Chaoite is an allotrope of carbon discovered in 1968 in shock-fused graphite gneiss from the Ries crater in Bavaria. Its reflection colour is grey to white, and it is slightly harder than graphite. [1] Allotropy (Gr. ... The Nördlinger Ries is a depression in western Bavaria, Germany, located north of the Danube in the district of Donau-Ries. ...
Ceraphite
It has been claimed that an identical form can be prepared from graphite by sublimation at 2700-3000 K or by irradiating it with a laser in high vacuum. This substance has been termed ceraphite. [2]
A review [3] cautions that "in spite of these seemingly definitive reports … several other groups have tried unsuccessfully to reproduce these experiments. Independent confirmatory work is obviously needed … and at the present time white graphite appears to be the carbon analog of polywater." Polywater was a hypothetical polymerized form of water that was the subject of much scientific controversy during the late 1960s. ...
Sources
^ A. El Goresy, G. Donnay, Science 1968, 161, 363.
^ C. Nakayama, M. Okawa, H. Nagashima, Carbon 1977, 15, 434; D.J. Johnson, D. Crawford, C. Oates, 1971, 10th Carbon Conf, Bethlehem, PA, FC-18.
The substrate to be coated with a chaoite coating is positioned on a support table (unnumbered) so that the substrate surface facing the heated band of the graphite rod is removed therefrom approximately a few centimeters.
The substrate to be coated with a film of chaoite is positioned to have the carbon vapor impinge on its surface within the temperature range of 2600.degree.-2800.degree.
Having described the present invention with respect to the formation of a chaoite film, it will become apparent to those skilled in the art that the invention may be practiced with modifications thereto without departing from the spirit of this invention.
Products termed "metastable carbon phases" typically include diamond, lonsdaleite (or hexagonal diamond), chaoite and carbon VI (sometimes called white carbon),.alpha.-carbyne and.beta.-carbyne.
Chaoite was produced during graphite sublimation at 2400.degree.-2700.degree.
Attempts to dissolve the particulates with oxidizing acids, which are useful for graphite, were generally unsuccessful thus further indicating them to be nongraphite.
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