Novel synthetic approach to the preparation of single-phase BixLa1−xMnO3+δ solid solutions.

In this study, the Bi_xLa_1−xMnO_3+δ solid solutions (x from 0 to 0.65) were synthesized using sol–gel combustion method with citric acid as a fuel and complexing agent. It was shown that changes in chemical composition of the materials lead to the evolution of crystal structure, morphology, and magnetic properties. The thermal behavior of precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis demonstrated that all samples were monophasic. The Rietveld analysis showed that the structure can be indexed by trigonal or cubic unit cell depending on Bi³⁺ content. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials and revealed that Bi³⁺ ions significantly promote growth of the grains. The sol–gel-derived Bi_xLa_1−xMnO_3+δ specimens were also characterized by FT-IR spectroscopy and magnetization measurements, which showed a clear correlation between magnetic properties and crystal structure of the materials. Highlights: Bi_xLa_1–xMnO_3+δ solid solutions (x from 0 to 0.65) were synthesized by the sol–gel combustion method. The suggested synthetic approach does not require addition of external solvent. Structural, morphological and magnetic properties depend on the chemical composition of compounds. [ABSTRACT FROM AUTHOR]