The effect of interstitial H concentrations and structural defects on the spectra of the lifetimes of positrons was investigated. The defects were produced by quenching at various temperatures up to that of liquid N, or by stretching. It was found that the spectra of the positron lifetimes were best described by a 2-component distribution. On the basis of the 2-state model of annihilation, it was concluded that the initial temperature from which quenching began, or the relative elongation which was caused by external forces, markedly affected the concentrations and sizes of defects in the sample.

Investigations into the Influence of Hydrogen and Defects on the Spectra of Lifetimes of Positrons in Palladium. R.Pietrazak, R.Szatanik, W.Smiater: Acta Physica Polonica A, 2001, 99[3-4], 455-63