Epitaxial orientation of MnAs layers grown on GaAs surfaces by means of solid-state crystallization

MnAs layers are grown on GaAs substrates employing solid-state epitaxy following deposition in a molecular-beam epitaxy system. The surface morphology varies markedly with the orientation of the substrates. This dependence is strictly dictated by the lattice mismatch in the direction of the c axis of MnAs. That the lattice mismatch is by far more important than interfacial atomic bonding in solid-state epitaxy provides an explanation that the minimization of the strain energy favors the M-plane orientation to the C-plane orientation on GaAs(111) despite the incompatible symmetries of the participating lattices.