Impact of Dzyaloshinskii-Moriya interactions on the thermal stability factor of heavy metal/magnetic metal/oxide based nano-pillars

We studied the thermal stability of ultrathin perpendicular magnetized nanodots in the presence of the Dzyaloshinskii-Moriya interaction (DMI) using a minimum energy path method. We find that the smallest energy barrier is associated with the energy path based on domain wall nucleation and propagation down to 25 nm lateral size. We show that the DMI has a detrimental impact on the thermal stability factor of square Pt/Co/AlO x dots, which decreases linearly with the DMI amplitude. Our study reveals that the DMI limits the downscaling of MRAM cells based on heavy metal/ferromagnet/oxide trilayers.