Fate of Half-Metallicity Near Interfaces: The Case of NiMnSb/MgO and NiMnSi/MgO

• Published in: ACS applied materials & interfaces Vol. 6; no. 16; pp. 14516 - 14521
• Main Authors: Zhang, Rui-Jing, Eckern, Ulrich, Schwingenschlögl, Udo
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 27-08-2014
• Subjects: half metal; Heusler alloy; heterostructure; density functional theory
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am5037753

The electronic and magnetic properties of the interfaces between the half-metallic Heusler alloys NiMnSb, NiMnSi, and MgO have been investigated using first-principles density-functional calculations with projector augmented wave potentials generated in the generalized gradient approximation. In the case of the NiMnSb/MgO (100) interface, the half-metallicity is lost, whereas the MnSb/MgO contact in the NiMnSb/MgO (100) interface maintains a substantial degree of spin polarization at the Fermi level (∼60%). Remarkably, the NiMnSi/MgO (111) interface shows 100% spin polarization at the Fermi level, despite considerable distortions at the interface, as well as rather short Si/O bonds after full structural optimization. This behavior markedly distinguishes NiMnSi/MgO (111) from the corresponding NiMnSb/CdS and NiMnSb/InP interfaces.