ° C and oxygen partial pressure varying between 10-6 and 1 atm. The carrier concentration changes with pressure and temperature were obtained with the help of the earlier-developed defect model involving reactions of oxygen exchange and thermal excitation of manganese sites. The activation energy for mobility is found to increase with oxygen non-stoichiometry. High-temperature electron transport properties of the manganite CaMnO3 - δ can be explained in terms of activated jumps of n-type small polarons in adiabatic regime. The relatively small mobility of charge carriers is explained by strong localization of polarons on manganese sites. © 2013 Springer-Verlag Berlin Heidelberg.