Magnetic and Transport Properties of Ln_(0.5)Sr_(0.5)MnO_(3-delta) (Ln(velence)Pr, Nd) Single Crystals: Dependence on Oxygen Content

摘要

The magnetic and transport properties of Ln_(0.5)Sr_(0.5)MnO_(3-delta) (Ln(velence)Pr, Nd) single crystals have been studied as a function of oxygen content. The (delta)(velence)0 sample exhibits successively a ferromagnetic-metallic phase transition and a charge/orbital-ordered antiferromagnetic-insulating phase transition. On the other hand, the oxygen deficient sample exhibits a spin-glass-like behavior. These results could be attributed to the influence on the ferromagnetic double exchange and antiferromagnetic superexchange interactions by the change of oxygen content and Mn valency.