The effect of the occlusion of hydrogen on the characteristic temperature of palladium and the vibration amplitudes of its atoms

Abstract

The method of arriving at the characteristic temperature by measuring the fall of intensity of reflection of x rays with increasing temperature by gas-free pure palladium leads to approximately the same value (267°K) as that deduced from specificheat and electrical-conductivity measurements, i.e. 270 and 275°K respectively. The characteristic temperature of palladium containing small amounts of hydrogen increases with increasing hydrogen concentration, reaching the value 311°K for a concentration of 0.7 at.% of hydrogen. The root-mean-square displacement of the palladium atoms at room temperature decreases with increasing hydrogen content from 0.131 A for gas-free palladium to 0.113 A for a concentration of 0.7 at.% of hydrogen.