Influence of heat treatment on the vacancy content at the B‐site in the ABO3 manganites La0.6Sr0.1MnO3−δ

Abstract

AbstractThe effects of heat‐treatment temperature, THT, and heat‐treatment time, tHT, on the structural and magnetic properties of manganites with a nominal composition La0.6Sr0.1MnO3−δ, prepared by the sol–gel method, were investigated. The XRD spectra indicate that the samples have two phases with the $R\overline {3} c$ perovskite being the dominant phase and Mn3O4 being the second phase. It was found that the Curie temperature of the samples varies as THT and tHT are changed. Calculation of the ion content ratios at the A, B, and O sites in the ABO3 perovskite phase on the basis of the thermal equilibrium theory of crystal defects, and Rietveld fitting of X‐ray powder diffraction data lead us to believe that the origin of this variation is due to the fact that the vacancy content, z, at B‐sites in the ABO3 perovskite phase increases as THT and tHT increase. The calculations also show that the samples are double‐phase compositions of La0.6Sr0.1Mn1−yO1.5(1.7‐y+z)/(Mn3O4)y/3.