Anomalous Hall effect in epitaxial ferrimagnetic anti-perovskite Mn_4−xDy_xN films

Anomalous Hall effect (AHE) has been studied for ferrimagnetic antiperovskite Mn_4−xDy_xN films grown by molecular-beam epitaxy. The introduction of Dy changes the AHE dramatically, even changes its sign, while the variations in magnetization are negligible. Two sign reversals of the AHE (negative-positive-negative) are ascribed to the variation of charge carriers as a result of Fermi surface reconstruction. We further demonstrate that the AHE current J_AH is dissipationless (independent of the scattering rate), by confirming that anomalous Hall conductivity, σ_AH, is proportional to the carrier density n at 5 K. Our study may provide a route to further utilize antiperovskite manganese nitrides in spintronics