Cu atoms induce a new reconstruction in the MnGa(001) surface: An ab-initio study

MnGa alloys possess a set of properties that give them a wide range of applications: from Magnetic Tunnel Junctions (MJTs) to semiconductor-magnetic hybrid devices. In the present study, we report a first-principles investigation on a surface reconstruction based on the L1 0 -ordered MnGa (001) with the incorporation of Cu atoms at the surface. We present a comprehensive analysis of the viability of all the possible reconstructions, as well as the structural, electronic, and magnetic properties of the most stable one: a 1 × 2 reconstruction with a Cu-by-Ga substitution at the surface. We propose that this structure may pose as a magnetic catalyst, which would add yet another interesting application to MnGa alloys. • A 1 × 1 and a 1 × 2 Cu-substituted reconstructions are predicted for the MnGa(001) surface. • Theoretical STM images evidence the formation of a 1 × 2 row-like pattern. • Mn and Cu atoms couple antiferromagnetically and diamagnetically, respectively. • The 1 × 2 model has highly localized spin-up electrons at the surface and an electronegative Cu atom.