Interface Design for Concurrent Realization of High Perpendicular Magnetic Anisotropy and Low Magnetic Damping in Fe/MgO

In spin transfer torque magnetoresistive random-access memory (STT-MRAM), the problem in the writing mechanism arises mainly due to the need for a large current to switch the magnetization direction of the free ferromagnet layer. As the device development of 1X nm cell diameter is preferable, keeping thermal stability to suppress data retention failures while maintaining a fast-switching mechanism becomes challenging, as the trade-off relationship between magnetic anisotropy and magnetic damping is ongoing. The Fe/MgO system is reported as a superior structure for magnetic tunnel junctions owing to the high tunnel magnetoresistance (TMR) and perpendicular magnetic anisotropy (PMA) originated from − coupling at the interface. Modifying the Fe/MgO interface offers the prospect of achieving high PMA and low magnetic damping simultaneously. This work focuses on exploring the interface modification effect, specifically by using N and F anions, i.e., the neighboring element of O from MgO, for high PMA and low magnetic damping from first principles. The result signifies that the LiF/MgO, BN/MgO, and MgN/MgO modifications achieve high PMA enhancement up to 350% while reducing magnetic damping by about 85% lower than that in the pristine Fe/MgO model. The origins are mainly driven by the band realignment of the interfacial Fe -orbital at around the Fermi level.