[CITATION][C] A conjecture on a possible relation between the 55K heat capacity anomaly in palladium hydride and the modification of the vibrational spectrum of …

G Boureau, OJ Kleppa - Scripta Metallurgica, 1977 - Elsevier
Since the discovery by Nace and Aston (1, 2) of a heat capacity anomaly at 55K in the
palladium-hydrogen system, numerous attempts (3-10) have been made to explain it, but up
to now, no satisfactory explanation has been given. It is often assumed that this
transformation, which is associated with an entropy change of about 0.5 R per mole H,
represents an ordering transformation mainly involving the hydrogen atoms. However, as
recently pointed out by Jacob; and Vaughan (9), heat capacities calculated from the …