Phase separation region in the phase diagram of polycrystalline Pr0.65Ca0.35−xSrxMnO3

Abstract We have performed measurements of thermoelectric power, electrical resistivity and DC magnetization in polycrystalline samples of Pr 0.65 Ca 0.35− x Sr x MnO 3 with x =0, 0.02, 0.05, 0.10 and 0.20. The system presents an evolution from a charge-ordered manganite at x =0, with an insulating-like resistivity and low magnetization values, towards a ferromagnetic (FM) metallic state for x =0.20. We show that in the intermediate region a strong competition between the FM double-exchange and the localized charge-ordering occurs, inducing the phase segregation of the two competing states in a wide temperature range. We estimate the temperature ( T ) evolution of the FM phase fraction of the x =0.10 sample and construct a complete T − x phase diagram.