Structure of Pt overlayers on ZnO(0001) and ZnO(000{bar 1}) surfaces
The growth of Pt films on the Zn- and O-terminated polar surfaces of ZnO has been studied. Clean surfaces, prepared by sputtering and annealing, were dosed with Pt by vapor deposition. Properties of the film were examined by low-energy alkali ion scattering and low-energy electron diffraction. It is confirmed that, near room temperature, Pt grows on both surfaces as a single hexagonal layer which aligns with the substrate low index directions. The alignment is better for the Zn-terminated than for the O-terminated surface. A Pt monolayer grows on the Zn-terminated surface until the ZnO surface is essentially covered with no evidence of a second Pt layer. Upon annealing above 675 K, pt agglomerates into mostly bilayer islands, but maintains or improves its alignment with the substrate. Features associated with scattering from bi- or multilayer Pt indicate that the Pt forms oriented (111) rafts. A coincidence LEED pattern indicates that the Pt lattice may be expanded by 0.5% to form a 6:7 coincidence overlayer with the ZnO lattice.
- Research Organization:
- Univ. of Tennessee, Knoxville, TN (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 20034428
- Journal Information:
- Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Vol. 104, Issue 14; Other Information: PBD: 13 Apr 2000; ISSN 1089-5647
- Country of Publication:
- United States
- Language:
- English
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