Chemical SrZrO

Figure 8.35. A selection of " Zr NMR spectra. A. Stepped-frequency spin-echo spectra of 3 phases of Zr02, adapted from Bastow (1994). B. 14.1 T MAS NMR spectra of Ba and Sr zirconates. Asterisks denote spinning side bands. Note the broader lineshape with possible quadrupolar structure of the more distorted Zr site in SrZrO. From Dec et al. (1993), by permission of the American Chemical Society. C. Static stepped-frequency NMR spectrum of Na2ZrSi05. 1996. D. Stepped-frequency NMR spectrum of Zr metal (lower) with simulated spectrum (upper). 1992. D. Static Zr NMR spectrum of the central transition of A Zr. From Bastow et al. (1992, 1996, 1998b), by permission of the copyright owners.

Effective chemical diffusivities in the proton conductor, SrZro.95Ybo.05O3. were... 

This approach was applied also in [611] in the comparative study of chemical bonding in SrTiOa and SrZrOs crystals. The results of these calculations are discussed in the next section in the consideration of the projection technique for population analysis in crystals. 

As we saw in the example of SrZrOs crystal the absolute atomic-charge values differ in the different approaches to their calculation. Do different approaches (including those based on PW calculations) reproduce correctly at least the relative changes in the chemical bonding in crystals with analogous structure This point is discussed in the next section. 

The total DOS and PDOS give rich information on the chemical structure of a system, connecting the calculated band structure with the atomic states. We demonstrate this by considering total and projected DOS for binary oxides MgO, Ti02 and ternary oxides SrTiOa and SrZrOs with cubic perovskite structure (see Figures 9.5-9.S). 

Chemical compatibility (cathode) Manganite-based cathode materials have reasonable chemical compatibility with YSZ-based electrolytes. However, high sintering temperatures (>1200°C) can lead to the formation of electronically insulating SrZrOs and La2Zr207 phases.Introducing a slight (La, Sr) deficiency in the materials can decrease the unwanted reactivity to some extent. 

The formation of protons leads to the increase in conduction. The ord r o Pj conduction is given by CaZiOs < SrZrOs < BaCeOs whereas the chemical sta i ity followed the reverse trend for the SrZr03 as the most stable material. Figur shows the proton conduction for different materials. 

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