EFFECT OF MICROSTRUCTURE UPON THE HYDROGEN DISTRIBUTION IN THIN PALLADIUM SHEETS UNDER STATIONARY PERMEATION CONDITIONS

The amount of hydrogen accommodated in a thin sheet of palladium under stationary flux conditions was measured by two different methods: (1) from the electrical charge spent for its removal, during the discharg ing cycle and (2) from the stationary permeation current. This amount was always higher in case (1) than in case (2) and was ascribed to the fraction of hydrogen segregated at the dislocations and to the differ ent effects it may have upon the transient flux in the charging- and d ischarging-cycle of the permeation measurements, respectively. Values of dislocation density have been calculated and compared with those es timated from X-ray diffraction measurements.