Scientists at EPFL and the University of Geneva have combined two powerful, cutting-edge techniques to uncover the physics behind an exotic phase transition that turns a metal into an insulator. The materials they looked at are rare-earth nickelates, which are of great interest for innovating new approaches in electronics.
“Phase transitions” are a central phenomenon in physical sciences. Despite being technical-sounding, they are actually something we all experience in everyday life: ice melting into liquid water, or hot water evaporating as steam. Solid, liquid, and gas are three well known “phases” and, when one turns into another, that is a phase transition.
Rare-earth nickelate oxides, also called nickelates, have attracted a lot of interest from researchers because they display an electronic phase transition, which may be exploited in future electronic devices. This particular phase transition consists of turning from a metallic state that conducts electricity into an electrically-insulating state as temperature drops.
Source: “Nano-mapping phase transitions in electronic materials”, Nik Papageorgiou, EPFL News