Study of the Effect of Synthesis Method on Obtaining Ca0.3La0.7MnO3

It is known that magnetic, electric and optical properties of materials from mixed oxides mainly depend on the synthesis method used, therefore it is important to perform studies about the use of several synthesis routes with the purpose to understand and control the obtention of any given phase. In many of these routes it is required to control parameters such as temperature, pH, the variation of dopant concentration, etc. By this reason, in this work the effect of the method for three different synthesis routes (chemical coprecipitation, mechanosynthesis and combustion) was studied. These methods were used in the obtention of calcium manganite doped with lanthanum of theoretical stoichiometric Ca0.3La0.7MnO3, using metallic minerals like precursors. The obtained powders were analyzed and characterized by X-ray diffraction (XRD), particle size analysis (PSA), scanning electron microscopy (SEM) and electron paramagnetic resonance (EPR). The crystallographic study (XRD) showed the obtention of calcium manganite doped with lanthanum with orthorrombic type structure, observed by SEM, agglomerates formed by particles with sizes smaller to one micrometer. By EPR it was found that powders obtained by chemical coprecipitation method showed magnetic behavior, in contrast with the behavior obtained by other two methods used, finding also powders with greater purity and in shorter synthesis time with regards to the ones obtained by mechanosynthesis and combustion.