Correlation between magnetic and electrical properties of the superparamagnetic La0.6Ca0.4MnO3 compound

In this research work, we investigated the correlation between the electrical and magnetic properties of the superparamagnetic compound La _0.6Ca _0.4MnO ₃ ( S 0 C 1 ) prepared by the citric-gel method. The confrontation of the experimental data with the theoretical models revealed that the conduction at low temperatures, in the ferromagnetic metallic ( F M M ) phase, can be mainly described by electron–electron ( e - e ) and electron-magnon ( e - m ) interactions. The contribution of the ( e - m ) interaction, became weak for strong magnetic fields. At high temperatures, in the paramagnetic semiconductor ( P M S C ) phase, the thermally activated hopping ( T A H ) model proved to be the most appropriate to fit the experimental data. To describe the resistivity behavior in a wide temperature range including the phase transition region between the ( F M M ) and ( P M S C ) phases, we adopted the percolation model, based on the phase segregation mechanism.