Ryszard Pietrzak

The electromigration and diffusion of hydrogen in molybdenum

Abstract The electromigration and diffusion of hydrogen atoms in molybdenum were investigated using the resistance method in the temperature range 293–773 K. The following dependence of the diffusion coefficient D and electrical mobility vE on temperature were obtained: D = (5.3 ± 1.53) × 10 −10 exp {− (0.8 ± 0.01) eV kT } { m 2 s −1 } v E = (1.24 ± 0.19) × 10 −8 exp {− (0.9 ± 0.01) eV kT }{ m 2 ( V s ) −1 } . The hydrogen migrates towards the cathode and the effective valency grows with temperature, fulfilling the relation Z eff = (1.42 ± 0.03) − (5.0 ± 0.2) × 10 −8 (Ω m ) ρ ; where ρ is the specific electric resistance.

Effect of the hydrogen concentration on the migration of tritium in a Hall electric field in Ta-H alloys

Abstract The effect of the hydrogen concentration in the TaH x system (0 ⩽ × ⩽ 0.13) on the kinetics of migration of tritium in a Hall electric field was investigated. It was found that the tritium migrates towards the positive Hall electrode. The effective valency of tritium is of the order of 10 3 and the ratio of the effective valency to the thermodynamic factor decreases with increasing concentration of hydrogen. The transverse electric mobility of tritium changes insignificantly with increasing concentration of hydrogen.

Investigation of diffusion and migration of hydrogen, deuterium and tritium in palladium in a Hall field

Abstract The migration of hydrogen, deuterium and tritium in palladium in a Hall field at 343 K was investigated, using resistance and isotope methods. It was found that all isotopes of hydrogen migrate towards the negative Hall electrode. The effective charges of the migration in a Hall field are 194 ±3 e for hydrogen and 464± 5 e for deuterium and tritium. The results obtained confirm predictions of a tentative model based on the electron-balistic theories of migration in a Hall field.

Electromigration and diffusion of hydrogen in amorphous alloys of Pd82Si18-type

The aim of this work was to determine the direction of electromigration and the values of the effective valency of hydrogen in amorphous alloys Pd 82 Si 18 H y for different hydrogen concentrations and for two alloys Pd 82-x Ni x Si 18 H y

Investigation of the electromigration of tritium in tantalum

Abstract The diffusion and electromigration of tritium in TaHT systems in α and ϵ phases has been investigated. The diffusion coefficient and the ratio of the effective valency to the thermodynamic factor ƒ were determined from radioactivity measurements of tritium. It has been found that during the phase transformation α → ge the effective valency changes in sign from positive to negative.

Effect of the temperature on tritium migration in a hall field in the Ta-H and Zr-H systems

Abstract The migration of tritium in a Hall field in TaH 0.015 and ZrH 0.015 systems has been investigated in the temperature range 291–576 K. It was found that the tritium migrates towards the positive Hall electrode. The effective valency migration of tritium in a Hall field is of the order of 10 4 -10 6 . The ratio of the effective valency to the thermodynamic factor decreases with increasing temperature for ZrH 0.015 and increases for TaH 0.015 .

Effect of hydrogen on the positron annihilation and Hall effect in metallic glasses

In the present study positron annihilation (in combination with the Hall effect and density measurements) is used to investigate the effect of electrolytic hydrogenation on the parameters of the electron structure of the Ni 73 TM 5 Si 10 B 12 metallic glasses (where TM denotes nickel or chromium)