Determine the sign of interfacial DMI in thin films

Determine the sign of the interfacial Dzyaloshinskii–Moriya interaction at the CoB/Ir interface in thin-film multilayers, thereby establishing whether the interface contributes an increase or decrease to the net iDMI effect.

Background

The paper proposes that hybridisation at the C₆₀/Ir interface enhances spin–orbit coupling in Ir and modifies the iDMI at the CoB/Ir interface. Because the multilayer contains strongly ferromagnetically coupled [Pt/CoB/Ir] repeats, this interfacial modification is inferred to affect the effective iDMI and magnetic domain structure throughout the stack.

However, the authors state that the actual change in the CoB/Ir interfacial contribution depends on the sign of the iDMI at that interface. They identify determining this sign as an established open question in thin-film iDMI research and explain that their measurements cannot directly determine or infer it.

References

It should be noted that the mechanism is limited to discussions of the net iDMI effect across the top [Pt/CoB/Ir] repeated unit. The actual strength in terms of an increase/decrease of the iDMI contribution at the CoB/Ir interface will depend entirely on the sign of iDMI at that particular interface. This is a well known open question in iDMI research in the context of thin films and the iDMI sign cannot be directly determined nor inferred from the work presented here.

— Indirect Control of Buried CoB Spin Textures via C$_{60}$-Induced Modification of Ir Spin-Orbit Coupling  (2610.21704 - Kirkbride et al., 15 Oct 2026) in Discussion section, paragraph beginning “We hypothesise that the nature of the C₆₀ hybridisation”