Magnetic and transport behaviors of Co substitution in La0.7Sr0.3MnO3 perovskite

The magnetic and electrical properties of the substituted La0.7Sr0.3Mn1-xCoxO3 perovskite (0 <= x <= 1) were studied. Analysis of the average spin value obtained from inverse magnetic susceptibility using Curie-Weiss law for the samples suggested Co4+ ions were in the high spin state, whereas the spin state of Co3+ ions transformed from high spin to intermediate-spin state at x= 0.8. The metallic conduction behavior of the x = 0 and x = 1 samples was analyzed using the empirical equation rho(t) = rho(0) + rho T-2(2) + rho T-4.5(4.5), reflecting the importance of electron-magnon scattering effects similarly to other manganites. All the other samples displayed semiconductor-like behavior throughout the studied temperature range. The resistivity data in semiconducting La0.7Sr0.3Mn1-xCoxO3 could be fitted to the model of variable range hopping, and both hopping distance and average hopping energy reduced with increasing doped Co concentration. (C) 2022 Elsevier B.V. All rights reserved.