Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 39: Topical Session Theory meets Experiment IV - Batteries, Thermoelectrics and Thermal Barrier Coatings
MM 39.5: Vortrag
Mittwoch, 28. März 2012, 17:30–17:45, TC 006
Phase Stability in Yttria-stabilized Zirconia from First Principles — •Christian Carbogno1,2, Carlos G. Levi1, Matthias Scheffler1,2, and Chris G. Van de Walle1 — 1Materials Department, University of California, Santa Barbara, CA 93106-5050, USA — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4–6, 14195 Berlin, Germany
Zirconia based ceramics are of pivotal importance for a variety of industrial technologies, e.g., for
thermal barrier coatings in gas and airplane turbines [1]. Naturally, the stability of such coatings
at elevated temperatures plays a critical role in these applications. It is well known that an aliovalent
doping of tetragonal ZrO2 with Yttria, which induces oxygen vacancies due to charge conservation,
increases its thermodynamic stability [1,2]. However, the atomistic mechanisms that determine the phase stability
of such Yttria-stabilized Zirconia (YSZ) coatings are not yet fully
understood [2]. In this work, we use density functional theory calculations to assess the electronic structure
of the different YSZ polymorphs at various levels of doping. With the help of population analysis schemes, we are
able to unravel the intrinsic mechanisms that govern the interaction in YSZ and that can so explain the relative
stabilities of the various polymorphs. We critically compare our results to experimental measurements and discuss
the implications of our findings with respect to other oxides.
[1] A. G. Evans, D. R. Clarke, and C.G. Levi, J. Eur. Ceram. Soc. 28, 1405 (2008).
[2] J. A. Krogstadt et al., J. Am. Ceram. Soc. 94, S168 (2011).