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Article history:Received 28 November 2008Received in revised form 5 March 2009Accepted 28 April 2009Available online 3 May 2009PACS:68.55.Ln82.80.Yc81.07.BcKeywords:CVD diamond filmsHydrogenGrain size dependenceERDAXPSRS In this investigation, diamond thin films with grain size ranging from 50 nm to 1 µm deposited using hotfilament chemical vapor deposition (HFCVD) have been analyzed by elastic recoil detection analysis (ERDA)for determining hydrogen concentration. Hydrogen concentration in diamond thin films increases withdecreasing grain size. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) results showed thatpart of this hydrogen is bonded to carbon forming C–H bonding. Raman spectra also indicated the increase ofnon diamond phase with the decrease in crystallite size. Incorporation of hydrogen in the samples andincrease of hydrogencontent in nanocrystalline sample are discussed. Large separation between filament andsubstrate used for the synthesis of nanocrystalline film helped to understand the large incorporation ofhydrogen in nanocrystalline diamond films during growth. The study addresses the hydrogen trapping indifferent samples and higher hydrogen concentration in nanocrystallites by considering the synthesisconditions, growth mechanisms for different grain sized diamond films and from the quality of CVD diamondfilms.© 2009 Elsevier B.V. All rights reserved.

Range distributions of fluorine for 19F+ implantation into SnO2, indium–tin oxide, AgGaS2 and AgGaSe2 are measured by using the 19F(p,αγ)16O resonant nuclear reactions. The electronic stopping cross sections for 19F ions in these materials are derived from the measured range distributions. These experimental results are compared with those obtained from the newest version of stopping and range computer code, SRIM2003. The values of projected range predicted by the SRIM2003 agree well with the measured values for AgGaS2 and AgGaSe2 substrates. However, the values given by the SRIM2003 substantially deviate from the experimental values for the oxide materials SnO2 and ITO.

Pb+ ions have been implanted into LiNbO3 crystals in the energy range of 100-350 keV at doses of 5×1015, 1×1016 and 2×1016 ions/cm2. The profile of the implanted ions was measured by Rutherford backscattering. The mean projected range and the range straggling obtained from the experiment were compared with the TRIM'98 and SRIM 2000 code. In the present case, the TRIM'98 code predicts experimental values better than those of the SRIM 2000 code. The depth distribution is also found to be independent of dose for 350 keV Pb+ implanted into LiNbO3 crystals. After 800°C annealing for 60 min in ambient air, obvious diffusion occurs to the implanted Pb+ ions at 150 keV with a dose of 5×1015 ions/cm2. After a low-temperature treatment at 77 K in liquid nitrogen, no obvious diffusion phenomenon occurs for the implanted Pb+ ions in LiNbO3.

Monte Carlo simulation is used to study the low energy He ion challenging in a (17,0) single-wall nanotube and its rope. The simulation shows that the channelling critical angle Psi(C) = 48E(-1/2) (E is incident energy) for a 1.31-nm-diameter initial beam into the nanotube, while Psi(C) = 45E(-1/2) for the 1.31-nm-diameter initial beam into its rope.