EFFECT OF PRASEODYMIUM SUBSTITUTED ON THE STRUCTURAL AND ELECTRICAL TRANSPORT PROPERTIES OF La0.5Ba0.5MnO3 PEROVSKITE

Abstract

The influence of praseodymium substituting at La-site in La_0.5Ba_0.5MnO₃ has been investigated, in magnetotransport and structural properties. The doping Pr at La site on La-Ba-Mn-O ceramics was using solid state reaction. Polycrystalline (La_1-x Pr_x)_0.5Ba_0.5MnO₃ (x = 0, 0.167, 0.33, 0.5, 0.67, 0.833, 1) is doped with Pr site based manganites, calcined at 900^oC for 12 hours, pelletized and sintered at 1300^oC for 24 hours have been synthesized and investigated. The electrical property, T_p was determined by using standard four-point probe resistivity measurement in a temperature range of 30 K to 300 K. With increasing the Pr doping, T_p for the films shifted to lower temperatures, which are 254, 248, 228, 220, 196, 180, 158 K for the bulks with x = 0, 0.167, 0.33, 0.5, 0.67, 0.833, 1, respectively. As the Praseodymium concentration increases, the metal-insulator transition temperature (T_p) decreases while the activation energy in the insulating region (T > T_p) and resistivity increases. The structural property of bulk samples have been investigated via X-Ray Diffragtometer (XRD). XRD patterns show that these systems are in single-phase. The lattice parameters of undoped sample, La_0.5Ba_0.5MnO₃ can be observed at, a  15.120 Å, b  7.776Å and c  4.335Å. All the samples are in orthorhombic distortion perovskite structure with a > b > c. The unit cell volume decreases as Pr concentration increases.