Low-temperature relaxation of magnetization in manganite Pr0.4Bi0.3Ca0.3MnO3

Low-temperature relaxation of magnetization in Pr0.4Bi0.3Ca0.3MnO3 ceramics was measured after cooling in a magnetic field and aging at temperatures from 5 K to 38 K near the transition temperature to the magnetically ordered state. It was found that the relaxation process has a thermoactivation character at the first stage and is described in terms of the Arrhenius equation. Its activation energy Q ≈ 1.1 meV is comparable with the antiferromagnetic interaction energy in this compound. The temperature–time dependence of the relaxation rate at the second stage is described by a power law. The relaxation slows down as the temperature approaches the critical value, which may be associated with the formation of a cluster structure in the studied compound under these conditions.