Structural, morphological and magnetic properties of La1−xNayMnO3(y ≤ x) nanoparticles produced by the solution combustion method

摘要

The rapid solution combustion synthesis and characterization of sodium (Na)-substituted LaMnO3udphases at relatively low temperature using polyvinyl alcohol (PVA) as fuel were reported. The thermal decomposition process investigated by means of differential and thermal gravimetric analysis (TG–DTA) showed that the use of PVA as a fuel was satisfactory in the synthesis of the perovskite manganite compound. Structural study using X-ray diffraction showed that all the samples were single phasic without any detectable impurities within the measurementudrange. Also, the Na-substituted compounds crystallize with rhombohedral symmetry (space group R-3c, no.ud167) with La0.80Na0.15MnO3 manganite sample giving the highest crystallinity. Microstructural features observedudby field-emission scanning electron microscopy demonstrated that most of the grains were nearly spherical in shapeudwith fairly uniform distribution and all the observed particles connect with each other. Energy-dispersive X-rayudanalyses confirm the homogeneity of the samples. Increase in magnetic moment was observed with the increase inudsodium doping. Room-temperature vibrating sample magnetometer measurements showed that the samples wereudferromagnetic with compositions y=0.10, 0.15 and 0.20 showing relatively high magnetic moments of 33, 34 and 36udemu g−1, respectively.udKeywords. Na-doped lanthanum manganites; solution combustion method; nanoparticles; magnetism.