Epitaxial growth of magnetic Mn 2Sb 1− xAs x thin films on (0 0 1)GaAs

Abstract

We have succeeded in growing monocrystalline magnetic Mn 2Sb 1− x As x ( x=0∼0.21) thin films on GaAs(0 0 1) substrates by molecular beam epitaxy. The reflection high-energy electron diffraction patterns of these films have four-fold symmetry and indicate that the [1 0 0]Mn 2Sb 1− x As x direction is parallel to the [1 1 0]GaAs direction. From X-ray diffraction analysis, it was found that the growth orientation is the c-axis normal to the surface. The c-lattice parameter decreases from 0.654 nm to 0.644 nm when the As content increases from x=0 to 0.21. Superconducting quantum interference device measurements show an anomalous decrease of the magnetization with decreasing temperature below a critical temperature T C, which rises from 140 to 290 K with increasing As contents.