Electrical transport properties of Pr_1−xSr_xMnO₃(x= 0 to 0·45)

Abstract

The electrical transport properties of polycrystalline Pr 12x Sr x MnO 3 (x50 to 0?45) perovskite manganites prepared by the solid state reaction method have been studied. The insulator-metal transition temperature T im shifted to higher temperatures when Sr content was increased. Generally, the average grain size decreased with increase in Sr content. The resistivity versus temperature curves in the metallic (ferromagnetic) and insulating (paramagnetic) region were fitted with several models. The activation energy of electrons hopping and the density of states at the Fermi level were estimated from the curve fitting. The r-T 2 curve was found to be nearly linear in the metallic region, but the r-T 2?5 curve deviated from linearity for x50?2 and 0?33. The variable range hopping model and small polaron hopping models fit well in the high temperature region. Sr substitution led to the decrease in the activation energy and the T o values.

Study of complex impedance spectroscopic properties of La 0.7− x Dy x Sr 0.3 MnO 3 perovskite oxides

“…The values of activation energy estimated from the Arrhenius plot of s dc for LSMO and LDSMO with respect to 1000/T are 0.210(6) eV and 0.535(7) eV, respectively. These values are higher than those obtained for other manganites, as shown in table 4 [15][16][17].…”