The effect of point defects, dislocations and grain boundaries on the electron scattering in molybdenum thin films having a constant thickness of 500nm was described quantitatively in form of a ...dependence of the electrical resistivity on the concentration of impurity atoms, stress-free lattice parameter, microstrain and grain size. The concentration of impurity atoms and the dislocation density were modified by depositing the Mo thin films using different techniques (DC magnetron sputtering, pulsed DC magnetron sputtering and RF magnetron sputtering) and by varying the substrate temperature (25°C, 150°C, 250°C and 350°C). As expected, the electrical resistivity of the Mo films decreased with decreasing density of microstructure defects. For all deposition methods, the dislocation density decreased with increasing substrate temperature, which led to an overall decrease of the measured resistivity with increasing substrate temperature. Due to the deposition equipment constraints during the RF sputtering, up to 3at.% of Fe, Cr and Ni were incorporated at the regular lattice positions in the crystal structure of molybdenum, which increased the resistivity of the Mo films nearly two times as compared to the DC and pulsed DC sputtered films.
► Effect of impurity atoms and dislocations on the resistivity of Mo was quantified. ► Dislocation density decreased with increasing deposition temperature. ► Impurity atoms occupied both regular and interstitial lattice positions. ► Impact of impurities located at regular and interstitial positions was different.
In this study we report on the deposition of Pt nanocluster films prepared by gas aggregation source that was operated with argon as working gas. The aim of this study was optimization of deposition ...process as well as determination of properties of deposited nanocluster films and their temporal stability. It was found that the production of Pt nanoclusters reached maximum value for pressure of 100Pa and increases monotonously with magnetron current. The deposition rate at optimized deposition conditions was 0.7nm of the Pt nanocluster film per second. Deposited films were porous and composed of 4nm Pt nanoclusters. The nanoclusters were metallic and no sights of their oxidation were observed after 1year on open air as witnessed by X-ray photoelectron spectroscopy. Regarding the electrical properties, a dramatic decrease of the resistivity was observed with increasing amount of deposited nanoclusters. This decrease saturated for the films approximately 50nm thick. Such behavior indicates transition between different mechanisms of electrical conductivity: charge hopping for thin discontinuous films and current conduction through conducting path formed when higher amount of nanoclusters is deposited. Different mechanisms of electrical conduction for thin and thick layers of Pt were confirmed by subsequent investigation of temperature dependence of resistivity. In addition, no changes in resistivity were observed after one year on open air that confirms stability of produced Pt nanocluster films.
•Pt nanocluster films were deposited by gas aggregation nanocluster source.•Conditions leading to effective deposition of Pt nanocluster films were found.•Deposited nanocluster films have good temporal stability.•Electrical properties of Pt films were found to depend on their thickness.
The preparation of thin oxide films on metal supports is a versatile approach to explore the properties of oxide materials that are otherwise inaccessible to most surface science techniques due to ...their insulating nature. Although substantial progress has been made in the characterization of oxide surfaces with spatially averaging techniques, a local view is often essential to provide comprehensive understanding of such systems. The scanning tunneling microscope (STM) is a powerful tool to obtain atomic-scale information on the growth behavior of oxide films, the resulting surface morphology and defect structure. Furthermore, the binding configuration and spatial distribution of adsorbates on the oxide surface, as well as their electronic and optical properties can be probed with the STM and embedded spectroscopic techniques.
This article surveys state-of-the-art STM experiments aiming for an investigation of surface properties of oxide materials as well as their interaction with individual adatoms, molecules and metal particles. It provides an introduction into the nucleation and growth of oxide layers on single-crystalline metal substrates, putting special emphasis on the various relaxation mechanisms of the oxide lattice to release the misfit strain with the support. Additionally, the peculiarities of polar oxide films are discussed. In the second part, the different interaction schemes between oxide surfaces and adsorbates are presented from the theoretical point of view as well as on the basis of the key experiment performed with the STM. The focus lies hereby on charge-mediated binding schemes, leading to the formation of cationic or anionic species on the oxide surface. Furthermore, the role of point and line defects in the oxide adsorption behavior is inferred. The potential of thin oxide films as systems with tunable physical and chemical properties is highlighted at the end of this review.
