An empirical model for magnetic field dependent resistivity and magnetoresistance in manganites: application on polycrystalline charge-ordered La0.4Gd0.1Ca0.5MnO3.

In this paper, we have investigated the electrical and magnetic response of a La0.4Gd0.1Ca0.5MnO3 polycrystalline sample. This sample seems to exhibit fascinating phenomena like charge ordering, magnetic phase separation, training effects and kinetic arrest. It also shows colossal values of negative magnetoresistance (∼91.7% at 96 K under 1 T applied magnetic field), which raises the possibility of using this sample for technological applications. We have also proposed, in this work, a new empirical model to describe the evolution of resistivity and magnetoresistance as a function of magnetic field. This model was successfully tested on the La0.4Gd0.1Ca0.5MnO3 sample in spite of its complicated magnetic behavior, which suggests the use of this model for other magnetic samples in order to check its validity.