Temperature dependence of the thermopower and its variation of the Au atomic contact

We performed simultaneous measurements of the thermopower, and conductance of Au atomic contacts during the self-breaking process under temperature control. During the whole measurement temperature regime (290–330 K), the thermopower randomly fluctuated from positive to negative in sign, and the average thermopower was negligibly small with respect to the variation of the thermopower of the contact. Meanwhile, the standard deviation of the thermoelectric voltage increased linearly with the temperature difference across the contacts. Above 320 K, we observed a decrease in the standard deviation of thermopower, which suggested a decrease in the density of defects near the contacts. The linear increase in the standard deviation of the thermoelectric voltage, and the decrease in the standard deviation of the thermopower above 320 K, indicate that the standard deviation of thermopower provides insight into the thermopower of an individual Au atomic contact and the atomic structure of ...

Ryuji Matsushita, Satoshi Kaneko, Shintaro Fujii, Hisao Nakamura and Manabu Kiguchi

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Field electron emission enhancement of graphenated MWCNTs emitters following their decoration with Au nanoparticles by a pulsed laser ablation process

A plasma-enhanced chemical vapor deposition (PECVD) process was adapted to alter the growth of multiwall carbon nanotubes (MWCNTs) so that graphene sheets grow out of their tips. Gold nanoparticle (Au-NP) decoration of graphenated MWCNTs (g-MWCNTs) was obtained by subsequent decoration by a pulsed laser deposition (PLD) process. By varying the number of laser ablation pulses ( N Lp ) in the PLD process, we were able to control the size of the gold nanoparticles and the surface coverage of the decorated g-MWCNTs. The presence of Au-NPs, preferentially located at the tip of the g-MWCNTs emitters, is shown to significantly improve the field electron emission (FEE) properties of the global g-MWCNT/Au-NP nanohybrid films. Indeed, the electric field needed to extract a current density of 0.1 μ A cm − 2 from the g-MWCNT/Au-NP films was decreased from 2.68 V μ m −1 to a value as low as 0.96 V μ m −1 . On the other ha...

L-A Gautier, V Le Borgne, N Delegan, R Pandiyan and M A El Khakani

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Effect of hydration repulsion on nanoparticle agglomeration evaluated via a constant number Monte–Carlo simulation

The effect of hydration repulsion on the agglomeration of nanoparticles in aqueous suspensions was investigated via the description of agglomeration by the Smoluchowski coagulation equation using constant number Monte–Carlo simulation making use of the classical DLVO theory extended to include the hydration repulsion energy. Evaluation of experimental DLS measurements for TiO 2 , CeO 2 , SiO 2 , and α -Fe 2 O 3 (hematite) at high IS (up to 900 mM) or low | ζ -potential| (≥1.35 mV) demonstrated that hydration repulsion energy can be above electrostatic repulsion energy such that the increased overall repulsion energy can significantly lower the agglomerate diameter relative to the classical DLVO prediction. While the classical DLVO theory, which is reasonably applicable for agglomeration of NPs of high | ζ -potential| (∼>35 mV) in suspensions of low IS (∼<1 mM), it can overpredict agglomerate sizes by up to a fact...

Haoyang Haven Liu, Jacob Lanphere, Sharon Walker and Yoram Cohen

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Soliton instability and fold formation in laterally compressed graphene

We investigate—through simulations and analytical calculations—the consequences of uniaxial lateral compression applied to the upper layer of multilayer graphene. The simulations of compressed graphene show that strains larger than 2.8% induce soliton-like deformations that further develop into large, mobile folds. Such folds were indeed experimentally observed in graphene and other solid lubricants two-dimensional (2D) materials. Interestingly, in the soliton-fold regime, the shear stress decreases with the strain s , initially as ##IMG## [http://ift.tt/1xJ2yog] {${{s}^{-2/3}}$} and rapidly going to zero. Such instability is consistent with the recently observed negative dynamic compressibility of 2D materials. We also predict that the curvatures of the soliton-folds are given by ##IMG## [http://ift.tt/14t2ddz...] {${{r}_{c}}=\delta \sqrt{\beta /2\alpha },$}

Amauri Libério de Lima, Lucas A M Müssnich, Taíse M Manhabosco, Hélio Chacham, Ronaldo J C Batista and Alan Barros de Oliveira

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Low-cost fabrication technologies for nanostructures: state-of-the-art and potential

In the last decade, some low-cost nanofabrication technologies used in several disciplines of nanotechnology have demonstrated promising results in terms of versatility and scalability for producing innovative nanostructures. While conventional nanofabrication technologies such as photolithography are and will be an important part of nanofabrication, some low-cost nanofabrication technologies have demonstrated outstanding capabilities for large-scale production, providing high throughputs with acceptable resolution and broad versatility. Some of these nanotechnological approaches are reviewed in this article, providing information about the fundamentals, limitations and potential future developments towards nanofabrication processes capable of producing a broad range of nanostructures. Furthermore, in many cases, these low-cost nanofabrication approaches can be combined with traditional nanofabrication technologies. This combination is considered a promising way of generating inn...



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Synthesis of graphene-supported one-dimensional nanoporous Pt based catalysts, and their enhanced performance on methanol electro-oxidation

A novel approach is developed to synthesize PtIr or Pt nanowires (NWs) supported on the reduced graphene oxide (RGO) using Te NWs as template based on the replacement reaction. The resulting RGO-supported PtIr and Pt electrocatalysts are characterized by transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy and electrochemical techniques. TEM images show that these Pt based catalysts are uniformly distributed in the matrix of graphene with a characteristic of one-dimensional (1D) nanoporous structure. As one of promising anode materials used in the direct methanol fuel cells, these 1D nanoporous PtIr/RGO (or Pt/RGO) hybrids exhibit an enlarged electroactive surface and enhanced catalytic activity toward the methanol reaction relative to those PtIr or Pt NWs without graphene support.

