Structures of ultrathin copper nanotubes

Abstract

We have performed atomistic simulations for helical multi-shell (HMS) Cu nanowires and nanotubes. Our investigation on HMS Cu nanowires and nanotubes has revealed some physical properties that were not dealt in previous works that considered metal nanowires. As the diameter of HMS nanowires increased, their cohesive energy per atom and optimum lattice constant decreased. As the diameter of HMS nanotubes increases, their cohesive energy per atom decreased but optimum lattice constant increased. Shell-shell or core-shell interactions mainly affected on the lattice constant and the diameter of HMS nanowires or nanotubes. This study showed that HMS nanotubes for materials of fcc metal crystals can be maintained when forces exerted on atoms of inner shell of the HMS nanotubes are zero or act on the direction of the outside.

Pentagonal nanowires: A first-principles study of the atomic and electronic structure

“…18,19,20,21,22,23,24,25,26 Whether the pentagonal structures predicted earlier by empirical methods 16,27,28,29 are common to other elements and can be understood from more fundamental principles have become an important issue. In this paper we address this question by using the first-principles plane wave calculations within the density functional theory.…”

Ultrathin Nanowires—A Materials Chemistry Perspective

“…[16] Nevertheless, what really inspires a large number of scientists is the possibility of synthesizing, stabilizing, and isolating large numbers of ultrathin nanowires with the unprecedented structures predicted by theory. [17] Most of the work has been performed on metallic nanowires, from elements such as Al, [17] Pb, [17,18] Bi, [19] Si, [20][21][22] Rh, [23] Ag, [24] Cu, [25,26] and Au. [27,28] In the case of Al, Pb, Au, Cu, Rh, and Bi, wires below a certain size have been found to preferentially adopt a multiwalled architecture.…”

Fullerene Shuttle Memory Device: Classical Molecular Dynamics Study

“…The most suitable field was the 1.75 ps pulse of the 0.013 eV/Å per atom (0.47 eV/Å per C 36 ) in our MD simulations. The C 36 was not return by the weak turn-off field of 0.008 eV/Å per atom (0.324 eV/Å per C 36 ) in our MD simulations during 1.25 ps. Under a strong turn-off field of 0.016 eV/Å per atom (0.576 eV/Å per C 36 ) during 1.75 ps, the C 36 returned but three carbon atoms of the C 36 made the covalent bonds with three atoms of the C 640 capsule.…”

“…We used both steepest descent (SD) and MD methods. The MD simulations used the same MD methods as were used in our previous works [34][35][36][37][38]. The MD code used the velocity Verlet algorithm, a Gunsteren-Berendsen thermostat to control temperature and neighbor lists to improve computing performance.…”

“…The ext E on the atoms of the C 640 capsule was zero whereas the first deviation of the ext E on the atoms of the C 36 was a constant value. This assumption means that an external field only accelerates the encapsulated C 36 . We observed the central position variations of the C 36 along the z-axis as a function of the MD time with the external force applied to the C 36 fullerene.…”