Effect of cerium dopant on the structural and electrical properties of SrMnO3 single perovskite

Abstract

A novel cerium doped strontium manganite (SrMn0.94Ce0.06O3) perovskite is synthesized by means of high-temperature cost effective solid-state reaction technique. A hexagonal crystal structure has been suggested for the above manganite based on their XRD patterns. The average crystallite size of the sample was found to be 72.2 nm using Scherrer's relation. The mechanical lattice strain of 0.181%.is produced in the manganite due to the Ce dopant. The SEM micrograph analysis shows that the grains and grain boundaries are clear and distinctly distributed over the sample and the average grain size of the sample is about 12.5 μm. The role of the grains is predominant over the grain boundaries in conductivity mechanism. Two types of conduction mechanisms justify the dielectric study of the manganite both in the low as well as in the high temperature zone. The calculated activation energy and the shift in the potential confirm that the cerium doped strontium manganite undergoes a thermally activated conducting process. The thermally activated relaxation process is controlled by the possible defects at higher temperatures and the immobile charge carriers at low-temperatures. The presence of symmetrical curve of the electrical modulus plots suggests the Debye-type conductivity behaviour of the modified manganite. The semiconducting nature of the sample is confirmed by both Nyquist and Cole-Cole plots.