The organic residue and synthesis of LaFeO3 by combustion of citrate and nitrate precursors

Abstract

Perovskite type LaFeO3 has been synthesized by autocombustion of the gel complex obtained from citrate and metal nitrate precursors. The crystallinity in the as-combusted powder and effects of heat treatment temperature up to 800 °C have been investigated by XRD. Thermal stability of the organic residue obtained after combustion has been studied by TGA of as-combusted powder and FTIR analysis after heat treatment at different temperatures. In addition to the crystalline LaFeO3, amorphous organic residue was found in the as-combusted powder that gradually decomposed upon heat treatment. Effects of the amorphous organic residue on the dielectric properties of LaFeO3 has been explored and discussed in details by collecting the room temperature ac impedance data in a wide frequency range for the synthesized samples. The amorphous organic residue strongly alter the resistive and dielectric properties of LaFeO3. The frequency response of the dielectric polarization is associated with the dielectric relaxations from the amorphous residual carbonates, crystalline LaFeO3 grain interiors and the grain boundaries.