Electrical properties in solid solution Pr1-xSrxMnO3 (0 <= x <= 0.5)

We present the electrical properties of polycrystalline samples Pr1-xSrxMnO 3 (0 less than or equal to x less than or equal to 0.5). These properties a re correlated to the ratio of the Mn3+/Mn4+ cations. The transport properti es of the Pr1-xSrxMnO3 samples could be explained on the basis of double ex change 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 less than or equal to x l ess than or equal to 0.4) with a metallic-like behaviour above a critical t emperature T rho A semiconductor-like one is observed for all the range of temperature (50 to 300 K) for (0 less than or equal to x less than or equal to 0.2 and x = 0.5). Below the Curie temperature T-c, for the ferromagneti c regimes, the spin disorder scattering process has been observed to play a n important role in resistivity behaviour. The evolution of activated energ ies with the: carrier concentration has been investigated.