Influence of NaCl on the formation of stoichiometric polycrystalline La0.85Na0.15MnO3

Abstract

Origination of defects and loss of Na during the sintering process are the major problems for the conventional solid-state synthesis technique to form sodium (Na) doped lanthanum manganite. To minimize defect and Na loss during the sintering process, the sodium (Na) doped lanthanum manganite with 15% substitution of La by Na (La_0.85Na_0.15MnO₃) was synthesized using the NaCl flux material incorporated with the conventional solid-state reaction technique (flux method). The amount of micro strain, lattice strain and dislocation density for the flux method to grow polycrystalline La_0.85Na_0.15MnO₃were detected successfully. The structural study using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Analysis X-Ray (EDAX) showed that the use of flux synthesis technique instead of conventional solid-state reaction technique was satisfactory to obtain stoichiometric La_0.85Na_0.15MnO₃ polycrystalline structure with a smaller defect. From the closer inspection of the XRD spectrum for La_0.85Na_0.15MnO₃ significantly showed a higher order layered structure for the cathode material for using this flux technique, which is a very important feature to increase the efficiency of the cathode material.

Bangladesh J. Sci. Ind. Res.54(4), 289-296, 2019