International Meeting on Hydrogen in Metals at Kernforschungsanlage Jülich, Germany
International Meeting on Hydrogen in Metals at Kernforschungsanlage Jülich, Germany
The hydrogen pressure at the surface of a metal sheet immersed in an electrolyte can be measured by means of the electrochemical potential, if the hydrogen ionic activity is known (Nernst's equation). With proper activation of the metal surface the equilibriumdistribution between hydrogen disso...
Saved in:
Personal Name(s): | Alefeld, G. (Editor) |
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Brodowsky, H. (Editor) / Völkl, J. (Editor) / Wicke, E. (Editor) | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich GmbH Zentralbibliothek, Verlag
1972
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Physical Description: |
XI S., S. 38-846, Anh. |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte der Kernforschungsanlage Jülich
6,2 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The hydrogen pressure at the surface of a metal sheet immersed in an electrolyte can be measured by means of the electrochemical potential, if the hydrogen ionic activity is known (Nernst's equation). With proper activation of the metal surface the equilibriumdistribution between hydrogen dissolved in the metal and in the electrolyte prevails at all times. By means of the p-n-equilibrium isotherms this yields the relationship between the atomic ratio H/Pd within the metal and the electrochemical potential, that is, achange in hydrogen content in the metal produces a change in the electrochemical potential. On this basis various techniques have been developed for the measurement of diffusion coefficients. - These methods are described in a short review.- For measuring diffusion of hydrogen, particularly in Pd and Pd-Ag alloys, electrochemical time-lag methods - the jump and the pulse technique -, have proven especially suitable. With simple equipment diffusion coefficients from 10$^{-6}$ to 10$^{-10}$ cm$^{2}$ s$^{-1}$ are obtained conveniently (H in Pd and Pd-Ag 40-60 respectively). With the jump method the dependence of the diffusion coefficients of H in Pd and Pd-Ag alloys on hydrogen concentration could be established up to a silver content of about 60 atomic percent(P$_{H_2} \lesssim$ 1 atm), while by means of the pulse method the dependence of diffusion coefficients of H and D in Pd and Pd-Ag alloys on the silver concentration are obtained with vanishing hydrogen-isotope content.390 |