Effect of Ni-doping on the structural, magnetic, and electronic properties of La0.2Sr0.8MnO3 perovskite

The effect of light Ni-substituted Manganese on the physical properties of La0.2Sr0.8MnO3 perovskite prepared by the standard solid-state reaction method was investigated. Field Emission Scanning Electron microscopy confirms the particle size composition and grain boundaries in these samples. Moreover, the presence of all the chemical elements with atomic ratios coordinating with the general formula La0.2Sr0.8Mn1-xNixO3 (x = 0.0 and 0.1) was confirmed by Energy-dispersive X-ray spectroscopy. X-ray diffractions analyses indicate that both compounds have a rhombohedral structure with an R3C space group, for which the cell parameter increases with nickel addition. A competition between ferromagnetic and antiferromagnetic moments is evidenced at room temperature for both compounds by measuring the magnetization versus magnetic field. Saturation magnetization and the corresponding residual magnetization decrease with the Ni substitution; however, the coercive field increases. These changes are correlated with those evidenced by structural properties. Conductance measurements as a function of frequency from 10(2) Hz to 5 MHz are analyzed in the temperature range 300 K-420 K in order to evidence the conduction mechanism.