We have carried out postgrowth annealing studies on heteroepitaxial MnAs thin films deposited on GaAs(001) and Si(001) by molecular-beam epitaxy. Before annealing, a paramagnetic behavior is exhibited for MnAsSi(001), whereas a ferromagnetic behavior is observed for MnAsGaAs(001). The paramagnetic Β - MnAs phase domains of the as-grown MnAsGaAs(001) sample disappear completely after postgrowth annealing. Surprisingly, after postgrowth annealing, the crystal orientation of the MnAsSi(001) film changes, and is accompanied by a shift from paramagnetic to ferromagnetic behavior. We attribute these observations to relaxation of the biaxial strain associated with the substrates.
ASJC Scopus subject areas
- Physics and Astronomy(all)