Thermodynamics of hydrogen solution in Pd-Y alloys

Thermodynamic factors, (∂lnpH21/2/∂lnr)T where r = H-to-metal, mol ratio, are needed for the interpretation of diffusion parameters. From equilibrium isotherms, lnpH21/2vs lnr, the slopes give the thermodynamic factors over a range of H contents and temperatures. Plots of the thermodynamic factors as a function of r exhibit minima which suggests that Fick's diffusion constants should also exhibit minima.