Interplay of elastic and magnetic properties in MnAs/GaAs heterostructures

Ferromagnetic α-MnAs is a good candidate for electrical spin injection into semiconductors. Due to the epitaxial constraints in MnAs/GaAs(0 0 1) heterostructures, where the in-plane lattice-spacings a and c cannot change during the first-order phase transition, the α- and β-phases coexist over a wide temperature range (10–40°C) and exhibit a unique periodic stripe pattern along MnAs[0 0 0 1]. This coexistence of elastic domains of two phases minimizes the elastic energy. The MnAs-on-GaAs(0 0 1) films exhibit an additional out-of-plane component of the magnetization which led us to a new concept for programmable magneto-logic devices.