Structural-and-phase states, crystallogeometric and crystallochemical parameters of membrane palladium-based alloys

The results of the analysis of the ordered phase equilibria in binary Cu-Ni, Cu-Pd, and Ni-Pd, and ternary Cu-Ni-Pd systems are presented. It has been established that the packing index in disordered solid solutions of binary systems Cu-Ni, Cu-Pd, and Ni-Pd is close to the value of 0.74, and is accompanied by an insignificant deviation from the Zen law of concentration dependences of atomic volumes. A significant decrease in the packing index has been observed in the ordered phase with a B2 structure in the range of 40 at.% Pd in alloys of the binary system Cu-Pd. The correlation between the jump in hydrogen-permeability and the change in the effective size of atoms-components has been revealed. This phenomenon manifests itself in a significant decrease in the packing index in the ordered phase with a B2 structure in the range of 40 at.% Pd.