Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!decwrl!stanford.edu!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: merkle@parc.xerox.com (Ralph Merkle) Newsgroups: sci.nanotech Subject: Re: Diamonds? Message-ID: Date: 9 Apr 91 02:37:35 GMT Sender: nanotech@athos.rutgers.edu Lines: 30 Approved: nanotech@aramis.rutgers.edu Diamond was recently named "molecule of the year" by Science (volume 250, December 21 1990). On page 1641 it says: "Vapor deposition methodology now appears to be in an exponential phase of growth. Diamond films can be grown at pressures ranging from tens of torrs to 1 atmosphere. Film growth rates of 1 millimeter per hour are possible. Diverse volatilization methods have become available, including microwave discharges, hot filaments, plasma torches, and ion beams. The deposition of films at lower-than-normal temperatures (around 300 degrees C instead of the standard 700 to 1100 degrees C) has been accomplished through the addition of halogens to reaction mixtures; this is an important step if diamond is to be deposited on temperature- sensitive substrates. All of these variations on the basic CVD [chemical vapor deposition] theme are making possible faster production of better materials with diverse morphologies." In another section, the article states that "...one estimate is that diamond chips might be able to withstand temperatures as high as 5000 degrees C." Clearly, diamond can be synthesized at room temperature and at low pressure. The argument that diamond is "thermodynamically unstable" is irrelevant if the time required for it to adopt a "stable" form exceeds the life of the universe. Many things are "thermodynamically unstable" but last quite a long time and are quite useful. "Diamonds are forever" is perhaps an exaggeration, but does indicate that the useful lifetime of diamond structures, provided that you refrain from putting them in a furnace, should be quite long.