Electrical Properties in Solid Solution Pr1?xSrxMnO3 (0 ? x ? 0.5)

Abstract

We present the electrical properties of polycrystalline samples Pr1—xSrxMnO3 (0 ≤ x ≤ 0.5). These properties are correlated to the ratio of the Mn3+/Mn4+ cations. The transport properties of the Pr1—xSrxMnO3 samples could be explained on the basis of double exchange mechanism between pairs of Mn3+ and Mn4+ cations, with conductivity occurring by electron hopping between manganese ions along Mn–O–Mn bonds. A semiconductor-to-metal transition is observed as a function of temperature for the mixed valence samples Pr1—xSrxMnO3 (0.25 ≤ x ≤ 0.4) with a metallic-like behaviour above a critical temperature Tϱ. A semiconductor-like one is observed for all the range of temperature (50 to 300 K) for (0 ≤ x ≤ 0.2 and x= 0.5). Below the Curie temperature Tc, for the ferromagnetic regimes, the spin disorder scattering process has been observed to play an important role in resistivity behaviour. The evolution of activated energies with the carrier concentration has been investigated.