摘要
Superionic transition(SIT)is an extraordinary phenomenon where a compound attains high ionic conductivity through anomalous disordering of mobile-ion sublattice.Comprehending SIT offers notable prospects for the advancement of superionic conductors(SICs)for diverse applications.However,the investigation of SIT is impeded by its intricate and stochastic characteristics,coupled with the absence of adequate methods for characterizing,quantifying,and analyzing its microscopic properties.Here we show that the SIT can be discerned through the dynamic signatures of disordering events underlying the increase in ionic conductivity.The adoption of a dynamic perspective as opposed to the conventional treatment of equilibrium properties brings significant advantage to scrutinize the microscopic characteristics of SIT.Our results show the SIT in the prototypical family of fluorite compounds is characterized by the scaleinvariant disordering dynamics independent of temperature or extent of disorder.The observation of scale-invariance in the absence of external tuning implies that the superionic conduction is self-tuned to criticality by intrinsic dynamics.The connection between ionic diffusion and self-organized criticality provides a novel platform for understanding,analyzing,and manipulating SIT towards better SICs.
