Why are there solid lines drawn connecting the solid circles after twinning has taken place? Ideally, that explains a real plane, isn't it? But why are we going to get a plane out of nothing if we mechanically twin or a twinning is followed after heat treatment(annealing twins)?


1 Answer 1


solid circles represent the positions of atoms in the twinned region; these black circles represents the only atoms that are present there, whereas dashed circles are their original positions that after twinning are no more occupied on account of displacement.

These black atoms are displaced from their original positions on account of twinning and hence form novel planes that are not found in the untwinned regions.

  • 1
    $\begingroup$ What do you mean by "novel planes" $\endgroup$
    – user586228
    Commented Jan 12, 2021 at 10:04
  • $\begingroup$ the "novel planes" are those found only in the twinned region. If you look at the figure, you can see black lines connecting the displaced black atoms; these black lines are not found outside the twinned region and represent what I call 'novel planes'. I call them 'novel' because are not found in the original untwinned crystal, but form as a consequence of twinning, that is in a successive time. $\endgroup$
    – gryphys
    Commented Jan 12, 2021 at 10:36
  • $\begingroup$ Great answer..:)Btw can you tell me something why is the twinning region stopping s=at some point and the original configuration continuing after that? Please explain me this. Why this mirror like thing? $\endgroup$
    – user586228
    Commented Jan 12, 2021 at 11:22

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .