The Structures And Magnetic Properties Of3D Transition Metal Atom Chains Encapsulated By Au Nanotube

Transition metal monoatom chains (TM MAC) have got many attentions due to the properties such as quantum effects, small size effect, high spin polarization, tunneling effect and huge magnetism in recent years. They are exhibit the potential application in ultrahigh density magnetic storages, nano circuits and spin-polarized transport, etc.TM MACs are naturally unstable, so stabilizing these MACs without changing their unique physics properties is a critical step toward application. One main method of stabilizing a MAC is to encapsulate it into a stable nanotube.As one type of the metal nanotubes, Au nanotube shows very interesting properties such as high stability and good electrical conductivity. So encapsulating TM MAC with Au nanotube is a good choice.In order to have a more systematic understanding of the properties of3d transition metal monoatom chains (Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu) doped in Au (5,5) nanotubes (TM@Au), we calculated the geometric structure, energy, electronic and magnetic properties of TM@Au with density function theory of first principle. Based on the calculated results, the main conclusions were gained in this thesis as follows:1. The Sc@Au, Ti@Au, Fe@Au, Co@Au and Ni@Au are more stable in ferromagnetic (FM) state and V@Au, Cr@Au and Mn@Au are more stable in antiferromagnetic (AFM) state;2. The lattice constants of TM@Au in FM state decrease with the increase of the TM atomics number. The lattice constant of TM@Au in AFM state is bigger than that of the corresponding TM MAC in AFM state;3. The formation energy of the TM@Au is much bigger than that of the corresponding TM MAC both in FM state and AFM state, which means that the TM MAC encapsulated in Au (5,5) nanotube are more stable than the free TM MAC;4. The spin moments of TM atoms in TM@Au all decrease in the stable magnetic states which indicates that the interactions between TM atoms and Au atoms weaken the spin polarization of TM atoms;5. When the TM MACs are encapsulated in Au (5,5) nanotube the easy magnetization axes transfer from along the chain direction to perpendicular to the chain direction in FM states, while the reverse happens in AFM states.