Reinspection of formation of BiFe_1-xMn_xO₃ solid solutions via low temperature sol-gel synthesis route

In this study, BiFe_1-xMn_xO₃ (BiFeMnO; x from 0 to 0.5) solid solutions were prepared by low temperature sol-gel processing. It was demonstrated that structural, magnetic and morphological properties of BiFeMnO samples are dependent on the chemical composition of the synthesized BiFe_1-xMn_xO₃ solid solutions. The thermal behaviour of the Bi–Fe–Mn–O precursor gels was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. From X-ray diffraction (XRD) analysis it was observed that monophasic BiFe_1-xMn_xO₃ samples have formed up to 25 mol% of substitution. The Rietveld analysis showed that the structure of BiFeMnO specimens can be indexed by rhombohedral or orthorhombic unit cell depending on Mn³⁺ content. Scanning electron microscopy (SEM) was used to investigate samples morphology and revealed, that smaller particles form when Mn³⁺ is present inside the structure. Moreover, magnetic properties of solid solutions were also investigated, and antiferromagnetism and weak ferromagnetism were observed for the samples.