Enhancing the interfacial perpendicular magnetic anisotropy and tunnel magnetoresistance by inserting an ultrathin LiF layer at an Fe/MgO interface

Perpendicular magnetic anisotropy (PMA) is becoming increasingly important in spintronics research, especially for high-density magnetoresistive random access memories (MRAMs). The PMA induced at an Fe/MgO interface is widely used in magnetic tunnel junctions. Here, we propose inserting an ultrathin LiF layer at the interface in an epitaxial Fe/MgO junction. With a 0.3 nm-thick LiF layer, a large intrinsic interface PMA energy, K-i,K-0, of 2.8 mJ/m(2) was achieved. We also found that the HE/MgO bilayer tunneling barrier exhibited a large tunnel magnetoresistance (TMR) effect, suggesting that a coherent spin-dependent tunneling process was maintained in the ultrathin LiF layer. Atomic-scale interface engineering using fluoride can further improve the PMA and TMR properties of spintronic devices.

Automated summary

Perpendicular magnetic anisotropy (PMA) is becoming increasingly important in spintronics research, especially for high-density magnetoresistive random access memories (MRAMs). This study proposes inserting an ultrathin LiF layer at the Fe/MgO interface and achieves a large intrinsic interface PMA energy. It is also found that a coherent spin-dependent tunneling process is maintained in the ultrathin LiF layer, leading to a large tunnel magnetoresistance (TMR) effect. Atomic-scale interface engineering using fluoride can further improve the PMA and TMR properties of spintronic devices.