Paper Title:
Atomic Motion and Diffusion Mechanism of Hydrogen in Amorphous Ceramics of the System Si-B-C-N
  Abstract

In this work we investigated the mobility of hydrogen in amorphous ceramics with the composition Si13B13C60N13 (AM26C). The material was derived from a pre-ceramic polymer and thermolyzed at 1000 °C. After thermolysis the AM26C ceramics are assumed to be separated in an amorphous SiC phase and an amorphous C(BN)x phase. To measure the diffusivities we used deuterium as a tracer, which was introduced via isotope exchange from the gas phase at temperatures between 700 °C and 1100 °C. Depth profiling was done with secondary ion mass spectrometry (SIMS). The profiles could be fitted with complementary error functions. The diffusivities obey an Arrhenius law. The activation enthalpy is 0.8 eV, the pre-exponential factor is 5×10-12 m2 s-1. These values are close to those found for glassy carbon and thin amorphous C-B-N films as reported in the literature. We therefore conclude that the amorphous C(BN)x phase is the transport path for hydrogen in AM26C ceramics. A direct interstitial diffusion mechanism can account for the activation enthalpy of 0.8 eV. The low value for the pre-exponential factor is attributed to an entropy factor arising from the temperature dependence of the chemical potential of hydrogen.

  Info
Periodical
Edited by
J. Čermák and I. Stloukal
Pages
63-68
DOI
10.4028/www.scientific.net/DDF.263.63
Citation
W. Gruber, G. Borchardt, H. Schmidt, "Atomic Motion and Diffusion Mechanism of Hydrogen in Amorphous Ceramics of the System Si-B-C-N", Defect and Diffusion Forum, Vol. 263, pp. 63-68, 2007
Online since
March 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: K. Konopka, M. Trzaska, Dariusz Oleszak, W. Zieliński, Krzysztof J. Kurzydłowski
249
Authors: Masataka Satoh, Tomoyuki Suzuki
Abstract:The impurity concentration dependence of the recrystallization rate of phosphorus implanted 4H-SiC(11-20) has been investigated by means of...
799
Authors: Mariusz Staszewski, M. Woch, Aleksandra Kolano-Burian, J. Barszcz, M. Buczek
Abstract:Structural transformations taking place during annealing of rapidly-quenched soft magnetic ribbons from the Finemet type and Hitperm type...
273
Authors: Sadahiro Tsurekawa, H. Fujii, V.A. Yardley, T. Matsuzaki, T. Watanabe
Abstract:Crystallization kinetics and texture evolution in iron-based amorphous alloys (Fe78Si9B13, Fe73.5Si13.5B9Nb3Cu1) under a magnetic field have...
1371
Authors: S. Ahmadi, H.R. Shahverdi, S.S. Saremi
Chapter 14: Nanomaterials and Nanomanufacturing
Abstract:Nano- crystallization of Fe55Cr18Mo7B16C4 bulk amorphous alloy has been analyzed by X-...
3858