HAL Id: jpa-00214540
https://hal.archives-ouvertes.fr/jpa-00214540
Submitted on 1 Jan 1971
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THE DIFFUSION COEFFICIENT OF HYDROGEN IN NIOBIUM BETWEEN 120 AND 600 °K AS
DETERMINED BY GORSKY-EFFECT MEASUREMENTS
J. Völkl, G. Alefeld
To cite this version:
J. Völkl, G. Alefeld. THE DIFFUSION COEFFICIENT OF HYDROGEN IN NIOBIUM BE-
TWEEN 120 AND 600 °K AS DETERMINED BY GORSKY-EFFECT MEASUREMENTS. Journal
de Physique Colloques, 1971, 32 (C2), pp.C2-62-C2-62. �10.1051/jphyscol:1971214�. �jpa-00214540�
JOURNAL DE PHYSIQUE
Colloque C2, supplkment au no 7 , tome 32, Juillet 1971, page C2-62
MODULUS CHANGES DUE TO HYDROGEN IN VANADIUM
J. BUCHHOLZ, J. VOLKL and G. ALEFELD Kernforschung, Jiilich, Institut fiir Festktirperforschung
An internal friction apparatus (inverted torsion pendulum) which allows a digital data acquisition is described. The data are recorded on a tape and ana- lysed by computer.
With this apparatus internal friction and modulus measurements on a vanadium sample exposed
insitu to different hydrogen pressures at 400
OCwere perfor- med. The internal friction increases whereas the modulus decreases, both proportional to the square root of the hydrogen pressure thus indicating propor- tionality to the H-concentration in the sample. The
internal friction increase is caused by the Gorsky- effect of the solved hydrogen atoms. The absolute value is consistent with calculations using solubility datas whereas the modulus defect is about two orders of magnitude larger than it would be expected from the Gorsky-effect alone. The difference
is due to the dielastic and the Snoek-effect of the solved H-atoms.
THE DIFFUSION COEFFICIENT OF HYDROGEN IN NIOBIUM BETWEEN 120 AND 600 OK AS DETERMINED
BY GORSKY-EFEECT MEASUREMENTS
J. VOLKL and G. ALEFELD
Recent measurements of the diffusion coefficient From the temperature dependence of the relaxation of H in Nb were extended in temperature down to strength below 180 OK the amount of H still in solution 120 OK by using a sample with low H-concentration can be determined. Between 180 OK and 120 OK the (0.2 at % H) thus shifting precipitation to low tempe- solubility limit can be described by
ratures (180 OK). As in the region above room tem- perature'(~hys. Rev. Letters 1968 21, 891,) one finds
below 300 OK again an Arrhenius law but with smal-
c =(57 + ::)exp[(- 0,09 f 0,011 eV,kT] at % .
ler activation energy (0.068 eV) and smaller Do(9 x cm2/s).
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1971214
