Researchers at King Abdullah University of Science and Technology (KAUST) and Khalifa University of Science and Technology have investigated the transmission, tunneling magnetoresistance ratio and spin injection efficiency of bilayer LaI2 using a combination of first-principles calculations and the non-equilibrium Green’s function method.
Multilayer graphene electrodes were used by the team, to build a magnetic tunnel junction with bilayer LaI2 as ferromagnetic barrier. The magnetic tunnel junction reportedly proved to be a perfect spin filter device with an impressive tunneling magnetoresistance ratio of 653% under a bias of 0.1 V and a still excellent performance in a wide bias range. The team said that in combination with the obtained high spin injection efficiency, this could hold great potential from an application point of view.
Monolayer LaI2 is intrinsically ferromagnetic with a magnetic moment of 1 μB per formula unit. The TMR ratio of the MTJ was found to show a strong energy dependence, which can be explained by the obtained spin-resolved transmission distributions in the Brillouin zone.
In addition, the spin injection efficiency turns out to be very high for the P configuration, pointing to excellent potential of the MTJ as spin filter device.