Role of magnetic polarons in ferromagnetic GdN

Abstract

We report an interplay between magnetism and charge transport in the ferromagnetic semiconductor GdN, pointing to the formation of magnetic polarons centered on nitrogen vacancies. The scenario goes some way to resolving a long-standing disagreement between the measured and predicted Curie temperature in GdN. It further constitutes an extension of concepts that relate closely to the behavior of ferromagnetic semiconductors generally, and EuO in particular.