The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

Abstract

This investigation is mainly concerned with the effect of annealing temperature (600, 700, 800, and 900 °C) in air for (La₀.₇Ba₀.₃MnO₃)₁–x/(NiO) x with x = 0 and x = 0.10 samples. It was shown that the annealing temperature does not affect the structure and parameters of rhombohedral lattice of the samples. However, it is observed that the annealing treatment has a notable effect on the electrical resistivity and the metal-semiconductor transition temperature Tms. Temperature dependent magnetization measurements showed a decrease in Curie temperature TC with annealing temperature. In the same time, annealing process decreases the magnetoresistance of La₀.₇Ba₀.₃MnO₃, in contrast to (La₀.₇Ba₀.₃MnO₃)₀.₉/(NiO)₀.₁ composite.