Observation of new phases in Pd–D systems

Abstract Deuterium thermal desorption spectra (TDS) were taken from Pd samples which were pre-implanted with different doses of 25 keV D 2 + ions at T irr ∼100 K. The TDS were used to investigate the variations in deuterium concentration in Pd samples during their heating. The plotted annealing curves show a step-like structure typical of phase transitions. The phase composition variations were traced as the deuterium concentration in Pd increased from D/Pd=0 to D/Pd≈1. It was found that the β -phase (Pd β -hydride) was growing up to deuterium concentration D/Pd=0.5. At 0.5 γ -phase) was observed, which had thermodynamic characteristics much different from those of β -phase. The γ -phase formation causes the β -phase to modify into the β ′-phase that has a lower decomposition temperature.