RELEASE OF DEUTERIUM FROM CARBON-DEUTERIUM FILMS ON BERYLLIUM DURING CARBIDE FORMATION AND OXIDATION

Amorphous carbon-deuterium (a-C:D) films on beryllium substrates were vacuum annealed while the composition versus depth was followed using Rutherford backscattering, elastic recoil detection and Auger electron spectroscopy. The a-C:D film reacts with the Be substrate to form sto ichiometric beryllium carbide, Be2C. The reaction begins at the interf ace and progresses through the film around 500 degrees C until the ent ire film has reacted. D is absent from the reacted portion of the film but is still present in the unreacted carbon. The a-C:D films are rem oved from the Be without forming carbide by heating in oxygen at 400 d egrees C. Ion beam analysis was also used to study the oxidation of Be at temperatures up to 680 degrees C. Through sequential exposures to different isotopes of oxygen it was shown that oxidation occurs by per meation of Be from the metal/oxide interface to the outer surface. (C) 1997 Elsevier Science B.V.