Anomaly in the lattice expansion of PdHx above the critical point

Abstract

Abstract The change in length of a palladium sample is measured in the vicinity of the critical point as a function of hydrogen concentration by means of a miniature capacitance dilatometer mounted on a microbalance. The length changes near Tc exhibit an anomalous behaviour somewhat similar to that found by Zabel and Peisl in thermal expansion measurements on NbH0.31. The magnitude and hydrogen concentration dependence of this anomalous lattice expansion can be explained in terms of a model which takes spatial inhomogeneities in the host metal lattice into account.