Structural and Morphological La_0.85-xBa_xNa_0.15MnO₃ (x = 0, 0.05, 0.10 and 0.15) Perovskite Manganite

Abstract

Bulk polycrystalline samples La0.85-xBaxNa0.15MnO3 (x = 0, 0.05, 0.10 and 0.15) manganites were synthesized by the sol-gel route. The effect of Barium (Ba) existence on the structural and morphological was investigated by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The structural parameters were obtained using Rietveld refinement of the XRD pattern. It was revealed the structures of compounds have rhombohedral with R-3c space group without any impurities phase. Furthermore, several changes are found to exist due to Ba substitution such as the lattice parameter, unit cells volume, average crystallite size, average Mn-O bond length (<Mn – O>) and average Mn-O-Mn bond angle (<Mn – O – Mn>). The changes in <Mn – O> and <Mn – O – Mn> due to Ba substitution, affects the double exchange interaction of the samples. SEM images reveal the existence of Ba also affects the morphology of the studied samples, which consisted of polygonal grains with homogeneous chemical composition.