1. |
- Lu, J. -L, et al.
(author)
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Formation of one-dimensional crystalline silica on a metal substrate
- 2006
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In: Surface Science. - : Elsevier BV. - 0039-6028 .- 1879-2758. ; 600:13, s. L164-L168
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Journal article (peer-reviewed)abstract
- We have observed formation of one-dimensional silica structures of 0.5 nm in width on Mo(112) single crystal surface. Combination of high-resolution scanning tunneling microscopy, photoelectron and infrared spectroscopy, and density functional theory provides strong evidence for formation of paired rows of corner sharing [SiO4] tetrahedra chemisorbed on a metal substrate.
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2. |
- Lu, J. -L, et al.
(author)
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Low temperature CO induced growth of Pd supported on a monolayer silica film
- 2006
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In: Surface Science. - : Elsevier BV. - 0039-6028 .- 1879-2758. ; 600:12, s. L153-L157
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Journal article (peer-reviewed)abstract
- Nucleation, growth and sintering of Pd deposited on an ultra-thin silica film were studied by scanning tunneling microscopy and infrared reflection absorption spectroscopy. No preferential nucleation of Pd on the silica surface was observed both at 90 and 300 K deposition. When adsorbed on Pd clusters formed at 90 K, CO causes a strong sintering effect even at this temperature. The results are rationalized on the basis of a high mobility of Pd carbonyl-like species on the silica film. At a given Pd coverage, the extent of CO induced sintering cannot be achieved by annealing in vacuum. In addition, vacuum sintering, which commences above 700 K, goes simultaneously with interdiffusion of Pd and support.
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3. |
- Lu, J. -L., et al.
(author)
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Structure, thermal stability, and CO adsorption properties of Pd nanoparticles supported on an ultra-thin SiO2 film
- 2007
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In: Surface review and letters. - 0218-625X. ; 14:5, s. 927-934
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Journal article (peer-reviewed)abstract
- Nucleation, growth, and thermal stability of Pd particles vapor-deposited on an ultra-thin crystalline silica film grown on Mo(112) have been studied by scanning tunneling microscopy, X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, and temperature-programmed desorption of CO. No preferential nucleation of Pd on the silica film is found at room temperature deposition: the hemispherical Pd nanoparticles are homogenously dispersed on the support at all coverages studied (0.01-1ML(mono layer)). The Pd particles are resistant toward sintering up to 700K as judged by STM; however, CO adsorption studies have revealed surface chemical modification at temperatures as low as 550K. Strong morphological changes are observed above 800K (ultimately resulting in elongated rectangular islands at similar to 1000 K), which is accompanied by strong alterations of CO adsorption properties. The results are rationalized in terms of Pd and Mo substrate interdiffusion at elevated temperatures, while the silica film basically preserves its structure.
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4. |
- Todorova, T. K., et al.
(author)
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Atomic structure of a thin silica film on a Mo(112) substrate : A combined experimental and theoretical study (vol 73, pg 165414, 2006)
- 2006
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:16
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Journal article (peer-reviewed)abstract
- The atomic structure of the thin SiO2 film on a Mo(112) substrate has been determined based on a combination of density functional theory calculations and high-quality experimental data obtained from scanning tunneling microscopy, infrared reflection absorption spectroscopy, and x-ray photoelectron spectroscopy. The film consists of a honeycomblike, two-dimensional network of corner-sharing [SiO4] tetrahedra. One oxygen atom of each tetrahedron binds to the Mo(112) substrate and is located in a bridge position between Mo atoms located in rows protruding from the metal surface. The other three oxygen atoms form Si-O-Si bonds with the neighboring tetrahedra.
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5. |
- Todorova, T K, et al.
(author)
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Atomic structure of a thin silica film on a Mo(112) substrate : A combined experimental and theoretical study
- 2006
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:16, s. 165414-
-
Journal article (peer-reviewed)abstract
- The atomic structure of the thin SiO2 film on a Mo(112) substrate has been determined based on a combination of density functional theory calculations and high-quality experimental data obtained from scanning tunneling microscopy, infrared reflection absorption spectroscopy, and x-ray photoelectron spectroscopy. The film consists of a honeycomblike, two-dimensional network of corner-sharing [SiO4] tetrahedra. One oxygen atom of each tetrahedron binds to the Mo(112) substrate and is located in a bridge position between Mo atoms located in rows protruding from the metal surface. The other three oxygen atoms form Si-O-Si bonds with the neighboring tetrahedra.
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6. |
- Weissenrieder, Jonas, et al.
(author)
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Atomic structure of a thin silica film on a Mo(112) substrate : A two-dimensional network of SiO4 tetrahedra
- 2005
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 95:7, s. 1-4
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Journal article (peer-reviewed)abstract
- The structure of a thin single crystalline SiO2 film grown on Mo(112) has been studied by scanning tunneling microscopy, infrared reflection absorption spectroscopy, and x-ray photoelectron spectroscopy. In excellent agreement with the experimental results, density functional theory calculations show that the film consists of a two-dimensional network of corner sharing [SiO4] tetrahedra, with one oxygen of each tetrahedron binding to the protruding Mo atoms of the Mo(112) surface.
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