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 Physics , 2006, DOI: 10.1103/PhysRevLett.96.106804 Abstract: We analyze a new family of carbon nanotube-based molecular wires, formed by encapsulating metallocene molecules inside the nanotubes. Our simulations, that are based on a combination of non-equilibrium Green function techniques and density functional theory, indicate that these wires can be engineered to exhibit desirable magnetotransport effects for use in spintronics devices. The proposed structures should also be resilient to room-temperature fluctuations, and are expected to have a high yield.
 - , 2017, Abstract: 基于密度泛函理论框架下的第一性原理计算，系统地研究了过渡金属(TM) Mn和Co线性单原子链填充Cu纳米管所形成复合结构的稳定性和磁性。相对于孤立单原子链，复合结构的结合能大大增加，表明Cu纳米管的包裹使得Mn和Co单原子链的稳定性显著增强。随着管内TM原子间距的增加，Mn@CuNT复合结构表现出由反铁磁向铁磁的磁相变，而Co@CuNT复合结构则表现出由铁磁向反铁磁的磁相变。相对于自由单原子链，复合结构的磁晶各向异性能显著增强，且Cu纳米管的包裹使得Mn原子链的易磁化方向发生了改变。By using first-principles calculations based on density-functional theory, we have systematically investigated the stability and magnetic properties of transition metal (TM) Mn and Co linear monoatomic chains encapsulated into copper nanotube. The results indicate that the binding energies of the TM@CuNT hybrid structures are remarkably higher than those of freestanding TM chains, suggesting that the TM chains are signi？cantly stabilized by the copper nanotube coating. The magnetic phase transitions from antiferromagnetic state to ferromagnetic state in Mn@CuNT hybrid structure and from ferromagnetic state to antiferromagnetic state in Co@CuNT hybrid structure take place when the TM-TM atom distances increase. The magnetic phase transition can be understood by RKKY model. The magnetocrystalline anisotropy energies (MAE) of TM@CuMT hybrid structures are all remarkably enhanced compared to those of free TM chains and a trend that longer TM-TM distance results in a larger MAE. Furthermore, the easy magnetization axis of Mn@CuNT hybrid structure switches from that perpendicular to the axis in the free Mn linear chain to that along the axis, which makes them possible for practical application.
 Nanoscale Research Letters , 2011, Abstract: The changes of dynamical behaviour of a single fullerene molecule inside an armchair carbon nanotube caused by the structural Peierls transition in the nanotube are considered. The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory. Significant changes of the barriers for motion along the nanotube axis and rotation of these fullerenes inside the (8,8) nanotube are found at the Peierls transition. It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude. The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.
 Physics , 2011, DOI: 10.1186/1556-276X-6-216 Abstract: The changes of dynamical behaviour of a single fullerene molecule inside an armchair carbon nanotube caused by the structural Peierls transition in the nanotube are considered. The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory. Significant changes of the barriers for motion along the nanotube axis and rotation of these fullerenes inside the (8,8) nanotube are found at the Peierls transition. It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude. The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.
 Physics , 2009, DOI: 10.1021/nl080850t Abstract: The charge transport properties of single superconducting tin nanowires, encapsulated by multiwalled carbon nanotubes have been investigated by multi-probe measurements. The multiwalled carbon nanotube protects the tin nanowire from oxidation and shape fragmentation and therefore allows us to investigate the electronic properties of stable wires with diameters as small as 25 nm. The transparency of the contact between the Ti/Au electrode and nanowire can be tuned by argonion etching the multiwalled nanotube. Application of a large electrical current results in local heating at the contact which in turn suppresses superconductivity.
 Brazilian Journal of Physics , 2008, DOI: 10.1590/S0103-97332008000100014 Abstract: this work aim is to determine how a c60 fullerene, encapsulated into a (10,10) carbon nanotube, can be ballistically expelled from it by using a colliding capsule. initially, the c60 fullerene is positioned at rest inside the nanotube. the capsule, also starting from rest but outside of the nanotube, is put in a position such that it can be trapped towards the interior of the nanotube by attraction forces between their atoms. the energy gain associated to the capsule penetration is kinetic energy, giving rise to a high velocity for it. when the capsule reaches the c60 fullerene, it transfers energy to it in an amount that enables the fullerene to escape from the nanotube. the mechanical behavior was simulated by classical molecular dynamics. the intermolecular interactions are described by a van der waals potential while the intramolecular interactions are described by an empirical tersoff-brenner potential for the carbon system.
 Physics , 2011, DOI: 10.1088/0953-8984/23/26/265302 Abstract: Monoatomic chains of molybdenum encapsulated in single walled carbon nanotubes of different chiralities are investigated using density functional theory. We determine the optimal size of the carbon nanotube for encapsulating a single atomic wire, as well as the most stable atomic arrangement adopted by the wire. We also study the transport properties in the ballistic regime by computing the transmission coefficients and tracing them back to electronic conduction channels of the wire and the host. We predict that carbon nanotubes of appropriate radii encapsulating a Mo wire have metallic behavior, even if both the nanotube and the wire are insulators. Therefore, encapsulating Mo wires in CNT is a way to create conductive quasi one-dimensional hybrid nanostructures.
 Physics , 2012, Abstract: We investigate the geometry, stability, electronic structure and optical properties of C24H12 coronenes encapsulated in a single-wall (19,0) carbon nanotube. By an adequate combination of advanced electronic-structure techniques, involving weak and van derWaals interaction, as well as many-body effects for establishing electronic properties and excitations, we have accurately characterized this hybrid carbon nanostructure, which arises as a promising candidate for opto-electronic nanodevices. In particular, we show that the structure of the stacked coronenes inside the nanotube is characterized by a rotation of every coronene with respect to its neighbors through van derWaals interaction, which is of paramount importance in these systems. We also suggest a tentative modification of the system in order this particular rotation to be observed experimentally. A comparison between the calculated many-body excitation spectrum of the systems involved reveals a pronounced optical red-shift with respect to the coronene-stacking gas-phase. The origin of this red-shift is explained in terms of the confinement of the coronene molecules inside the nanotube, showing an excellent agreement with the available experimental evidence.
 物理学报 , 2008, Abstract: The structure and thermal stability of gold nanowire encapsulated in single-walled carbon nanotube (SWCNT) were studied by molecular dynamics simulations. A (8,8) SWCNT was used as a model system and the simulated annealing method was employed to find the stable structure of the gold nanowire at room temperature. Ourresults show that the gold nanowire encapsulated in a (8,8) SWCNT has a cylindrical shape and a helical shell structure. The helical-shell nanowire is thermally stable at temperatures much higher than the melting temperature of its bulk counterpart and is different from the gold nanowire formed in free space without the nanotube envelope. We also found that the spiral nanowire undergoes structural changes at higher temperatures.
 Physics , 2005, DOI: 10.1016/j.cplett.2005.08.153 Abstract: We study the energetics of acetylene (${\rm C_2H_2}$) molecules inside a carbon nanotube (CNT) using the {\it ab initio} pseudopotential method. The encapsulation energy of a single ${\rm C_2H_2}$ molecule into the nanotube and the formation energy of ${\rm (C_2H_2)}_n$@CNT are calculated. We investigate whether a polyacetylene chain can be produced by fusion of the close-packed acetylene molecules inside the CNT and find that there is practically no activation barrier to polymerization. We propose to employ this method to obtain straight, perfectly isolated, and single-stranded polyacetylene chains encapsulated inside CNTs, which may be used for molecular electronic devices.
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