Superhydrophobic wood has been created using a combination of O2 plasma etching and plasma deposition of thin films to achieve the necessary combination of surface roughness and chemistry. Inherently ...hydrophobic fluorocarbon films (from pentafluoroethane (PFE) precursor) and hydrophilic diamond-like carbon (DLC) coatings (from acetylene precursor) were both used to create highly water repellent substrates. The effect of O2 plasma etching on surface roughness was investigated using Scanning Electron Microscopy (SEM) and Laser Scanning Confocal Microscope (LSCM) profilometry. The wetting behavior of the resulting wood was determined by static water contact angle and droplet sliding angle measurements. Wood samples subjected to O2 plasma etching prior to fluorocarbon deposition exhibited “roll-off” superhydrophobicity with low sliding angles; the sample in this study with the most extreme wetting properties has the highest water contact angle and lowest sliding angle reported to date for modified wood substrates (WCA 161.2°±1.5° and sliding angle ~15°), without affecting visual appearance of the wood. Due to our ability to control roughness, etched samples that were coated with hydrophilic DLC films displayed superhydrophobic behavior (WCA), although the surface was “sticky” in that water droplets did not slide or dislodge from vertically-held substrates.
•Superhydrophobic wood surfaces created by plasma etching and plasma film deposition.•Wood roughness from plasma etching established water droplet repellency and adhesion.•Etched wood samples with fluorocarbon film exhibited “roll-off” superhydrophobicity.•Etched wood samples with amorphous carbon film was superhydrophobic but “sticky”.
When Ridley Scott envisioned Blade Runner 's set as "Hong Kong on a bad day," he nodded to the city's overcrowding as well as its widespread use of surveillance. But while Scott brought Hong Kong and ...surveillance into the global film repertoire, the city's own cinema has remained outside of the global surveillance discussion. In Arresting Cinema, Karen Fang delivers a unifying account of Hong Kong cinema that draws upon its renowned crime films and other unique genres to demonstrate Hong Kong's view of surveillance. She argues that Hong Kong's films display a tolerance of—and even opportunism towards—the soft cage of constant observation, unlike the fearful view prevalent in the West. However, many surveillance cinema studies focus solely on European and Hollywood films, discounting other artistic traditions and industrial circumstances. Hong Kong's films show a more crowded, increasingly economically stratified, and postnational world that nevertheless offers an aura of hopeful futurity. Only by exploring Hong Kong surveillance film can we begin to shape a truly global understanding of Hitchcock's "rear window ethics."
The growing demand of flexible electronic devices is increasing the requirements of their power sources. The effect of bending in thin-film batteries is still not well understood. Here, we ...successfully developed a high active area flexible all-solid-state battery as a model system that consists of thin-film layers of Li
4
Ti
5
O
12
, LiPON, and Lithium deposited on a novel flexible ceramic substrate. A systematic study on the bending state and performance of the battery is presented. The battery withstands bending radii of at least 14 mm achieving 70% of the theoretical capacity. Here, we reveal that convex bending has a positive effect on battery capacity showing an average increase of 5.5%, whereas concave bending decreases the capacity by 4% in contrast with recent studies. We show that the change in capacity upon bending may well be associated to the Li-ion diffusion kinetic change through the electrode when different external forces are applied. Finally, an encapsulation scheme is presented allowing sufficient bending of the device and operation for at least 500 cycles in air. The results are meant to improve the understanding of the phenomena present in thin-film batteries while undergoing bending rather than showing improvements in battery performance and lifetime.
