VO{sub 2} precipitates for self-protected optical surfaces
A method for forming crystallographically coherent precipitates of vanadium dioxide in the near-surface region of sapphire and the resulting product is disclosed. Ions of vanadium and oxygen are stoichiometrically implanted into a sapphire substrate (Al{sub 2}O{sub 3}), and subsequently annealed to form vanadium dioxide precipitates in the substrate. The embedded VO{sub 2} precipitates, which are three-dimensionally oriented with respect to the crystal axes of the Al{sub 2}O{sub 3} host lattice, undergo a first-order monoclinic-to-tetragonal (and also semiconducting-to-metallic) phase transition at ca. 77 C. This transformation is accompanied by a significant variation in the optical transmission of the implanted region and results in the formation of an optically active, thermally ``switchable`` surface region on Al{sub 2}O{sub 3}. 5 figs.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- Assignee:
- Dept. of Energy, Washington, DC (United States)
- Patent Number(s):
- US 5,885,665/A/
- Application Number:
- PAN: 8-853,947
- OSTI ID:
- 335489
- Resource Relation:
- Other Information: PBD: 23 Mar 1999
- Country of Publication:
- United States
- Language:
- English
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