Near-Room-Temperature Valence Transition in a Strain-Tuned Perovskite
Oxide
Near-Room-Temperature Valence Transition in a Strain-Tuned Perovskite
Oxide
Cobalt oxides have long been understood to display intriguing phenomena known as spin-state crossovers, where the cobalt ion spin changes vs. temperature, pressure, etc. A very different situation was recently uncovered in some praseodymium-containing cobalt oxides, where a first-order coupled spin-state/structural/metal-insulator transition occurs, driven by a remarkable praseodymium valence transition. …