Direct and indirect switch from semiconductor to metallic behavior defined by the competition between Cation–Anion–Cation and Cation–Cation interactions leading to an important technological aspect of perovskite systems

Abstract

We discuss in this work the key interactions that explain the possible electrical behaviors in different perovskite systems. Multi-behavior observation characterizes each frequency and temperature dependence of various perovskite systems. We classify such observations according to the temperature regimes. Indeed, a direct switch from semiconductor to metallic feature describes the conductivity evolution indicating the direct change from the localized (cation–anion–cation interactions) to delocalized (cation–cation interactions) state. The metallic character is reached due to the reinforcement of charge delocalization effect at high temperatures and frequencies. An indirect transformation separated by a frequency-independent regime is equally observed and discussed. Subsequently, a mixed regime is described by the conductivity temperature-independence which is explored at a specific frequency. Such investigations lead to demonstrate basic and common rules relevant for oxide-perovskites multi-behavior. Equally, important technological aspects are confirmed for systems that displays such multi-behavior character according to the temperature range.