Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 51: Oxides and insulators: Epitaxy and growth
O 51.10: Vortrag
Mittwoch, 28. März 2012, 19:00–19:15, HE 101
Density Functional Theory study of ZrO2 bulk phases and Pt3Zr-ZrO2 interfaces — •Wernfried Mayr-Schmölzer, Florian Mittendorfer, and Josef Redinger — IAP and Center of Computational Materials Science, TU Vienna
Zirconium dioxide is a material with many interesting properties, which make it useful for example as a solid electrolyte in solid-oxide fuel-cells or as an oxygen gas sensor.
We present results of DFT calculations with the Vienna Ab-initio Simulation Package of four ZrO2 bulk modifications and Pt3Zr-ZrO2 interfaces using different functionals, namely LDA, PBE, PBEsol and hybrid functionals (HSE). The ZrO2 phases we studied were the monoclinic P21/c, the tetragonal P42/nmc, the cubic Fm3m and the orthorhombic Pnma phase. For each functional a structural relaxation of the bulk crystal was done and compared to both earlier calculations and experiments.
To determine the correct interface between a Pt3Zr substrate and a thin film of zirconium oxide we first had to identify the stacking order of the Pt3Zr surface termination. A Pt3Zr crystal forms a hexagonal lattice with an ABAC stacking order. It is known from experiments that steps on the surface are two layers high, but using STM it is not possible to measure whether there is an A-A or a B-C step. Using DFT calculations we were able to identify the termination layer of the crystal. These results were then used to study the interface between a Pt3Zr substrate and a thin film of zirconium oxide.