Dynamic behavior of resistivity irreversibility induced by thermal cycling in perovskite charge ordering manganites

The mechanism behind resistivity irreversibility triggered by thermal cycling in perovskite charge-ordering manganites has yet to be unraveled, largely due to the absence of a coherent explanation. The application of a low-temperature electron-paramagnetic-resonance (EPR) spectroscopy technique is essential to distinguish between ferromagnetic and antiferromagnetic distributions. Here, we experimentally show that the fraction of the ferromagnetic phase in Nd_0.5Ca_0.5MnO₃ induced by slight Cr-substitution diminishes with the increase of thermal cycling frequency, as observed via EPR. The thermal cycling process accelerates the relaxation of the interfacial stress between the ferromagnetic and antiferromagnetic regions, leading to a scenario where the Coulomb interaction among Cr ions dispersed across the interface exceeds the attractive force of the local ferromagnetic clusters. This results in an amplified charge-ordered antiferromagnetic phase and the emergence of resistivity irreversibility. Moreover, this compound exhibits an exceptionally high temperature coefficient of resistance (approximately 30%), which is the largest magnitude in the perovskite manganite family. Our research not only sheds light on the mechanism behind the unusual resistivity irreversibility but also paves the way for the advancement of oxide-based infrared detection technology.