Defect-driven extreme magnetoresistance in an I-Mn-V semiconductor.

The search for appropriate materials for technological applications is challenging, as real materials are subject to uncontrolled doping and thermal effects. Tetragonal NaMnBi of the I-Mn-V class of antiferromagnetic semiconductors with a Néel transition (), above room temperature, can exhibit an extreme magnetoresistance (MR), greater than 10000% at 2K and 600% at room temperature and 9T by quenching disorder into the system. Coupled with the large MR is a re-orientation of the magnetic moment, from a collinear spin arrangement along c to a canted one along the (011) crystallographic axis.