Full electrical manipulation of perpendicular exchange bias in ultrathin antiferromagnetic film with epitaxial strain.

Achieving effective manipulation of perpendicular exchange bias effect remains an intricate endeavor, yet it stands a significance for the evolution of ultra-high capacity and energy-efficient magnetic memory and logic devices. A persistent impediment to its practical applications is the reliance on external magnetic fields during the current-induced switching of exchange bias in perpendicularly magnetized structures. This study elucidates the achievement of a full electrical manipulation of the perpendicular exchange bias in the multilayers with an ultrathin antiferromagnetic layer. Owing to the anisotropic epitaxial strain in the 2-nm-thick IrMn3 layer, the considerable exchange bias effect is clearly achieved at room temperature. Concomitantly, a specific global uncompensated magnetization manifests in the IrMn3 layer, facilitating the switching of the irreversible portion of the uncompensated magnetization. Consequently, the perpendicular exchange bias can be manipulated by only applying pulsed current, notably independent of the presence of any external magnetic fields.

Tailoring of the Interfacial Dzyaloshinskii-Moriya Interaction in Perpendicularly Magnetized Epitaxial Multilayers by Crystal Engineering.

The interplay between the interfacial crystalline structure and Dzyaloshinskii-Moriya interaction (DMI) was investigated by Fe insertion in epitaxial Pt/Co/Ir perpendicular magnetized multilayers. The experimental results with the support of first-principles calculation indicate that the Fe/Ir interface exhibits a positive interfacial DMI (iDMI) originating from the fcc crystalline structure inserted by 2 monolayers (ML) Fe, while a negative one from the structure with a layer shifting of 1-ML Fe insertion. The total iDMI of the multilayers increases (decreases) due to the additive enhancement (competitive counteraction) between the iDMI of Fe/Ir and Pt/Co interfaces. Comparing the iDMI of single-crystalline and textured multilayers, the iDMI of multilayers is found to be particularly sensitive to the crystallinity nearby the heterointerfaces. This work is of vital importance to reveal a deeper insight into the physical mechanism of the iDMI and provides a viable strategy for tailoring the iDMI of the multilayers by crystal engineering.