Mechanism of ion movement in AgCl and AgBr

The following mechanisms for ion movement in AgCl and AgBr have been studied: direct vacancy migration, direct interstitial migration and collinear as well as noncollinear jumps of interstitial ions. For the last two processes, we have carried out a path-variation study. The activation energies are high (⩾1.0 eV) for all the migration mechanisms considered here except for the collinear jump which has an activation energy around 0.6 eV. For both the collinear and noncollinear jumps, the paths of migration have been worked out.