Flame-made titanates

In contrast to conventional micron-sized particles, the nanoscale flame-made particles do ensure a more homogeneous distribution of elements and consist of single crystallites with the desired stoichiometry. As a consequence of the more homogenous elemental distribution in flame-made titanate particles, a better performance in terms of conductivity is observed. 

Similarly to flame-made titanates, the precise control of the stoichiometry and material purity has an influence on the electronic properties of perovskite-type oxides such as LSC, LSCF, and BSCF. While conductivity is comparable with the highest reported in the literature (Figure 4.5), other unique properties are documented for these flame-made compositions. LSC, LSCF, and BSCF from a FSS process feature a pronounced shift of the temperature, at which the maximum conductivity is observed. The FSS process resulted in materials with an exceptional electronic conductivity, which may better match to a SOFC operated at intermediate or low temperatures. For example, LSCF cathodes based on flame-made nanopowders have shown polarization resistances in the range of 0.7 Q. cm at 592 °C [59], which are among the lowest reported for thick film layers of this material stoichiometry. Similar conclusions were drawn with respect to LSC-based cathodes, for which very low overpotentials were documented [60]. 

Introduction The enchanting flame has held a special mystery and charm the world over for thousands of years. According to Greek myth, Prometheus the Titan stole fire from the heavens and gave it to mortals—an act for which he was swiftly punished. Early people made use of it anyway. Soon the ancients came to regard fire as one of the basic elements of the world. It has since become the famihar sign of the hearth and the mark of youth and blood—as well as the object of intense curiosity and scientific investigation. 

Fig. 8.1 Using DuPont Thermo-Man to test Bristol Uniforms (UK) turnout gear made from Hainsworth TITAN fabric that incorporates DuPont Nomex and DuPont Kevlar fibres (note that the test is to EN 469 using a flame source of 84kWm" for 8 s) (a) before,...

Synthetic ruby 2 %Ct20 in a-Al203) for lasers is made industrially by the Verneuil method as are single crystals of corund itself, sapphire, rutile, spinels, and strontium titanate. In this method the oxide particles are dropped through a flame,... 

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