Electronic and magnetic properties of the (111) surfaces of NiMnSb

TL;DR

This study uses ab-initio calculations to analyze the (111) surfaces of NiMnSb, revealing persistent surface states that disrupt half-metallicity and cause significant spin moment enhancements, differing from (001) surface behavior.

Contribution

It provides new insights into the electronic and magnetic surface properties of NiMnSb (111) surfaces, highlighting the persistence of surface states and their impact on half-metallicity.

Findings

Surface states within the minority gap persist several layers deep.

Half-metallicity is destroyed at the (111) surfaces due to surface states.

Surface spin moments are significantly enhanced.

Abstract

Using an ab-initio electronic structure method, I study the (111) surfaces of the half-metallic NiMnSb alloy. In all cases there is a very pronounced surface state within the minority gap which destroys the half-metallicity This state survives for several atomic layers below the surface contrary to the (001) surfaces where surface states were located only at the surface layer. The lower dimensionality of the surface leads in general to large enhancements of the surface spin moments.