Electronic structures and Magnetism of surfaces, interfaces and nano-systems

J. I. Lee, Y-J. Jin, and C. Jo

Department of Physics, Inha University, Incheon 402-751

We have investigated the electronic structures and magnetism for the surfaces of Fe₅₀Co₅₀ and the interfaces of zinc-blende CrAs on GaAs(001) by first-principles energy  band method. The magnetic properties of the Fe-Co binary nanowires and Fe-filled carbon nanotubes (CNTs) were also studied. It was found, by total energy calculations, the B₂ structure is more stable than L1₀ structure for the slab system of Fe₅₀Co₅₀. At the surface and interface layers of CrAs on GaAs(001) system, we also find that the half-metallic character retains.

For the Fe-Co binary nanowires, at the composition of Co 20 %, the nanowire has nearly half-metallic property with the spin polarization of 90 %. For the Fe nanowires encapsulated in CNTs, the calculated magnetic moment and spin polarization of the nanowires loosely wrapped by CNTs are larger than those for nanowires tightly encapsulated in CNTs. The results indicate that the Fe-filled CNTs with a hollow region between the Fe wire and the C shell are more useful for practical applications.