Mixed oxide films

The deliberate growth of tin oxide or mixed oxide films in both acid and alkaline solutions has been reviewed recently . The effect of additions to alkaline solutions on their attack on tin has been considered as has the tendency for pitting corrosion to occur in solutions containing chloride ions" . In connection with this, potential pH diagrams for Sn-H O-Cl systems have been published . 

Mixed-oxide photoelectrodes composed of two different kinds of singleoxide semiconductor materials are also investigated. Tennakone and co-workers reported that the DSSC composed of a nanocrystalline Sn02/Zn0 mixed photoelectrode with N3 dye revealed a high efficiency, which was almost equal to that of the Ti02 solar cell [94,95] that is, rj = 7.94% (Jsc = 22.8 mA/cm2, Voc = 0.67 V, and ff = 0.50) under 80 mW/cm2 and r] = 15% under 10 mW/cm2 [94]. They employed a mixed-oxide film consisting of small particles of Sn02 (15 nm)... 

The technologically important dimensionally stable anodes (DSA) are thermally prepared mixed oxide films supported on an inert substrate, usually Ti, which contain Ru02 as the catalytically active component. These anodes exhibit high performance in the industrial generation of chlorine. 

Rende, D. Schwarz, K. Rabe, U. Maier, W. F. Arnold, W., Combinatorial synthesis of thin mixed oxide films and automated study of their piezoelectric properties, Prog. Solid State Chem. 2004, 223, 245-248... 

From the various possibilities of forming mixed oxide films, for example to obtain special refractive indices, only a few are used. Polymeric structures like silicate glass films can also be made at fairly low temperatures. 

Figure 35.4. Schematic pathway to mesostructured silica / titania mixed oxide films.

The actual surface and in-depth composition of the mixed oxide films (Ti02)o 6(Ta205)o 2 treated at 200°C and 800°C was studied by XPS. Figure 3.13 shows the survey spectra of the rutile film (Ti02)o6(Ta205)o.2 treated at 200°C (a) and at 800°C (b) after 30 min of sputtering, which demonstrates the presence of Ti and Ta for both films. 

Lasagni A, Seyler M, Holzapfel C, Maier W, Miicklich F. (2005) Periodical gratings in mixed-oxide films by laser-interference irradiation. Adv Mater 17 2228—2232. 

In the mechanism described by Rosenfeld et al. [91], CrO/ groups are adsorbed onto the steel surface, where they are reduced to trivalent ions. These trivalent ions participate in the formation of the complex compound FeCr20,4 (0H ) , which in turn forms a protective film. Largin and Rosenfeld have proposed that chromates do not merely form a mixed oxide film at the metal surface instead, they cause a change in the structure of the existing oxide film, accompanied by a considerable increase in the bond energy between the iron and oxygen atoms. This leads to an increase in the protective properties of the film [92],... 

It should perhaps also be noted that several workers in the field describe the protection mechanism more simply as the formation of a normal protective mixed oxide film, with defects in the film plugged by Cr203 [23,57]. 

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