Thermodynamic and Kinetic Properties of Interstitial Solid Solutions.

Extensive measurements on the thermodynamic and kinetic properties of hydrogen in metals and metallic solid solutions both at high and low 300 K temperatures have shown that much of the previously existing data are in error due to the use of pure metal samples containing concentrations of interstitial or substitutional impurity elements higher than that of the species being studied. In general the behavior of H in defect solids can be understood in terms of simple models in which the distribution of the H-atoms between normal lattice sites and low-energy trapping sites is a Fermi-Dirac function. At high temperatures its Boltzmannian approximation is adequate.