9,637 research outputs found
Tailoring palladium nanocontacts by electromigration
Electromigration is employed in nanoelectronics for transforming narrow metallic wires into electrodes separated by a few nanometers gap. In this work, we fabricate either nanoconstrictions or nanogap electrodes by performing electromigration in palladium nanowires. The device resistance and the cross section of the initial nanowires allow us to regulate the conditions for transforming deterministically each nanowire in a specific final device. The resulting samples show unique electrical transport characteristics and could be used in multiple nanoelectronics research applications, from ballistic transport to electrodes for single molecular devices.Fil: Arzubiaga, Libe. CIC nanoGUNE; EspañaFil: Golmar, Federico. Instituto Nacional de TecnologĂa Industrial; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Llopis, Roger. CIC nanoGUNE; EspañaFil: Casanova, FĂ©lix. CIC nanoGUNE; España. Basque Foundation for Science; EspañaFil: Hueso, Luis E.. CIC nanoGUNE; España. Basque Foundation for Science; Españ
Thermal Conductivity and Thermal Rectification in Graphene Nanoribbons: a Molecular Dynamics Study
We have used molecular dynamics to calculate the thermal conductivity of
symmetric and asymmetric graphene nanoribbons (GNRs) of several nanometers in
size (up to ~4 nm wide and ~10 nm long). For symmetric nanoribbons, the
calculated thermal conductivity (e.g. ~2000 W/m-K @400K for a 1.5 nm {\times}
5.7 nm zigzag GNR) is on the similar order of magnitude of the experimentally
measured value for graphene. We have investigated the effects of edge chirality
and found that nanoribbons with zigzag edges have appreciably larger thermal
conductivity than nanoribbons with armchair edges. For asymmetric nanoribbons,
we have found significant thermal rectification. Among various
triangularly-shaped GNRs we investigated, the GNR with armchair bottom edge and
a vertex angle of 30{\deg} gives the maximal thermal rectification. We also
studied the effect of defects and found that vacancies and edge roughness in
the nanoribbons can significantly decrease the thermal conductivity. However,
substantial thermal rectification is observed even in the presence of edge
roughness.Comment: 13 pages, 5 figures, slightly expanded from the published version on
Nano Lett. with some additional note
Mechanical properties and thermal conductivity of graphitic carbon nitride: A molecular dynamics study
Graphitic carbon nitride nanosheets are among 2D attractive materials due to
presenting unusual physicochemical properties.Nevertheless, no adequate
information exists about their mechanical and thermal properties. Therefore, we
used classical molecular dynamics simulations to explore the thermal
conductivity and mechanical response of two main structures of single-layer
triazine-basedg-C3N4 films.By performing uniaxial tensile modeling, we found
remarkable elastic modulus of 320 and 210 GPa, and tensile strength of 47 GPa
and 30 GPa for two different structures of g-C3N4sheets. Using equilibrium
molecular dynamics simulations, the thermal conductivity of free-standing
g-C3N4 structures were also predicted to be around 7.6 W/mK and 3.5 W/mK. Our
study suggests the g-C3N4films as exciting candidate for reinforcement of
polymeric materials mechanical properties
On the Thermal Stability of Graphone
Molecular dynamics simulation is used to study thermally activated migration
of hydrogen atoms in graphone, a magnetic semiconductor formed of a graphene
monolayer with one side covered with hydrogen so that hydrogen atoms are
adsorbed on each other carbon atom only. The temperature dependence of the
characteristic time of disordering of graphone via hopping of hydrogen atoms to
neighboring carbon atoms is established directly. The activation energy of this
process is found to be Ea=(0.05+-0.01) eV. The small value of Ea points to
extremely low thermal stability of graphone, this being a serious handicap for
practical use of the material in nanoelectronics.Comment: 3 figure
Nanotrench for nano and microparticle electrical interconnects
We present a simple and versatile patterning procedure for the reliable and reproducible fabrication of high aspect ratio (10 4 ) electrical interconnects that have separation distances down to 20 nm and lengths of several hundreds of microns. The process uses standard optical lithography techniques and allows parallel processing of many junctions, making it easily scalable and industrially relevant. We demonstrate the suitability of these nanotrenches as electrical interconnects for addressing micro and nanoparticles by realizing several circuits with integrated species. Furthermore, low impedance metal-metal low contacts are shown to be obtained when trapping a single metal-coated microsphere in the gap, emphasizing the intrinsic good electrical conductivity of the interconnects, even though a wet process is used. Highly resistive magnetite-based nanoparticles networks also demonstrate the advantage of the high aspect ratio of the nanotrenches for providing access to electrical properties of highly resistive materials, with leakage current levels below 1 pA. © 2010 IOP Publishing Ltd
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