High-Temperature X-Ray Absorption and Diffraction Investigations of Pd and Pd–C Saturated Solid Solutions

A novel experimental set-up suitable for high-temperature X-ray measurements has been exploited to investigate pure Pd and the Pd–C system. The Pd–C eutectic temperature was measured using X-ray absorption temperature scans and found to be T_e = (1758 ± 8) K. An energy scanning X-ray diffraction set-up was used for accurate measurements of the lattice expansion of Pd and Pd–C saturated solid solutions in the 1250 to 1770 K temperature range. On the basis of these data we estimated the C solubility as a function of temperature and derived an improved phase diagram for the Pd–C alloy.