The role of magnetoelastic and magnetostrictive energies in the magnetization process of MnAs/GaAs epilayers.

In this work we present a detailed study of the anisotropic magnetic behavior of MnAs epilayers grown by molecular beam epitaxy on GaAs(001) and GaAs(111)B substrates. An extended approach of the Stoner-Wohlfarth model is used to simulate magnetic hysteresis loops of MnAs epilayers for temperatures around the magnetostructural phase transition. We demonstrate that magnetoelastic and magnetostrictive energy contributions to the magnetic free energy density are crucial to correctly describe the magnetization of both kinds of MnAs epilayers.