Liji Hong, Yanfei Hao, Yunyun Yang, Junhua Yuan and Li Niu

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Probing Local Bias-Induced Transitions Using Photothermal Excitation Contact Resonance Atomic Force Microscopy and Voltage Spectroscopy

ACS Nano

DOI: 10.1021/nn506753u

Qian Li, Stephen Jesse, Alexander Tselev, Liam Collins, Pu Yu, Ivan Kravchenko, Sergei V. Kalinin and Nina Balke

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Sb-Induced Phase Control of InAsSb Nanowires Grown by Molecular Beam Epitaxy

Nano Letters

DOI: 10.1021/nl5040946

Q. D. Zhuang, Ezekiel A. Anyebe, R. Chen, H. Liu, Ana M. Sanchez, Mohana K. Rajpalke, Tim D. Veal, Z. M. Wang, Y. Z. Huang and H. D. Sun

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Robust Two-Dimensional Topological Insulators in Methyl-Functionalized Bismuth, Antimony, and Lead Bilayer Films

Nano Letters

DOI: 10.1021/nl504037u

Yandong Ma, Ying Dai, Liangzhi Kou, Thomas Frauenheim and Thomas Heine

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Impact of the Alkali Cation on the Oscillatory Electro-Oxidation of Ethylene Glycol on Platinum

The Journal of Physical Chemistry C

DOI: 10.1021/jp5105505

Elton Sitta, Raphael Nagao, István Z. Kiss and Hamilton Varela

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Wet Chemical Functionalization of GaP(111)B through a Williamson Ether-Type Reaction

The Journal of Physical Chemistry C

DOI: 10.1021/jp509015x

Elizabeth S. Brown, Sabrina L. Peczonczyk and Stephen Maldonado

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Synchronous Formation of ZnO/ZnS Core/Shell Nanotube Arrays with Removal of Template for Meliorating Photoelectronic Performance

The Journal of Physical Chemistry C

DOI: 10.1021/jp510835n

Samar Tarish, Zhijie Wang, Ahmed Al-Haddad, Chengliang Wang, Adriana Ispas, Henry Romanus, Peter Schaaf and Yong Lei

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Surface Reduction of Neptunium Dioxide and Uranium Mixed Oxides with Plutonium and Thorium by Photocatalytic Reaction with Ice

The Journal of Physical Chemistry C

DOI: 10.1021/jp508239u

Pelin Cakir, Rachel Eloirdi, Frank Huber, Rudy J. M. Konings and Thomas Gouder

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Phase Behavior and Electrochemical Characterization of Blends of Perfluoropolyether, Poly(ethylene glycol), and a Lithium Salt

Chemistry of Materials

DOI: 10.1021/cm504228a

Dominica H. C. Wong, Alessandra Vitale, Didier Devaux, Austria Taylor, Ashish A. Pandya, Daniel T. Hallinan, Jacob L. Thelen, Sue J. Mecham, Simon F. Lux, Alexander M. Lapides, Paul R. Resnick, Thomas J. Meyer, Robert M. Kostecki, Nitash P. Balsara and Joseph M. DeSimone

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Mg Alloying in SnTe Facilitates Valence Band Convergence and Optimizes Thermoelectric Properties

Chemistry of Materials

DOI: 10.1021/cm504112m

Ananya Banik, U. Sandhya Shenoy, Shashwat Anand, Umesh V. Waghmare and Kanishka Biswas

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Enhanced Photochemistry of Ethyl Chloride on Ag Nanoparticles

Nano Letters

DOI: 10.1021/nl503700y

Gil Toker, Alexander Bespaly, Liat Zilberberg and Micha Asscher

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Suppressing a Charge Density Wave by Changing Dimensionality in the Ferecrystalline Compounds ([SnSe]1.15)1(VSe2)n with n = 1, 2, 3, 4

Nano Letters

DOI: 10.1021/nl503708j

Matthias Falmbigl, Andreas Fiedler, Ryan E. Atkins, Saskia F. Fischer and David C. Johnson

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Tunable Ultrasmall Visible-to-Extended Near-Infrared Emitting Silver Sulfide Quantum Dots for Integrin-Targeted Cancer Imaging

ACS Nano

DOI: 10.1021/nn5071183

Rui Tang, Jianpeng Xue, Baogang Xu, Duanwen Shen, Gail P. Sudlow and Samuel Achilefu

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Anchoring Cobalt Nanocrystals through the Plane of Graphene: Highly Integrated Electrocatalyst for Oxygen Reduction Reaction

Chemistry of Materials

DOI: 10.1021/cm503988n

Li-Bing Lv, Tian-Nan Ye, Ling-Hong Gong, Kai-Xue Wang, Juan Su, Xin-Hao Li and Jie-Sheng Chen

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Understanding the Stabilization of Single-Walled Carbon Nanotubes and Graphene in Ionic Surfactant Aqueous Solutions: Large-Scale Coarse-Grained Molecular Dynamics Simulation-Assisted DLVO Theory

The Journal of Physical Chemistry C

DOI: 10.1021/jp5093477

Chih-Jen Shih, Shangchao Lin, Michael S. Strano and Daniel Blankschtein

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