SnS films with thicknesses of 20–65
nm have been deposited on glass substrates by thermal evaporation. The physical properties of the films were investigated using X-ray diffraction (XRD), scanning ...electron microscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and ultraviolet–visible-near infrared spectroscopy at room temperature. The results from XRD, XPS and Raman spectroscopy analyses indicate that the deposited films mainly exhibit SnS phase, but they may contain a tiny amount of Sn
2S
3. The deposited SnS films are pinhole free, smooth and strongly adherent to the surfaces of the substrates. The color of the SnS films changes from pale yellow to brown with the increase of the film thickness from 20
nm to 65
nm. The very smooth surfaces of the thin films result in their high reflectance. The direct bandgap of the films is between 2.15
eV and 2.28
eV which is much larger than 1.3
eV of bulk SnS, this is deserving to be investigated further.
The mechanisms of corrosion and wear improvements by low energy high current pulsed electron beam (LEHCPEB) have been investigated for an AISI 316
L steel. Selective purification followed by ...epitaxial growth occurred in the top surface melted layer (2–3
μm thick) that was softened by tensile stresses and, to a much lower extent, by lower efficiency of MnS precipitation hardening. Electrochemical impedance spectroscopy and potentiodynamic polarization analyses used to model the corrosion behavior revealed that, while craters initiated at MnS inclusions initially served as pitting sites, the resistance was increased by 3 orders of magnitude after sufficient number of pulses by the formation of a homogeneous covering layer. The wear resistance was effectively improved by sub-surface (over 100
μm) work hardening associated with the combine effect of the quasi-static thermal stress and the thermal stress waves. The overall results demonstrate the potential of the LEHCPEB technique for improving concomitantly the corrosion and wear performances of metallic materials.
The structural and electrical properties of chemical-solution-deposited Bi1−xSmxFeO3 (x=0, 0.025, 0.05, 0.075, 0.1) thin films on Pt/Ti/SiOx/Si (100) substrates were investigated. Films up to 5at.% ...Sm exhibited a single perovskite phase with rhombohedral structure, whereas films with 7.5 and 10at.% Sm exhibited a distorted orthorhombic crystal structure. Atomic force microscopy of the films showed homogeneous and smooth surface. Films with 7.5at.% Sm exhibited significant reduction in leakage current in the high electric field region and improved breakdown characteristic. The polarization vs. electric field (P–E) hysteresis loops were recorded in a 100nm thick film with 3V coercive voltages. Moreover, well saturated P–E hysteresis loops with high polarization (80μC/cm2) and low coercive field (300kV/cm) were also recorded in 100nm thick films with low coercive voltage (5V). The Sm-substitution in BiFeO3 improved the fatigue endurance with no significant degradation in polarization even after 108 fatigue cycles. These results demonstrate that Sm-substituted BifeO3 films have potential for application in low voltage operational device.
► The electrical properties of Sm-substituted BiFeO3 thin films are investigated. ► Leakage current reduced and improved breakdown characteristic. ► Polarization-electric field hysteresis loops recorded with 3V coercive voltages. ► Improved fatigue endurance with no significant degradation in Pr after 108cycles. ► These films have potential for applications in low voltage operational devices.
Cinema and Colour: The Saturated Image is a major new critical study of the use of colour in cinema. Using the dialectic of colour and monochrome as a starting point, Paul Coates explores the ...symbolic meanings that colour bears in different cultures, and engages with a range of critical approaches to filmic colour, building on the work of such theorists as Sergei Eisenstein, Rudolf Arnheim and Stanley Cavell. Coates also provides close analyses of films by directors such as Antonioni, Bergman, Godard, Hitchcock, Hou Hsiao-Hsien, Sirk, Kieslowski, Tarkovsky, Von Trier and Zhang Yimou. Coates' focus is on films that deliberately exploit the rich multiplicity of cultural meanings and associations ascribed to colour, including All That Heaven Allows, Deux ou trois choses que je sais d'elle, The Double Life of Véronique, The Flight of the Red Balloon, Red Desert, Schindler's List, Silent Light, Solaris, The Three Colours Trilogy and The Wizard of Oz.
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