Ab-initio study of electronic and magnetic properties of Mn${}_2$RuZ/MgO (001) heterojunctions (Z= Al, Ga, Si, Ge)

Abstract

Using first-principles calculations, we studied Mn${}_2$RuZ (Z=Al, Ga, Si, Ge) and their heterojunctions with MgO along (001) direction. All these alloys possess Hg${}_2$CuTi-type inverse Heusler alloy structure and ferrimagnetic ground state. Our study reveals the half-metallic electronic structure with highly spin-polarized ${\Delta }_1$ band, which is robust against atomic disorder. Next we studied the electronic structure of Mn${}_2$RuAl/MgO and Mn${}_2$RuGe/MgO heterojunctions. We found that the MnAl- or MnGe-terminated interface is energetically more favorable compared to the MnRu-terminated interface. Interfacial states appear at the Fermi level in the minority-spin gap for the Mn${}_2$RuGe/MgO junction. We discuss the origin of these interfacial states in terms of local environment around each constituent atom. On the other hand, in the Mn${}_2$RuAl/MgO junction, high spin polarization of bulk Mn${}_2$RuAl is preserved independent of its termination.

15 pages, 7 figures

References in corpus (3)

• Half-metallic ferromagnets for magnetic tunnel junctions
• Exchange interactions and Curie temperatures in Mn2CoZ compounds
• Structural stability, magnetic and electronic properties of Co2MnSi(001)/MgO heterostructures: A density functional theory study

Cited by in corpus (3)

• Ballistic spin-transport properties of magnetic tunnel junctions with MnCr-based ferrimagnetic quaternary Heusler alloys
• Gateway to all-optical spin switching in Heusler ferrimagnets: Pancharatnam-Berry tensor and magnetic moment ratio
• IrCrMnZ (Z=Al, Ga, Si, Ge) Heusler alloys as electrode materials for MgO-based magnetic tunneling junctions: A first-principles study