Thermodynamic Behavior of Dilute Solutions of Hydrogen in Niobium

Abstract

In a recent paper on the thermodynamic properties of dilute solutions of hydrogen and deuterium in β‐titanium and β‐zirconium anomalous behavior was observed. It was concluded that a similar investigation on the niobium–hydrogen system might well provide a better insight into this phenomenon, should it prove to exist in the system, because the temperature range of dilute hydrogen solubility in the body‐centered cubic structure of the niobium–hydrogen system is much more extensive than in the corresponding titanium and zirconium systems. It has now been shown that departures from Sievert's law are present in dilute hydrogen solutions in niobium. Departures from random solution are well marked and prove to have a strong temperature dependence. An analysis of the thermodynamic behavior of the niobium–hydrogen system together with some results on the niobium–deuterium system would seem to indicate that a small degree of clustering is present in such dilute alloys.