Effect of Sr-substitution on the structural and dielectric properties of LaFeO3 perovskite materials

Abstract

The study aims to investigate the structural and dielectric properties of perovskite La[Formula: see text]SrxFeO3 ([Formula: see text] = 0.1, 0.2, 0.3, and 0.4) synthesized by sol–gel and sintering methods. X-ray diffraction (XRD), transmission electron microscopy (TEM), and LCR-Meter were used to identify the phase, crystallography parameters, morphology, particle size, and electrical behavior of the synthesized perovskite materials. The samples showed a single-phase orthorhombic crystal structure with Pbnm space group. Sr-substitution induced the volume unit cell and crystallite size to decrease. The synthesized nanoparticles were uniform and homogeneous with the particle size less than 200[Formula: see text]nm. Impedance spectroscopy (IS) was used to explain the electrical behavior as a function of frequency (100[Formula: see text]Hz to 1[Formula: see text]MHz) at various temperatures (300–373[Formula: see text]K). The presence of small polarons as charge carriers within the grain and grain boundary were elucidated from the electrical conductivity experiments. Sr-substitution caused the dielectric constant and electronic conductivity to increase with the highest values obtained from La[Formula: see text]SrxFeO3 ([Formula: see text]).