Effect of Fe-doping on the structural, morphological and electrical properties of LaMnO3

Nanosized particles of Fe doped LaMnO3 (at different concentration: 0.05; 0.01; 0.15 %) were obtained by sol-gel technique, followed by heat treatment at low temperature. The effect of dopant concentration on the structural, morphological and electrical properties was studied. The as-obtained materials was characterized by X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), and Ultraviolet-Visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX). Also, the electrical conductivity of the samples was determined in the 100 Hz to 2 MHz frequency range, at room temperature. The XRD results indicated that the obtained materials are characteristic of well crystallized samples with orthorhombic structure (Pnma space group) and the average crystallite size approximately 44 nm. The elemental analysis showed the purity of the obtained materials, and the quantification confirmed the stoichiometry of the compounds (ABO3). The frequency dependence of the electrical conductivity σ of the samples was determined, and they follow Jonscher's law. The electrical conductivity spectrum is formed by both the static component σDC corresponding to the low frequencies and the component σAC corresponding to high frequencies. The results show that in the low frequency range (below 1 kHz), the σDC values LaMnO3 materials are not influenced by the Fe doping concentration.