By means of a simple analysis, it was shown that twinning in -Zr polycrystals was markedly affected by the presence of low concentrations of impurity atoms. It was concluded that the motion of impurity atoms was an important factor which had to be taken into account when attempting to establish criteria for twinning.

M.P.Biget, O.Saada: Journal de Physique III, 1995, 5[11], 1833-40