Breakdown of the lattice polaron picture in La0.7Ca0.3MnO3 single crystals


When heated through the magnetic transition at TC , La0.7Ca0.3MnO3 changes from a band metal to a polaronic insulator. The Hall constant RH , through its activated behavior and sign anomaly, provides key evidence for polaronic behavior. We use RH and the Hall mobility to demonstrate the breakdown of the polaron phase. Above 1.4TC , the polaron picture holds… (More)