High temperature ferromagnetism of Si/MnAs multilayers grown by molecular beam epitaxy

We report on high-temperature (>400 K) ferromagnetism in multilayers consisting of nonmagnetic Si and ferromagnetic MnAs, grown on GaAs (0 0 1) by molecular beam epitaxy. For a Si (1 nm)/MnAs (0.5 nm) multilayer, a coercive field of 344 Oe at 300 K is obtained from hysteresis loop measurements. For this ferromagnetic state, the electronic structure calculations assuming an epitaxial zincblende MnAs with volume conserving tetragonal distortion was performed using the full-potential linearized augmented plane-wave (FLAPW) method and yielded high spin magnetic moments values for the Mn atoms (3.39 and 3.74 μB), which couple antiferromagnetically with their nearest neighbor As or Si atoms.