Differential scanning calorimetry and Mossbauer spectroscopy of hydrogenated Pd-C, Ni-C and Fe-Ni-C alloys

Palladium hydride formed in the Pd-C alloy is less stable than in carbon-free palladium, while the hydrides in FCC Fe-Ni-C and Ni-C alloys are more stable than in carbon-free metals. To investigate the effect of carbon on the stability of hydrides, the outgasing process of the hydrogenated alloys is studied by differential scanning calorimetry and Mossbauer spectroscopy. The former measurement gives the values of the heat of reaction and the latter clarifies the carbon-metal, hydrogen-metal and carbon-hydrogen interactions in the alloys. The observed effect of carbon on hydride formation is interpreted by combining lattice distortion theory and electron theory.