Resistive relaxation in the field-induced insulator-metal transition of a (La0.4Pr0.6)1.2Sr1.8Mn2O7 bilayer manganite single crystal

We have investigated the resistive relaxation of a (La0.4Pr0.6)1.2Sr1.8Mn2O7 single crystal, in order to examine the slow dynamics of the field-induced insulator-to-metal transition of bilayered manganites. The temporal profiles observed in remanent resistance follow a stretched exponential function accompanied by a slow relaxation similar to that observed in magnetization and magnetostriction data. We demonstrate that the remanent relaxation in magnetotransport has a close relationship with magnetic relaxation that can be understood in the framework of an effective-medium approximation by assuming that the first-order parameter is proportional to the second-order one.