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 (001) 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 mu(B) which couple antiferromagnetically with their nearest neighbor As or Si atoms. (C) 2004 Elsevier B.V. All rights reserved.