Thin films alumina

Most y-alumina powders placed under high vacuum and heated at moderate temperature (373-423 K) undergo complete water removal, and nearly all of the surface aluminum atoms are hydroxylated. Additionally, for hydroxylated alumina thin films prepared via aluminum evaporation/water oxidation cycles, although the surface density of OH groups would be the same as for powders, the specific surface area differs significantly [9]. 

Figure 16 Steady state CO2 production on (5.5 nm) Pd particles supported on an alumina thin film grown on NiAl( 1 1 0), as a function of Xqo and for various temperatures (Pco + Po2 — 1 x It)-6 mbar). (a) Experiment (b) micro-kinetic simulation (from Ref. [46]).

A study of dielectric characteristics of alumina thin films deposited on silicon substrates from Al(acac)3 dissolved in dmf by spray pyrolysis between 450 and 650 °C was recently reported by Falcony and coworkers. The addition of water vapor significantly improved the dielectric characteristics and smoothness of the deposits. In comparison to the CVD technique described above (see Section m.A.l) this procedure lead to considerable carbon impurities in the films. The overall resisfivify of fhe alumina layers decreases, when both the concentration of the solution and the deposition temperature increase, which is explainable with the increase of carbon residues in the films. 

Figure 15 Dissociation rate of CO on Rh (grown at 90 and 300 K) and Ir (grown at 300 K) clusters supported on ultrathin alumina thin films, measured by XPS. The level of dissociation on extended Rh (111) and (210) surfaces is indicated. (From M. Frank and M. Baumer [183].)...

Fig. 9.10. Permeation of a supported 7-alumina thin film for nitrogen and propylene at 263 K as a function of the relative pressure of propylene. After Uhlhom et al. [21,37].

Fig, 9.18. Permeation and separation factors of supported y-alumina thin film for nitrogen and propylene at 263 K (A,B). Propylene is the preferentially permeating component dashed line gives the relative pressure at which the maximum in the permeation of Fig. 9.18a. occurs. (C) and (D) as (A) md (B) but for a supported film modified with MgO. After Uhlhom et al. [37]. 

R. J.R, Uhlhorn, V.T. Zaspalis, K. Keizer and A.J. Burggraaf, Synthesis of ceramic membranes. Part II Modification of alumina thin films reservoir method. /. Mater. Sci., 27 (1992) 538-552. 

Schuetze A, Quinto DT (2003) Pulsed plasma-assisted PVD sputter-deposited alumina thin films. Surf Coat Technol 162(2-3) 174-182... 

Effects of Various Additives during Hot Water Treatment on the Formation of Alumina Thin Films for Superhydrophobic Surfaces... 

On the first step catalytic metals and materials with high ionic (or mixed ionic-electronic) conductivity are studied, for example, thin film of Pd, ultra thin films of Pt, Ir thick layers or bulk of hydrates of antimonic acid, Prussian Blue, beta-alumina, thin films of transition metal oxides etc. 

N. Nilius, M.V. Ganduglia-Pirovano, V. Brazdova, M. Kulawik, J. Sauer, H.J. Freund, Electronic properties and charge state of gold monomers and chains adsorbed on alumina thin films on NiAl(llO). Phys. Rev. B 81, 045422 (2010)... 

Tanaka et al. (43) observed efficient hole-burning activity in sol-gel alumina thin films, having in mind wiring applications of these materials. 

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