par Byshkin, Maxim 
;Zhu, Beien ;Hou, Marc
Référence Journal of Materials Science, 48, 2, page (866-875)
Publication Publié, 2013-01
;Zhu, Beien ;Hou, Marc Référence Journal of Materials Science, 48, 2, page (866-875)
Publication Publié, 2013-01
Article révisé par les pairs
| Résumé : | The effect of encapsulation in carbon nanotubes on Fe-Ni nanoparticles (NPs), NP assemblies and nanowires (NWs) is studied by means of atomistic simulations with empirical potentials. The BCC Fe, L10, FeNi, L1 2 FeNi3 and FCC Ni stable phases of the bulk alloy are retrieved for both the freestanding (FS) and the encapsulated nanoalloys. As it requires large morphological changes, the BCC/L10 transition may be inhibited by the confinement in a nanotube. The results indicate that encapsulation has the effect to enhance Fe segregation at compositions intermediate between stable phases. When the nanotube is too narrow, encapsulated NWs do not support a cubic structure. They consist in coaxial layers with a central straight atomic row aligning with the tube axis. Each layer displays a helical structure which can be equivalently viewed as a folded atomic plane with low Miller indices. Such ultrathin helical Fe-Ni NWs, FS as well as encapsulated, behave as almost ideal solid solutions over the whole range of compositions. © 2012 Springer Science+Business Media, LLC. |
