Phase separation in La-Pr manganites and its evolution in a magnetic field

Abstract

The effect of the magnetic field H on the electrical resistivity ρ and magnetic moment M of (La0.25Pr0.75)0.7Ca0.3MnO3 ceramic samples with various concentrations of 16O and 18O isotopes is studied. The behavior of ρ(H) and M(H) is characterized by an unusual shifted hysteresis loop and slow relaxation at some of its sections. The effects observed are interpreted within the framework of a model that takes into account the coexistence of regions of a ferromagnetic metal and an antiferromagnetic insulator and their evolution in an external magnetic field.