The effect of radiation upon Li-vacancy ordering in -LiAl (Fd3m) was studied by means of Li-ion bombardment. It was found that the Li-vacancy ordering in -Li0.50Al0.50 was destroyed by the bombardment; thus indicating a relatively weak interaction between the Li vacancies. On the other hand, the Li-vacancy ordering in -Li0.48Al0.52 was not destroyed by bombardment. This suggested that there was a relatively strong interaction between the Li vacancies. It was proposed that this was responsible for the body-centered tetragonal arrangement of Li vacancies which was observed in neutron-diffraction studies. An increase in residual resistivity after bombardment suggested the existence of 2 Frenkel-type defects: a Li interstitial plus a Li-vacancy pair, and an Al interstitial plus an Al-vacancy pair. The latter defect was responsible for an annealing stage above the Li-vacancy ordering temperature. These defects disappeared completely during annealing at room temperature.

K.Kuriyama, T.Kato, H.Sugai, H.Maeta, M.Yahagi: Physical Review B, 1995, 52[5], 3020-2