Interplay between magnetism and charge transport in antiperovskite manganese nitrides: Extremely low temperature coefficient of resistance due to strong magnetic scattering

Abstract

The recently discovered low temperature coefficient of resistance (low TCR) in Mn3Ag1-xCuxN exemplifies the peculiar magnetic and electronic states of this class of manganites. Despite its overall metallic character, a broad maximum appears in the temperature–resistivity curve in the paramagnetic region, and extremely low TCR is achieved over a temperature window that includes room temperature. The peak temperature can be tuned via Cu content x. It is apparently related to the magnetic transition temperature. These peculiar behaviors are possibly a result of the collapse of coherent quasiparticle states by strong magnetic scattering. We discuss the interplay between magnetism and charge transport in terms of magnetoresistance.