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 , 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.