Evolution of microstructure, strain and physical properties of quaternary nanoparticles La 0.8−x Ce x Ag 0.2 MnO 3 perovskites

In this work, the quaternary nanostructure La0.8−xCexAg0.2MnO3 perovskite was synthetized by conventional solid-state method and calcination in air at 900 °C for 24 h. These materials are one member of perovskite-containing manganite, and rare earths and Alkali elements in A and B sites, respectively. The effect of La substitution on the crystallite size and microstrain of the X-ray diffraction (XRD) line broadening is analyzed in different methods. Scanning electron microscope measurements are combined with an energy dispersive X-ray analyzer (EDX) to illustrate the effect of cerium (Ce) atoms adding. Scherrer, Williamson–Hall and size-strain plot methods were used to analyze the line profile of XRD and Rietveld refinement by Fullprof software to determine microstructure parameters of perovskite. The results obtained showed that with the addition of the Ce element, there is no effect on the lattice parameters, which supports the replacement of Ce ions with those of La ion in the unit cell. In addition, the crystal size microstrain and porosity values were systematically decreased with increasing Ce-ion concentrations. The analysis of the surface morphology shows that the process leads to the formation of smaller nanoparticles with two distinguishable size ranges, supporting porosity decrease. These nanoparticles were attributed to pure La0.8−xCexAg0.2MnO3 and the other phases resulting from the interaction of Ce ions. EDX results also indicate that Ce ions have been successfully replaced in La0.8−xCexAg0.2MnO3. Correlation of different results let to conclude that the resulting product can be applied in the future in field of magnetic refrigeration.