The exchange bias effect in a compensated ${\mathrm{IrMn}}_3/\mathrm{Co}(111)$ system is studied using multiscale modeling from ab initio to atomistic spin model calculations. We evaluate numerically the out-of-plane hysteresis loops of the bilayer for different thicknesses of the ferromagnetic layer. The results show the existence of a perpendicular exchange bias and an enhancement of the coercivity of the system. To identify the origin of the exchange bias, we analyze the hysteresis loops of a selected bilayer by tuning the different contributions to the exchange interaction across the interface. Our results indicate that the exchange bias is primarily induced by Dzyaloshinskii-Moriya interactions, while the coercivity is increased mainly due to a spin-flop mechanism.

• Received 8 April 2013

DOI:https://doi.org/10.1103/PhysRevLett.111.217202