Study of nanophase TiO/sub 2/ grain boundaries by Raman spectroscopy

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6000098

Melendres, C A; Narayanasamy, A; Maroni, V A; Siegel, R W

Raman spectra have been recorded for as-consolidated nanophase TiO/sub 2/ samples with differing grain sizes and on samples annealed in air at a variety of temperatures up to 1273 K. The nanophase samples with the smallest grain size, about 12 nm average diameter, could have 15-30% of their atoms in grain boundaries; nevertheless, the strong Raman-active lines representative of the rutile structure were found to dominate all of the observed spectra, independent of grain size and annealing treatment. These lines were quite broad in the as-consolidated nanophase samples, equally in 12 nm and 100 nm grain-size compacts, but sharpened considerably upon annealing at elevated temperatures. The Raman data give no indication of grain-boundary structures in nanophase TiO/sub 2/ that are significantly different from those in conventional polycrystals. However, defect structures within the grains, which anneal out at elevated temperatures, are evidenced by changes in the Raman spectra. 15 refs., 2 figs.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6000098
• Report Number(s): CONF-890426-12; ON: DE89012416
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
ANNEALING
CHALCOGENIDES
CRYSTAL STRUCTURE
CRYSTALS
GRAIN BOUNDARIES
GRAIN SIZE
HEAT TREATMENTS
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
POLYCRYSTALS
RAMAN SPECTRA
SIZE
SPECTRA
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS