Formation and Magnetic Interaction of Si/MnGe Core/Shell Nanowire Arrays

We present the preparation of MnGe coated Si nanowires (NWs) using molecular beam epitaxy. Uniformly dispersed silicon NW surfaces were initially covered by Ge, and then Si/MnGe core/shell NW heterostructures were fabricated by solid phase epitaxial growth. Morphology and the magnetic properties of the Si/MnGe core/shell NWs were investigated. The results of scanning electron microscope and transmission electron microscope revealed that the shell layer of NWs was agglomerated to form clusters, which were mainly comprised of Mn5Ge3 phase. Vibrating magnetometer and X-band ferromagnetic resonance measurements indicate that the Si/MnGe core/shell NWs exhibited a slight shape anisotropy along the geometrical wire axis.