Effect of La3+ substitution on the structural, electrical and electrochemical properties of strontium ferrite by citrate combustion method

The La3+ substituted nanocrystalline strontium ferrite has been prepared by citrate combustion method using metal nitrate salts as cation precursors and citric acid as a fuel. The structural characteristics of the compounds have been evaluated using XRD and FTIR. The existence of the single-phase perovskite structure with nanocrystalline size has been confirmed from the X-ray powder diffraction patterns. The stretching and bending vibrations of the metal cations are confirmed from the FTIR spectra. The electrical conductivity of the materials is found to increase with increasing temperature measured by using a modified four-probe technique. The electrochemical behavior has been studied by using potentiostatic polarization method in KOH solutions at two different concentrations of 1 and 2 M. From the polarization studies it has been found that the material La0.4Sr0.6FeO3 gives the lowest corrosion rate of 0.001 mmpy in 1 M KOH solution.