Thermal Desorption Spectra of PdHx System (0<x<0.9) in Different Samples: A Powder, a Foil and a Wire
A preliminary report on the thermal desorption spectra of hydrogen in the PdHx system is presented for various initial hydrogen concentrations (0<xo<0.9) and for various samples: a powder, a thin foil and a wire. The results show a two-peak structure for the powder and the foil, and a structure that consists of two peaks and a shoulder for the wire. It is shown that in the powder and the foil the desorption rate is surface limited and the bulk protons are in equilibrium, whereas for the wire, bulk diffusion limits the desorption rate. Therefore, while a correlation between the spectra of the powder and the foil to the Pd-H phase diagram can be made, such a correlation for the wire is not readily attainable.
KeywordsOnset Temperature Desorption Rate Bulk Diffusion Thermal Desorption Spectroscopy Short Diffusion Distance
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- 3.J. Crank, “The Mathematics of Diffusion”, Clarendon Press, Oxford (1975)Google Scholar
- 4.W. Jost, “Diffusion in Solids, Liquids, Gases”, Academic Press Inc., Publishers, New York (1952).Google Scholar
- 5.J. Völkl and G. Alefeld, Diffusion of Hydrogen in Metals, in “Topics in Applied Physics”, Vol. 28, “Hydrogen in Metals I”, G. Alefeld and J. Völkl ed., Springer-Verlag, Berlin Heidelberg, New York (1978).Google Scholar
- 7.E. Wicke and H. Brodowsky, Hydrogen in Palladium and Palladium Alloys, in “Topics in Applied Physics”, Vol. 29, “Hydrogen in Metals II”, G. Alefeld and J. Volkl ed., Springer-Verlag, Berlin Heidelberg, New York (1978).Google Scholar