Search results for " nanowires"
showing 10 items of 83 documents
Simulation of Young’s moduli for hexagonal ZnO [0 0 0 1]-oriented nanowires: first principles and molecular mechanical calculations
2017
The authors thank A Gulans, B Polyakov and S Vlassov for stimulating discussions. This study has been supported by the ERA.Net RUS Plus project No. 237 Watersplit. AB, RE and SL acknowledge the financial support by the Russian Foundation for Basic Research (Grant No. 17-03-00130-a) and the assistance of the Saint Petersburg State University Computer Center in the accomplishment of high-performance computations.
Growth and Characterization of Ordered PbO[sub 2] Nanowire Arrays
2008
Large arrays of PbO 2 nanowires having high aspect ratios (length-to-width ratio) were grown by potentiostatic electrodeposition into anodic alumina templates under anodic polarization. Different electrolytic solutions were used in order to obtain nanowires of pure α-PbO 2 , pure β-PbO 2 , and a a + β mixture, We have found that, in a lead nitrate bath, a crystallographic structure of nanowires depends on pH; this latter was varied adding diluted nitric acid to the electrolyte. Nanowires of pure β-PbO 2 were obtained at pH 0.6, while mixed α-PbO 2 + β-PbΟ 2 nanowires were grown at pH 2. Pure α-phase was obtained in a bath containing lead acetate at pH 6.6. In all deposition conditions, nano…
Some aspects of formation and tribological properties of silver nanodumbbells.
2013
In this paper, metal nanodumbbells (NDs) formed by laser-induced melting of Ag nanowires (NWs) on an oxidized silicon substrate and their tribological properties are investigated. The mechanism of ND formation is proposed and illustrated with finite element method simulations. Tribological measurements consist in controllable real-time manipulation of NDs inside a scanning electron microscope (SEM) with simultaneous force registration. The geometry of NDs enables to distinguish between different types of motion, i.e. rolling, sliding and rotation. Real contact areas are calculated from the traces left after the displacement of NDs and compared to the contact areas predicted by the contact m…
Shifting the Photoresponse of ZnO Nanowires into the Visible Spectral Range by Surface Functionalization with Tailor-Made Carbon Nanodots
2018
We report on the surface functionalization of ZnO nanowires (NWs) with specifically synthesized carbon nanodots (C-dots, CDs) that allows us to shift the photoresponse of the NWs far into the visib...
Structural and electronic properties of InN nanowire network grown by vapor-liquid-solid method
2015
Growth of InN nanowires have been carried out on quartz substrates at different temperatures by vapor-liquid-solid (VLS) technique using different thicknesses of Au catalyst layer. It has been found that a narrow window of Au layer thickness and growth temperature leads to multi-nucleation, in which each site acts as the origin of several nanowires. In this multi-nucleation regime, several tens of micrometer long wires with diameter as small as 20 nm are found to grow along [ 11 2 ̄ 0 ] direction (a-plane) to form a dense network. Structural and electronic properties of these wires are studied. As grown nanowires show degenerate n-type behavior. Furthermore, x-ray photoemission study reveal…
Colloidal lithography and Metal-Organic Chemical Vapor Deposition process integration to fabricate ZnO nanohole arrays
2010
A complete set up of optimal process conditions for an effective colloidal lithography/catalyst assisted MOCVD process integration is presented. It mainly focuses on the determination of the deposition temperature threshold for ZnO Metal-Organic Chemical Vapour Deposition (MOCVD) as well as the concentration of metal-organic silver (Ag) catalyst. Indeed, the optimization of such process parameters allows to tailor the ZnO film morphology in order to make the colloidal lithography/catalyst assisted MOCVD approach a valuable bottom up method to fabricate bi-dimensional ordered ZnO nanohole arrays. (C) 2010 Elsevier B.V. All rights reserved.
High-density ZnO Nanowires as a Reversible Myogenic-Differentiation-Switch
2018
Mesoangioblasts are outstanding candidates for stem-cell therapy and are already being explored in clinical trials. However, a crucial challenge in regenerative medicine is the limited availability of undifferentiated myogenic progenitor cells because growth is typically accompanied by differentiation. Here reversible myogenic-differentiation switching during proliferation is achieved by functionalizing the glass substrate with high-density ZnO nanowires (NWs). Specifically, mesoangioblasts grown on ZnO NWs present a spherical viable undifferentiated cell state without lamellopodia formation during the entire observation time (8 days). Consistently, the myosin heavy chain, typically express…
Electron beam induced growth of silver nanowhiskers
2015
Abstract In this paper we report an electron beam induced rapid (up to several tens of nm/s) growth of silver nanowhiskers from silver nanowire networks coated with TiO 2 by sol–gel method. Different growth conditions are tested and it is demonstrated that growth is optimal for samples with the film thickness in the range 50–200 nm and previously annealed at 400 °C for 5–10 min. Growth mechanism is attributed to cooperative effect of several factors including diffusion of Ag into TiO 2 matrix during annealing, electromigration of Ag atoms caused by strong electric field, and presence of mechanical stresses at interfaces enhanced by thermal expansions due to local heating under e-beam illumi…
CuZnSnSe NANOTUBES AND NANOWIRES BY TEMPLATE ELECTROSYNTHESIS
2014
In this work we present some results of an extensive investigation aimed to find suitable conditions to grow CuZnSnSe (CZTSe) nanostructures through single-step electrodeposition into the channels of polycarbonate membranes. After the optimization of several electrodeposition parameters, we have found that pulsed current deposition, between 0 and -1 mA cm-2, is the best way to obtain CZTSe nanostructures mechanically attached to the support. An interesting result concerns the effect of supporting electrolyte in the deposition bath. In fact, changing its concentration it is possible to vary morphology of nanostructures from nanotubes to nanowires. In both case uniform arrays of ordered nanos…
Nanostructured Material Fabrication for Energy Conversion
2011
The electrochemical deposition is a suitable via to fabricate nanostructured materials for energy conversion, and for other purposes. This paper deals with the electrochemical synthesis of nanostructured alloys and ruthenium oxide, which can be used in Li-ion batteries and polymer electrolyte membrane electrolyzers.