Resistive relaxation in the field-induced insulator-metal transition of a (La_(0.4)Pr_(0.6))_(1.2)Sr_(1.8)Mn_2O_7 bilayer manganite single crystal

摘要

We have investigated the resistive relaxation of a (La_(0.4)Pr_(0.6))_(1.2)Sr_(1.8)Mn_2O_7 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.