Thermodynamic assessment of the Pd–H–D–T system

The three binary systems H–Pd, D–Pd and Pd–T have been modelled in the frame of the Calphad approach. A complete literature search has been undertaken and the most significant experimental data have been selected for a thermodynamic assessment of these systems. To complement the available data, pressure–composition curves have been measured for the three systems in the present work. The three systems are characterized by a strong isotope effect which is well taken into account in the modelling. They have been combined to perform calculations in the quaternary H–D–Pd–T system. It is shown that a reasonable extrapolation can be made without the use of ternary parameters if it is calculated with the so-called Toop model.