The Ni80Nb20 films were prepared by ion beam assisted deposition (IBAD) with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 keV ...The Ni80Nb20 films were prepared by ion beam assisted deposition (IBAD) with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 keV to 8 keV. When bombarded by Ar+ ions of 8 keV during deposition, a new crystalline phase with hcp structure was obtained, of which the lattice parameters are a=0.286 nm and c=0.483 nm, different from those of the similar A3B-type hcp phase previously reported. The experimental results were discussed in terms of thermodynamics and restricted kinetic conditions in the far-from-equilibrium process of IBAD. The formation of hep phase may also be related to the valence electron effect.展开更多
基金The work was supported in part by the National Natural Sci ence Foundation of China(No.19875027)The Ministry of Science and Technology of China(No.G200067207-1),by the Adninistration of Tsinghua University.
文摘The Ni80Nb20 films were prepared by ion beam assisted deposition (IBAD) with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 keV to 8 keV. When bombarded by Ar+ ions of 8 keV during deposition, a new crystalline phase with hcp structure was obtained, of which the lattice parameters are a=0.286 nm and c=0.483 nm, different from those of the similar A3B-type hcp phase previously reported. The experimental results were discussed in terms of thermodynamics and restricted kinetic conditions in the far-from-equilibrium process of IBAD. The formation of hep phase may also be related to the valence electron effect.
