Positron annihilation in solid and liquid Ni

Abstract

Analyses of the Doppler-broadening energy spectra for positrons annihilating in solid and liquid Ni are reported. Comparisons are made among the momentum distributions of positron-electron pairs annihilating in the essentially defect-free lattice, the vacancy and the liquid state of Ni. An interesting similarity in the distribution of momenta is reported for positrons annihilating in vacancies at high temperatures and those annihilating in liquid Ni.