Study of the effect of synthesis method on obtaining Ca0.3la0.7MnO3
Por:
Hernández L.E.C., Montiel M.H.S., Guillermo A.L., Legorreta F.G., Bolarín A.M.M., Sánchez de Jesús F.
Publicada:
1 ene 2014
Categoría:
Engineering (miscellaneous)
Resumen:
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 of understanding and controling the obtainment of any given phase. In many of these routes, it is required to control parameters such as temperature, pH, variation of dopant concentration, etc. For this reasoning, in this work, three different synthesis routes (chemical coprecipitation, mechanosynthesis, and combustion) were studied to determine the effect. These methods were used to obtain calcium manganite doped with lanthanum of theoretical stoichiometric Ca0.3La0.7MnO3, using metallic minerals as 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 obtainment of calcium manganite doped with lanthanum with an orthorhombic type structure. Observed by SEM, agglomerates were formed by particles with sizes smaller than one micrometer. By EPR, it was found that powders obtained by the chemical coprecipitation method showed magnetic behavior, contrasting to the behaviors obtained by the other two methods used. With EPR, powders with greater purity were also found and were obtained in a shorter synthesis time than those obtained by mechanosynthesis and combustion.orthorhombic type structure. Observed by SEM, agglomerates were formed by particles with sizes smaller than one micrometer. By EPR, it was found that powders obtained by the chemical coprecipitation method showed magnetic behavior, contrasting to the behaviors obtained by the other two methods used. With EPR, powders with greater purity were also found and were obtained in a shorter synthesis time than those obtained by mechanosynthesis and combustion. © (2014) Trans Tech Publications, Switzerland.
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