Supersaturation and hydride formation in the dilute phase of Pd-H

Annealed Pd exhibits supersaturation of the dilute phase before the hydride phase forms and this is characterized here by measurements of both ∣ΔHH∣ and pH2. Pd, which has a high dislocation density, however, does not exhibit supersaturation, and its ∣ΔHH∣ values are a continuous function of H/Pd, in contrast to annealed Pd where there is a discontinuity at the phase boundary.