First-principles investigations of electronic and magnetic properties of the FeRh/MgO (001) interface

Ab initio calculations of the electronic and magnetic properties of FeRh/MgO (001) interface are reported, focusing on the effects of different atomic terminations. It was found that the Fe-O termination is energetically the most stable. The change in the electronic properties at the interface is analyzed using the spin-polarized layer projected density of states, which shows that the spin polarization at the Fermi level is dominated by the spin-down t2g states. However, the magnetic moment of the interfacial Fe atom is not enhanced significantly compared to that of the inner layers. The difference of total energy between antiparallel (AP) and parallel (P) alignments of the magnetizations of the FeRh electrodes as function of MgO thickness shows that the AP configuration is the most stable and this interlayer exchange coupling decreases exponentially as predicted by the free-electron theory. Finally, Löwdin analysis of the electron density shows that the charge is transferred from the interface MgO layer to that of FeRh and confirm the change of the interface states at the vicinity of the Fermi level.