Outgassing of quartz

The outgassing of quartz crystal plates was measured with a high resolution mass spectrometer using thermal desorption techniques. As the quartz was heated from 40/spl deg/C to 1200/spl deg/C in a vacuum, the mass spectrometer identified several types of gases. The primary species that appeared were NH/sub 3/, OH, and H/sub 2/O. The bonding sites of the OH and H/sub 2/O are discussed, including the temperature dependence of the desorption peaks which is used to calculate the activation energies of the surface states. Bakeout times and temperatures to insure clean surfaces are calculated. The effect of bakeout conditions on aging is also discussed. The presence of NH/sub 3/ was unexpected, but it is believed that the NH/sub 3/ was due to the sample preparation which included etching the samples in ammonium bifluoride.<
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