Self-Assembling of Nanocavities in TiO₂ Dispersed with Au Nanoclusters

Journal Article · Thu Dec 01 04:00:00 EST 2005 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.72.245421· OSTI ID:989525

Wang, C M ^[1]; Zhang, Y ^[1]; Shutthanandan, V ^[1]; Baer, D R ^[1]; Weber, William J ^[1]; Thomas, L E ^[1]; Thevuthasan, S ^[1]; Duscher, Gerd J M ^[2]

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1. Pacific Northwest National Laboratory (PNNL)
2. ORNL

There has been considerable research effort on tailoring the nonlinear optical properties of dielectric materials by dispersing nanometer-sized metallic clusters in them. It has been proposed that the optical response of this type of material is related to the quantum antidots (vacancy clusters), which is spatially located at the interface between the metal cluster and the dielectric matrix. In order to clarify the vacancy clustering behavior as well as its correlation with Au clustering, single crystal TiO{sub 2} has been implanted with Au ions at 975 K and subsequently annealed at 1275 K for 10 h. A characteristic self-assembling of nanocavities along the boundary between the region of Au clusters and the free surface has been observed in the present system. These cavities are faceted along TiO{sub 2}(110) and have a size of {approx}10 nm. High angle annular dark-field (HAADF) imaging in an aberration corrected scanning transmission electron microscope (STEM) revealed that vacancy clusters of {approx}2 nm in size also exist in the Au populated regions. Formation of cavities in Au-irradiated TiO{sub 2} strongly indicates that vacancy clustering processes prevail over Frenkel-pair recombination. Furthermore, the Au atoms substitution for Ti in TiO{sub 2} is also directly observed by STEM-HAADF imaging and by channeling Rutherford backscattering spectrometry.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 989525
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 24 Vol. 72; ISSN 1098-0121; ISSN 1550-235X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMS
CAVITIES
CHANNELING
DIELECTRIC MATERIALS
ELECTRON MICROSCOPES
MONOCRYSTALS
OPTICAL PROPERTIES
RECOMBINATION
RUTHERFORD BACKSCATTERING SPECTROSCOPY