Hydrogen and oxygen motion in yttrium by anelastic relaxation

The role of interstitial hydrogen in the numerous relaxation processes observed in the pure yttrium has been studied by elastic energy loss measurements in the temperature range between 1.1 and 600 K, at vibration frequencies in the kHz range. All the processes below 300 K are caused by hydrogen: the process at liquid He temperature is due to its delocalization whereas three other processes originate from hopping of the H atoms trapped by oxygen (nitrogen) or dragged by dislocations. It is proposed that the effects above room temperature are associated with the motion of oxygen in solid solution.