Search results for "Thin film"

Porous Anodic Alumina proton conductors composites for H2/O2 thin film fuel cell

2009

Implementing the 3-omega technique for thermal conductivity measurements

2013

Thermal conductivity of the constituent materials is one of the most important properties affecting the performance of micro- and nanofabricated devices. These devices often make use of thin films with thicknesses ranging from some nanometers to few micrometers. The thermal conductivity of thin films can be measured with the three-omega method. In three-omega technique a metal wire acting as a resistive heater is microfabricated on the sample. Alternating current passing through the metal heater at a frequency ω heats the sample periodically and generates oscillations in the resistance of the metal line at a frequency 2ω. The oscillating resistance component is coupled with the driving curr…

Thin film conductivity measurements of carbon nanotube hemicellulose complex

2014

Työssä mitattiin hiilinanoputkista ja hemiselluloosasta koostuvan läpinäkyvän ohutkalvon sähkönjohtavuutta. Materiaali on Nemcel Oy:n kehittämä. Valmistimme useita näytteitä erilaisia mittauksia varten ja testataksemme eri valmistusmenetelmiä. Valmistetun ohutkalvon merkittävimmät ominaisuudet ovat läpinäkyvyys ja hyvä sähkönjohtavuus. Valmistetut kalvot olivat pääasiassa läpinäkyviä, mikä edellytti kalvon ohuutta. Itse materiaali toimitettiin vesiliuoksena, jossa oli 1:1 hiilinanoputkia ja hemiselluloosaa. Kalvot valmistettiin joko spinnaamalla tai kuivattamalla yksittäisiä pisaroita pinnalle. Näytteet valmistettiin pintaoksidioidulle piille, johon oli tehty kultaelektrodit. Kalvoa kuvatti…

Carbon nanotube derivatives for electro-optical active bulk heterojunctions

2012

Characterization of structural, optical and electric properties of TiO2 thin films prepared by reactive DC magnetron sputtering.

2007

International audience

Structural distortions in homoleptic (RE)4A (E = O, S, Se; A = C, Si, Ge, Sn): Implications for the CVD of tin sulfides

2001

The structures of Sn(SBut)4 and Sn(SCy)4 have been determined and adopt S4 and D2 conformations respectively; the anion [(PhS)Sn3]−, as its Ph4P+ salt, has a structure approaching Cs symmetry. In all three compounds, there are large variations in the ∠S–Sn–S within the same molecule, which have been rationalised in terms of the C–S–Sn–S–C conformations. For Sn(SR)4, the ∠S–Sn–S increases as the conformations change from trans, trans to trans, gauche and gauche, gauche, as the number of eclipsed lone pairs decreases and this rationale is shown to be applicable to a variety of A(ER)4 (A = C, Si, Ge, Sn; E = O, S, Se) and related [Mo(SR)4, Ga(SR)4−] systems. AM1 calculations have been used to …

Deposition of tin sulfide thin films from tin(iv) thiolate precursors

2001

AACVD (aerosol-assisted chemical vapour deposition) using (PhS)(4)Sn as precursor leads to the deposition of Sn3O4 in the absence of H2S and tin sulfides when H2S is used as co-reactant. At 450 degreesC the film deposited consists of mainly SnS2 while at 500 degreesC SnS is the dominant component. The mechanism of decomposition of (PhS)(4)Sn is discussed and the structure of the precursor presented.

Dirakův kužel a pseudogapped hustota stavů v topologické polovině Heuslerovy sloučeniny YPtBi

2016

Topologické izolátory (Tis) jsou zajímavé materiály, které vykazují nebývalé vlastnosti. . Zde jsme prozkoumali sloučeniny YPtBi jako příklad ze třídy polovu-Heuslerových materiálů. Topological insulators (TIs) are exciting materials, which exhibit unprecedented properties, such as helical spinmomentum locking, which leads to large torques for magnetic switching and highly efficient spin current detection. Here we explore the compound YPtBi, an example from the class of half-Heusler materials, for which the typical band inversion of topological insulators was predicted. We prepared this material as thin films by conventional cosputtering from elementary targets. By in situ time-of-flight mo…

Patterning of supported gold monolayers via chemical lift-off lithography

2017

The supported monolayer of Au that accompanies alkanethiolate molecules removed by polymer stamps during chemical lift-off lithography is a scarcely studied hybrid material. We show that these Au–alkanethiolate layers on poly(dimethylsiloxane) (PDMS) are transparent, functional, hybrid interfaces that can be patterned over nanometer, micrometer, and millimeter length scales. Unlike other ultrathin Au films and nanoparticles, lifted-off Au–alkanethiolate thin films lack a measurable optical signature. We therefore devised fabrication, characterization, and simulation strategies by which to interrogate the nanoscale structure, chemical functionality, stoichiometry, and spectral signature of t…

Kinetics of phase separation in thin films: Lattice versus continuum models for solid binary mixtures

2008

A description of phase separation kinetics for solid binary (A,B) mixtures in thin film geometry based on the Kawasaki spin-exchange kinetic Ising model is presented in a discrete lattice molecular field formulation. It is shown that the model describes the interplay of wetting layer formation and lateral phase separation, which leads to a characteristic domain size $\ell(t)$ in the directions parallel to the confining walls that grows according to the Lifshitz-Slyozov $t^{1/3}$ law with time $t$ after the quench. Near the critical point of the model, the description is shown to be equivalent to the standard treatments based on Ginzburg-Landau models. Unlike the latter, the present treatmen…