Zirconia films

Thin sol gel ORMOSIL-zirconia films successfully inhibit magnesium corrosion (Figure 4.11). The film obtained by combining sol-gel monomers phenyltrimethoxysilane (PTMOS) and zirconium(iv) tetra-1-propoxide (ZrTPO) exhibits superior corrosion inhibition as compared with other films,13 while the ZrTPO-based film alone does not show significant corrosion inhibition, and the PTMOS-based film provides only moderate protection. The films are prepared by the traditional acid-or base-catalysed hydrolysis and condensation, depositing first the PTMOS film followed by the ZrTPO-based film. 

Therefore, the Si(001) surface covered with ZrCT groups between dimer rows was taken as the initial structure for the simulation of zirconia film growth. The following set of chemical reactions was used as kinetic mech-... 

The proposed kinetic mechanism was used to model zirconia film growth in the ALD process in the framework of the KMC-DR method. The structures of the zirconia film after first, second, third, and fourth ALD cycles are... 

The simplest way to enhance the overall conductance is to decrease the electrolyte thickness, and there are many attempts to employ zirconia films of a few pm or even thinner ones. This... 

Similarly, CdS NCs capped with mercaptopro-pyltrimethoxysilane (MPTMS) were added to alcohohc solutions of TEOS or TMOS and subsequently incorporated into sihca matrices. Pb and Hg-based NCs have also been synthesized with MPTMS as the capping agent, and the role of the pendant siloxy groups is again to anchor the NCs to the sihca, silica-titania, or zirconia networks. Zirconia films doped with PbS NCs were prepared with refractive indices up to 1.53 and a third-order susceptibility value of 1.3 X 10 esu. Higher refractive index sihca-titania sol gel films doped with PbS (n = 1.63) were also fabricated. ... 

Zr(tmnd)4 (30) and Zr(tod)4 (31) have also been found to be suitable precursors for the deposition of monoclinic zirconia. Both species possess high deposition rates in the temperature range of 500-750 °C but, as discussed earlier for fluorine-free zirconium tetra-enolates, the disadvantage is the high carbon content of the appropriate zirconia films (i.e. 30 7-8 at%)3w. 

FIGURE 20. SEM images of the microstracture of zirconia films deposited from Zr(acac)2(OCH-(CF3)2)2 at different temperatures (top cross-section of film, bottom detail of microstructure left 500°C, middle 550°C, right 600°C) ". Reproduced from Reference 311 by permission of Wiley-VCH... 

Electrochemical vapor deposition has been explored for making gas-tight, dense, solid electrolyte films on porous substrates, - and the most smdied system has been the yttria-stabilized zirconia films on porous alumina substrates for solid... 

The experimental observation that there exists a critical thickness above which cracking occurs cannot easily be explained. Brinker [1] discusses a theory which explains that very thin layers can bear much larger stresses because critical cracks carmot be formed unless a certain critical thickness is surpassed. This thickness is estimated to be equal to or less than 1 pm and Brinker comes to the conclusion that thicker films will always crack. This is certainly not the case for alumina, titania and zirconia films for which much larger (alumina) to larger (titania) thicknesses are observed. As shown in Table 8.2 critical thicknesses of a few pm in single-step dip-coated films occur and critical flaws are smaller than this thickness and so can be present. 

An experimental illustration of the study of such objects, made of several polyciystalline films, is shown in Figure 7.7. We reahzed a sample comprised of a titaniirm oxide film placed on top of a zirconia film, all of this deposited on a sapphire substrate. The titaniirm oxide film is roughly 20 run wide and the zirconia film about 50 run wide. Two diffraction patterns obtained with the incidence angles... 

Figure 7.7. Influence of the incident X-ray beam s incidence angle on the dijfraction pattern of a sample comprised of a titanium oxide film and a zirconia film, deposited on a sapphire substrate...

Figure 7.16. Stucfy of an epitaxial zirconia film on a single crystal magnesia substrate [GUI 98, GUI 99]...

The samples studied in this section are zirconia films deposited on sapphire substrates. These films are produced by using a sol-gel method based on a dipping process which we have already described. After drying the sample and firing it at a low-temperature, we get a polycrystalline film comprised of randomly oriented nanocrystals (see section 7.2.1). A high temperature process, in this case, lasting one hour at 1,500°C, would yield a set of epitaxial islands of zirconia (see sectiorts... 

Figure 7.30. Reciprocal lattice maps of the zirconia film s (200) and (400) reciprocal lattice nodes...

Figure 7.34. Observation by in plane-view optical microscopy of the zirconia film...

Chang, J.T. et al.. Deposition of yttria-stabilized zirconia films using arc ion plating. Surf. Coat. Techn. 200 (2005) 1401-1406. 

In contrast, an EXAFS analysis from amorphous zirconia films of nominal Zr02 composition, as opposed to a hydroxide composition, found that the local structure in amorphous Zr02 can be described by an eightfold Zr-0 shell widely spread between 0.19 and 0.32nm with a distinct peak at 0.216nm consisting of four oxygen nearest... 

Zirconia (ZrCh) thin films were grown by MOCVD on silicon, whereby temperature and pressure were varied from 700 to 900 °C and from 100 to 2000 Pa, respectively [262]. The oxide films were characterized by field emission microscopy and X-ray diffraction. The characteristics of silicon were not modified by the presence of a thin film of silicon oxide (10 nm), formed in the reactor during heating. The zirconia films were found to adhere well. 

P. Stefanov, D. Stoychev, I. Valov, A. Kakanakova-Georgieva, T. Marinova, Electrochemical deposition of thin zirconia films on stainless steel 316 L, Mater. Chem. Phys. 65 (2000) 222. 

G. Tyuliev, D. Panayotov, I. Avramova, D. Stoichev, T. Marinova, Thin-film coating of Cu-Co oxide catalyst on lanthana/zirconia films electrodeposited on stainless steel, Mater. Sci. Eng. C-Biomim. Supramol. Syst. 23 (2003) 117. 

R. Tu, T. Kimura and T. Goto, Rapid Synthesis of Yttria-Partially-Stabilized Zirconia Films by Metal-Organic Chemical Vapor Deposition, Mater. Trans., 43, 2354-2356 (2002). 

J. A. Belot, R. J. McNeely, A. Wang, C. J. Reedy and T. J. Marks, Expedient route to volatile zirconium metal-organic chemical vapor deposition precursors using amide synthons and implementation in yttria-stabilized zirconia film growth,-/. Mater. Res., 4, 12-15,(1999). 

T. Kimura and T. Goto, Thermal conductivities of yttria-stabilized zirconia films measured by a laser-heating AC method. Surf. Coat. Tech., 198, 129-132 (2005). 

Wang, X. Atkinson, A. Microstructure evolution in thin zirconia films Experimental observation and modelling. Acta Materialia 59,2514-2525 (2011). 

Fedrizzi L, Rodriguez FJ, Rossi S, Deflorian F, Di Maggio R (2001) The use of electrochemical techniques to study the corrosion behaviour of organic coatings on steel pretreated with sol-gel zirconia films. Electrochim Acta 46(24—25) 3715-3724... 

Pal UB, Singhal SC (1990) Electrochemieal vapor deposition of Yttria-Stabilized Zirconia films. J Electrochem Soc 137 2937-2941... 

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