Ceramic Perovskite coating

Researchers and product developers are geared towards development of ceramic/perovskite coatings for metallic interconnects for high temperature operation at 1000°C. Improved alloy composition may be looked at as metallic interconnect. 

Good results are obtained with oxide-coated valve metals as anode materials. These electrically conducting ceramic coatings of p-conducting spinel-ferrite (e.g., cobalt, nickel and lithium ferrites) have very low consumption rates. Lithium ferrite has proved particularly effective because it possesses excellent adhesion on titanium and niobium [26]. In addition, doping the perovskite structure with monovalent lithium ions provides good electrical conductivity for anodic reactions. Anodes produced in this way are distributed under the trade name Lida [27]. The consumption rate in seawater is given as 10 g A ar and in fresh water is... 

Recent applications of e-beam and HF-plasma SNMS have been published in the following areas aerosol particles [3.77], X-ray mirrors [3.78, 3.79], ceramics and hard coatings [3.80-3.84], glasses [3.85], interface reactions [3.86], ion implantations [3.87], molecular beam epitaxy (MBE) layers [3.88], multilayer systems [3.89], ohmic contacts [3.90], organic additives [3.91], perovskite-type and superconducting layers [3.92], steel [3.93, 3.94], surface deposition [3.95], sub-surface diffusion [3.96], sensors [3.97-3.99], soil [3.100], and thermal barrier coatings [3.101]. 

In Chapter 10, the use of membranes for different applications are described. One of the possible membranes for hydrogen cleaning is an asymmetric membrane comprised of the dense end of a proton conduction perovskite such as BaCe0 95 Yb0 05O3 5 and a porous end to bring mechanical stability to the membrane. In this case, it is possible to take from the slurry, obtained by the acetate procedure, several drops to be released over a porous ceramic membrane, located in the spinning bar of a spin-coating machine. Thereafter, the assembly powder, thin film porous membrane is heated from room temperature up to 1573 K at a rate of 2K/min, kept at this temperature for 12 h, and then cooled at the same rate in order to get the perovskite end film over the porous membrane [50],... 

Numerous ceramics are deposited via chemical vapor deposition. Oxide, carbide, nitride, and boride films can all be produced from gas phase precursors. This section gives details on the production-scale reactions for materials that are widely produced. In addition, a survey of the latest research including novel precursors and chemical reactions is provided. The discussion begins with the mature technologies of silicon dioxide, aluminum oxide, and silicon nitride CVD. Then the focus turns to the deposition of thin films having characteristics that are attractive for future applications in microelectronics, micromachinery, and hard coatings for tools and parts. These materials include aluminum nitride, boron nitride, titanium nitride, titanium dioxide, silicon carbide, and mixed-metal oxides such as those of the perovskite structure and those used as high To superconductors. 

Composite membranes also employ dense cermets fabricated by sintering together mixed powders of metal and ceramic [10-12], Examples include powders of Pd and its alloys sintered with powders of perovskites [11,12], niobium sintered together with AI2O3 [12], and nickel sintered with proton-conducting perovskites. Layers of dense cermets, 25-100 xm thick, are supported by porous ceramic tubes. Cermets employing chemically reactive metals, Nb, Ta, U, V, Zr, and their alloys, are typically coated with Pd and alloys thereof [11,12],... 

I 8 Encapsulations Through the Sol-Cel Technique and their Applications in Functional Coatings 8.5.2.9 Perovskites and Ceramic Superconductors... 

Figure 110. Ceramic/cermet composite from a high-temperature fuel cell. The section has been subjected to contrast enhancement, BF. The composite was produced by slip casting and a coat mix process. P = perovskite Lao,84Sro,i6Mn03 YSZ = Y203-stabilized zirconium oxide.

Numerous studies have investigated coating the interconnect with a dense protective oxide layer to reduce surface oxidation and chromium contamination of other key components [124, 125]. Perovskite materials such as LaCrOs typically used for higher temperature ceramic interconnects are ideal as their conductivity and thermal expansion coefficient can be tailored through doping to ensure compatibility and optimise performance. 

Teraoka, Y., and Labhsetwar, N. (2013) Bench scale experiments of diesel soot oxidation using Pro,7Sro.2Ko.iMn03 perovskite type catalyst coated on ceramic foam filters. Top. Catal, 56 (18), 457-461. 

Li, L., Shen, X., Wang, P., Meng, X., and Song, E. (2011) Soot capture and combustion for perovskite La-Mn-O based catalysts coated on honeycomb ceramic in practical diesel exhaust. Appl. 

In the last decade, a variety of porous substrates were proposed for supporting the dense membranes, such as ceramics, metals, and alloys [42-44]. In those studies, special attention was paid to the LSCF coating on metallic substrates by using physical methods such as plasma spray physical vapor deposition and magnetron sputtering as an alternative to the wet chemical deposition methods [43,44]. When considering ceramic substrates, besides the elastic behavior and the thermal expansion of the perovskites, other properties such as toughness... 

The preparation of composite PCMs starts with the synthesis of porous substrates, followed by the formation of thin PCM films. Detailed procedures are illustrated in Figure 6.3. An exact procedure should be conducted to obtain thin, dense ceramic films [17].The carbon black content for the synthesis of porous substrates can be varied so as to determine conditions that match accurately the shrinkage profile of the porous substrates with that of the deposited perovskite films during the final sintering of the composite membrane. Partial sintering of the green substrates is conducted to match their subsequent shrinkage with that of coated powders so that fissures and cracks can be minimized. 

Stresses produced in sol-gel-derived films modify the lattice parameters of the film and its orientation or texture. These effects are clearly observed in the X-ray diffraction (XRD) patterns of Figure 27.16 [55]. The XRD pattern of a (Ca, Pb) TiOs perovskite thin film on a Pt-coated silicon substrate shows a textured film with a (100) preferred orientation and with the cell parameters for the perovskite indicated in Table 27.5. When this film is electrolytically separated from the substrate, it recovers the random orientation of the ceramic powder and its preferred orientation disappears observe the lattice parameters and strains measured in a (Ca, Pb)TiOs thin film on the substrate and this film is separated from the substrate in comparison with those of the bulk ceramic (Table 27.5) [55]. 

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