SYNTHESIS OF PEROVSKITE TYPE MIXED OXIDES OF LANTHANE AND IRON La1-X SrXFeO3 BY CITRATE METHOD

Abstract

The study, preparation and evaluation of mixed metal oxides are receiving great attention given the benefits of these solids, including the innovation of new materials. In this research work, perovskite-type mixed oxides with the structural formula La1-xSrxFeO3 were prepared, varying the amount of strontium from 0 to 0.5 (x = 0; 0.1; 0.4 and 0 ,5) by the citrate method. The solids obtained were analyzed by the following characterization techniques: X-ray diffraction (XRD), energy dispersive X-rays (EDX) and transmission electron microscopy (TEM). When analyzing the solids by XRD, it was observed that the materials are homogeneous with high crystallinity and purity, a phase corresponding to the perovskite type and a stable structure without the presence of amorphous particles. The results obtained by EDX presented slight variations with the theoretical values, which may be due to the fact that the analysis is semiquantitative, despite this, the solids obtained show the incorporation of Sr in the crystalline lattice of LaFeO3 with very few impurities. In the TEM analysis it was determined that in the particles La0,9Sr0,1FeO3, La0,6Sr0,4FeO3  y La0,5Sr0,5FeO3, nanometric solids with sizes ranging from 7 to 50 nm were obtained, corroborating the heterogeneity with respect to size.