Search results for "thin film"

Slippage of water over hydrophobic surfaces

1999

When water is confined between hydrophobic surfaces, its flow properties are significantly different from those in bulk, or between hydrophilic surfaces. These changes (that are usually ignored) may be interpreted in terms of hydrophobic slippage. This chapter reviews recent developments in the hydrodynamics of water confined between solid hydrophobic surfaces, emphasizing the main experimental facts, theoretical models suggested, and different aspects of thin film drainage. The relevance of slippage in hydrophobic surface force measurements and on the coagulation rate of hydrophobic particles is discussed.

Multilayer Sequential Assembly of Thin Films That Display Room-Temperature Spin Crossover with Hysteresis

2006

Optical active centres in ZnO samples

2006

Abstract In recent years, there has been a resurgence in the interest in the use of ZnO (Eg ∼ 3.37 eV) as a material for a wide range of opto-emitter applications spanning visible and short wavelengths. Bulk, thin films and nanomaterials obtained using different synthesis methods have been investigated for optoelectronic and biotechnological device applications. Nominally undoped bulk samples typically present a myriad-structured near-band-edge recombination, mainly due to free/bound excitons and donor–acceptor pair transitions. Furthermore, deep level emission due to intrinsic defects and extrinsic impurities, such as transition metal ions, are commonly observed in different grades of bulk…

ZnO Nanoestructured Layers Processing with Morphology Control by Pulsed Electrodeposition

2011

The fabrication of nanostructured ZnO thin films is a critic process for a lot of applications of this semiconductor material. The final properties of this film depend fundamentally of the morphology of the sintered layer. In this paper a process is presented for the fabrication of ZnO nanostructured layers with morphology control by pulsed electrodeposition over ITO. Process optimization is achieved by pulsed electrodeposition and results are assessed after a careful characterization of both morphology and electrical properties. SEM is used for nucleation analysis on pulsed deposited samples. Optical properties like transmission spectra and Indirect Optical Band Gap are used to evaluate th…

Electrochemical Deposition Mechanism for ZnO Nanorods: Diffusion Coefficient and Growth Models

2011

Fabrication of nanostructured ZnO thin films is a critical process for many applications based on semiconductor devices. So on understanding of the electrochemical deposition mechanism is also fundamental for knowing the optimal conditions on growth of ZnO nanorods by electrodeposition. In this paper the electrochemical mechanism for ZnO nanorods formation is studied. Results are based on the evolution of the diffusion coefficient using the Cotrell equation, and different growth models proposed by Scharifcker and Hills for nucleation and growth.

New Cost Effective Titanium Based Protective and Decorative Coatings by Ion Plating Plasma Assisted IPPA

2009

The activity aiming to replace galvanic treatments by vacuum processes is based on the effort to reduce the production costs and to set-up new decorative effects impossible to be galvanically realised because the use of dielectric materials. This work describes cost effective metal-oxide and oxide-metal-oxide decorative coatings based on the use of titanium as basic material deposited by Ion Plating Plasma Assisted from Reactive Magnetron Sputtering source. A new multilayer protective and decorative structure, based on the use of titanium and titanium oxides is also presented. The protective effect against aggressive environment is obtained by alternating layers of metal and metal-oxide mix…

Current injection from metal to MoS2 probed at nanoscale by conductive atomic force microscopy

2016

Contacts with MoS2 are currently the object of many investigations, since current injection through metal/MoS2 interfaces represents one of the limiting factors to the performance of MoS2 thin film transistors. In this paper, we employed conductive atomic force microscopy (CAFM) to investigate the current injection mechanisms from a nanometric contact (a Pt coated tip) to the surface of MoS2 thin films exfoliated on SiO2. The analysis of local current-voltage (I-V) characteristics on a large array of tip positions provided high spatial resolution information on the lateral homogeneity of the tip/MoS2 Schottky barrier Phi(B) and of the ideality factor n. From the histograms of the measured P…

Carbon Nanotubes: In-Situ Growth of Ultrathin Films of NiFe-LDHs: Towards a Hierarchical Synthesis of Bamboo-Like Carbon Nanotubes (Adv. Mater. Inter…

2014

Influence of irradiation on the switching behavior in PZT thin films

2005

Spatially nonuniform imprint behavior induced by X-ray synchrotron, electron and neutron irradiation has been investigated in sol–gel Pb(Zr,Ti)O3 thin films. The analysis of the switching current data reveals the strong influence of irradiation on the switching current shape. The obtained effects have been explained as a result of acceleration of the bulk screening process induced by irradiation. It was shown that the spatial distribution of the internal bias field is determined by the domain structure existing during irradiation. The changes in the structural characteristics during fatigue cycling have been reveled by high resolution synchrotron X-ray diffraction experiments on (1 1 1)-ori…

InN thin film lattice dynamics by grazing incidence inelastic x-ray scattering.

2011

Achieving comprehensive information on thin film lattice dynamics so far has eluded well established spectroscopic techniques. We demonstrate here the novel application of grazing incidence inelastic x-ray scattering combined with ab initio calculations to determine the complete elastic stiffness tensor, the acoustic and low-energy optic phonon dispersion relations of thin wurtzite indium nitride films. Indium nitride is an especially relevant example, due to the technological interest for optoelectronic and solar cell applications in combination with other group III nitrides.