Electrical conductivity and carrier mobility in Ca1–x Pr x MnO3–δ manganites

The electrical conductivity (σ) of Ca1–xPrxMnO3–δ (х = 0–0.15) manganites with a perovskite-like structure has been measured by the four probe method in air at temperatures (T) from 320 to 1220 K. The results have been analyzed in terms of a model of small adiabatic polarons. The observed decrease in σ with increasing T is primarily due to the decrease in carrier concentration as a result of Mn3+ disproportionation into Mn2+ and Mn4+. The polaron mobility ranges from 0.2 to 1.2 cm2/(V s) and decreases with increasing praseodymium content.