Solid solutions of La-doped BiFeO3 obtained by the Pechini method with improvement in their properties

Abstract

In this work, the synthesis of a series of solid solutions of Bi1−xLaxFeO3 (BLFO) (0≤x≤ 0.15) obtained by the Pechini method is reported. The effects of lanthanum concentrations on the phase formation, grain size, as well as electric and magnetic properties were studied. The XRD results displayed the single BiFeO3 (BFO) phase for the different employed compositions. Crystal structure and cell parameters were refined by the Rietveld analysis, indicating that the obtained ceramics crystallized in the rhombohedral structure. The slight variation of the cell parameters and density values confirmed the partial substitution of Bi3+ by La3+ into the perovskite A site like BiFeO3 structure. Scanning electron microscopy was used to obtain the morphology of the different synthesized compounds, revealing a diminution of the grain sizes during the sintering process, attributed to the increment of La3+ content. Electric impedance spectroscopy (EIS) measurements were performed to evaluate the electric properties, thus showing a notable increase in the permittivity. The effect of incorporating lanthanum into the BFO structure enhanced ferroelectric and ferromagnetic properties.