Depth distribution of deuterium atoms and molecules in beryllium oxide implanted with deuterium ions

In-depth concentration profiles of deuterium (D) in beryllium oxide (BeO) films implanted with 3 keV D ions at 300 and 700 K have been determined using SIMS and RGA (residual gas analysis) measurements in the course of surface sputtering. The microstructure of implanted specimens was studied by TEM. Implanted D is found to be retained in the BeO matrix in the form of D atoms and D-2 molecules. At 300 and 700 K, the maximum concentration of deuterium in both states reaches values of 0.2 and 0.07 D/BeO, respectively. Irradiation with D ions at 300 and 700 K leads to the formation of tiny D-2 bubbles of 0.6-0.7 nm radius and of high volume density approximate to(4-5) x 10(24) m(-3). These bubbles together with the intercrystalline gaps are responsible for the accumulation of D-2 molecules. At both irradiation temperatures, D-2 concentration reaches in the ion stopping zone its maximum of 0.01 molecules/BeO. At 300 and 700 K, the major part of deuterium implanted in BeO films is present in the form of D atoms, probably chemically bound to O atoms. Maximum D atom concentration is 0.18 D atoms/BeO for 300 K and 0.05 D atoms/BeO for 700 K. (C) 1999 Elsevier Science B.V. All rights reserved.