Dependence on film thickness

The dependence on film thickness is attributed to the dewetting nucleation, which occurs in the 2.5-4.5 nm thickness range via the formation of randomly distributed droplets rather than the formation of holes. When the initial film thickness exceeds 4.5 nm, dewetting is trigged via nucleation of holes instead of droplets, and for film thickness above 10 nm, dewetting develops slowly via hole nucleation at defects. The different dewetting processes observed for different initial film thicknesses can be explained in terms of the variation of disjoining pressure and the inability of the polymer to spread on its own monolayer. 

Using this equation, the flow of the reaction was followed by registering the frequency shift as a function of reaction time. Typical dependencies are shown in Figure 38 (Facci et al. 1994). As one can see, the curves tend to come to saturation (saturation time depends on film thickness). On the other hand, the plateau level in all cases corresponds well to the value resulting from simple calculation of the number of cadmium atoms available for the reaction in each sample. Numerical data of such estimates are presented in Table 8. The available amount of cadmium atoms was estimated in this case, taking into ac-... 

Real-time mass increases of MBe (M = Cd, Hg) films on a QCM have been measured as a function of H2S exposure time (58,64). The results from one of the studies, presented in Figure 3.5.13 (58), show the mass increase reached at equilibrium was proportional to film thickness and corresponded to 83-88% conversion of Cd2+ ions to CdS. The rate at which equilibrium was reached was strongly dependent on film thickness, in contradiction to the results presented in Figure 3.5.10 (46). 

The thiosulphate mercury(ll) complex in ammoniacal solution has also been used to deposit films of HgS, both in ammoniacal and nonammoniacal solutions. The deposit from the former was predominantly a-HgS (cinnabar). As with the previous films, a sharp optical absorption onset at ca. 400 nm was observed, together with a more gradual one extending, in this case, to beyond 800 nm and dependent on film thickness. The nonammoniacal solution gave crystal sizes (and optical bandgaps) that varied with deposition temperature from 3 nm (2.4 eV) at 0°C to 8 nm (1.9 eV) at 85°C and corresponding resistivities between 10" and 10 O-cm. 

PTFE sheets have the highest efficiency. Increasing Ti02 content is veiy effective for improving the performance. The efficiency of the painted films depends on film thickness and the amount of Ti02. 

There is also evidence that film stress depends on film thickness, although there are conflicting reports. Therefore, it is prudent to measure stress using films equal in thickness to those eventually to be used. For very thin films and small stresses, quite small deflections may have to be measured. 

Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness, Adv. Mater. 2003, 15, 1435-1438. 

Poly (vinyl alcohol)/Water. When distilled water is poured onto the surface of poly (vinyl alcohol) films dried onto the impedometer bar, the initial response is not the expected decrease in stiffness caused by the solvating effect of the water, but rather a marked increase in stiffness followed by a slow relaxation as shown in Figure 2. (The A db scale on this and most following graphs has been adjusted to read as change in A db from the initial value. Thus, the zero point is for the dried polymer film. The absolute value A db for dried polymer films ranged from 1 to 16 A db depending on film thickness and polymer type.)... 

Several authors [25,29-32] believe that film elasticity is an important factor for film and foam stability. However, an immediate relation between foam stability and film elasticity has not been established but if it exists, it should not be directly proportional. Even at large values of elasticity modulus the insoluble surfactant monolayer are poor film stabilisers. The modulus of elasticity of such films does not depend on film thickness and, therefore, it can be... 

The basic mechanism of foam degradation in porous medium is film coalescence. It depends on film thickness and capillary pressure. In the process of advancement the film thickness changes considerably thickens in the narrow parts (pore throats) and thins in the wider parts (pore bodies). Visual observations of such a stretching-squeezing mechanism are reported by Huh et al. [178]. Therefore, the film thickness would depend on the liquid/gas ratio, the rate of movement and the ratio of pore-body to pore-throat. When the critical capillary (disjoining) pressure is reached, the film will rupture. 

Even though these transitions are different in many ways, as demonstrated below, the way in which acoustic energy interacts with polymeric materials permits us to use AW devices to probe changes in polymer film viscoelastic properties associated with these transitions. It should be emphasized up front, however, that evaluating the viscoelastic properties (e.g., modulus values) requires an ability to effectively model the film displacement profiles in the viscoelastic layer. As described in Section 3.1.8, the film displacement effects are dictated by the phase shift, , across the film. Since depends on film thickness, perturbations in acoustic wave properties due to changes in viscoelastic properties (e.g., during polymer transitions) do not typically depend simply on the intrinsic polymer properties. This can lead to erroneous predictions if the film... 

Pesavento, P.V. et al., Film and contact resistance in pentacene thin-film transistors Dependence on film thickness, electrode geometry, and correlation with hole mobility,... 

Since alkali diffusion from a substrate into a crystallizing film requires time, the influence on the resulting structure type decreases from substrate/film boundary to film/air boundary depending on film thickness d. Thus, thin 2 films deposited on alkali glasses exhibit lower mean refractive indices n than thicker films. This effect is shown in Fig. 5 for 2 films made from butyl titanate solution and baked 1 h at 450°C and 500°C respectively [28]. The refractive index of 2 layers fabricated in this way is dependent on various production parameters it is clear... 

Do the electronic properties depend on film thickness and morphology ... 

The fluorescence of thin films of 30b depends on film thickness, and in thick films the main emission is shifted from 463 to 497 nm. The reason for this behavior is exciplex formation of naphthalene units in neighboring PPE chains. 

Gomez, R, and P, Salvador, Photovoltage dependence on film thickness and type of illumination in nanoporous thin film electrodes according to a simple diffusion model. Solar Energy Materials and Solar Cells, 2005, 88(4) pp, 377-388... 

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