The study of surface structure and Ga segregation in MnSb(0001) surface using first principles

Surface relaxation and surface formation energy were calculated for different
MnSb(0001)-(1×1) terminated surface using first-principles density functional theory.
After geometry optimization, we find that the Sb-terminated surface experiences smaller
relaxations and is much more stable under both Mn-rich and Sb-rich conditions. In
addition, Ga surface segregation through the MnSb film from the GaAs substrate is
confirmed from our experiments. Therefore, models were designed where Ga is
incorporated into the MnSb structure. Occupation of Mn substitutional sites just below the
surface is found to be favourable. A (2 × 2) surface reconstruction of n-MnSb was
experimentally observed using reflection high energy electron diffraction. Here, CASTEP
and CLEED are employed to understand the formation of the (2×2) surface