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Showing 1 to 20 of 30 for “"critical thickness"”.
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Critical thickness in silicone thermosets
Critical thickness effects are utilized to achieve high fracture toughness in brittle polymers. The postulate of critical thickness, which is: "Macroscopically brittle polymers deform in a ductile fashion below a critical dimension" is validated for silicone thermosets and polystyrene using novel …
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Critical thickness in silicone resin
The critical thickness at which a toughness transition occurs in a polymer was determined for the Dow Corning 4-3136 silicone resin. 4-3136 is macroscopically brittle, but becomes up to ten times more ductile when it is processed in the form of a sufficiently thin film. Thickness was controlled for …
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Increasing the Critical Thickness of InGaAs Quantum Wells Using Strain-Relief Technologies
Compliant membranes enable strain relief by depositing on an ultra-thin semiconductor base. Unlike growth on typical thick substrates, expansion of the compliant membrane during strained-layer regrowth allows the membrane to accommodate most of the strain energy. Ternary InGaAs compliant films …
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Limited-area growth of Ge and SiGe on Si
… specifically the effect of growth area on the critical thickness. The critical thickness of Sio.33Geo.67 formed by selective epitaxial growth in areas of 2.3 x 2.3 [mu]m was found to be 8.5 nm, which is an increase of 2x compared to the critical thickness observed for growth in large areas …
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Characterization of III-V compound semiconductor heterostructures grown by metalorganic chemical vapor deposition
… produce high quality samples with uniform layer thickness, no defects, and abrupt interfaces. For this metalorganic chemical vapor deposition (MOCVD) is one of the most important growth methods. In this study, transmission electron microscopy (TEM) was used for the characterization of epilayer …
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Optical properties of ultra-thin niobium nitride films for single photon detectors
… optical properties of NbN films appear to have a critical thickness above which the optical parameters stabilize. I also found that the deposition process has better stability over time for thicker films than for thinner ones; that is, when films are deposited weeks apart, the thinner films show …
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The role of cold supraglacial volcanic deposits in influencing glacial ablation
… can have both positive and negative effects. A critical thickness exists at which sub-debris ablation is equal to that of bare ice; debris will hinder ablation if it exceeds this thickness, and enhance it if its thickness is lower. The value of the critical thickness depends on various factors, …
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Strain relaxation mechanism of semiconductor thin films
… to introduce misfit dislocations above a certain thickness of film growth, which is called a critical thickness. In this case, strain is considered in the continuum elastic sense, defined by the lattice constant of the material. From measurement of the positions of multiple Bragg reflections, …
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Multi-scale modelling of III-nitrides: from dislocations to the electronic structure
… atomistic level modelling for the case of the critical thickness of thin epitaxial layers, and covers some issues of simulating the electronic structure of III-nitride alloys by means of the first principle methods. The first part of this work discusses several topics involving dislocation …
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The role of accessory minerals in inhibiting bentonite erosion in the geological disposal of higher activity radioactive waste
… at the extrusion / groundwater interface at a critical thickness. Irrespective of whether a variable or planar aperture fracture was used. Aperture variability plays a role in that, after deposition of the minerals at a critical thickness and subsequent decrease in mass loss from the system, …
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Buckling of an equatorial segment of a spherical shell loaded by its own weight
… own weight. Plots are presented which compare a critical thickness parameter with the results of an elementary approach. The elementary approach assumes that the shell will buckle if the maximum compressive stress is greater than the critical compressive stress for a complete sphere loaded by …
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Estudo do comportamento de lastros de materiais granulares sobre estacas com capitéis através de modelos reduzidos
… evaluated with the aid of a small scale model: critical thickness of the base in relation to pile spacing and cap diameter, density and grain size distribuition of the granular material, external pressure, and two - and three - dimensional effects. The behaviour observed in the model were …
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Electrochemical Investigation of Thin Nickel, Copper and Silver Films Interfaced with Yttria-Stabilized Zirconia
… evaporative physical vapor deposition (PVD). The critical thickness of copper, silver and nickel thin films were foundusing in-situ resistance measurements. Following this, 50 and 100 nm copper and nickel films were studied using solid electrolyte cyclic voltammetry (SECV) to determine their …
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Impurity-induced layer disordering of quantum well heterostructures by silicon diffusion from aluminum-reduced silicon dioxide and silicon nitride
… x}$Ga$\sb{\rm 1-x}$As quantum well (QW) near critical thickness is examined under high-power, continuous-wave (cw) laser operation in a 10-stripe array fabricated via hydrogenation.
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Experimental determination of cell adhesion and proliferation response to substrata thickness
… study of the effect of varying substrata thickness, and its correlation to a substratum's effective stiffness that a cell feels. Furthermore, there have been differing views on what the critical thickness of a substrate is, above which there will be no difference in cell behavior. An …
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Strained SiGe-channel p-MOSFETs : impact of heterostructure design and process technology
… of heterostructure composition and SiGe channel thickness on mobility and MOSFET off-state leakage, as well as critical thickness and thermal budget constraints. In particular, the impact of the strained channel thickness on mobility is analyzed in detail. This work provides a detailed analysis …
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Wave-induced liquefaction processes in marine sediments
… of liquefied soil viscosity and density. The thickness of seabed is also found to affect liquefaction but the trend is not monotonic. There seems to be a critical seabed thickness, at which the effect of seabed thickness on liquefaction reverses. Below the critical thickness, the liquefaction …
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Integration of III-V optical devices and interconnects on Si using SiGe virtual substrates
… arrays can form in GaAs layers grown over a critical thickness after a temperature change. These cracks can act as electrical shorting paths and can also limit the usable area for device fabrication, and therefore need to be eliminated.
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Development of large-scale colloidal crystallisation methods for the production of photonic crystals
… drying stage. These films are crack-free up to a critical thickness, and show very large domains, which are visible in low magnification SEM images as Moiré fringe patterns. Higher magnification reveals separation between alternate fringe patterns are domain boundaries between individual …
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Multiscale Mechanics of Graphene Oxide and Graphene Based Composite Films
… of graphene-TiO2 composites. It was found that a critical thickness range of TiO2 deposition on graphene is required for the observed stiffness enhancement effect of graphene to influence the mechanical behavior of the composite.
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