Electron irradiation induced rock salt type structure from ZnO/Zn intergrowth

Electron irradiation of nano-size wurtzite (W)-type ZnO condensates with intimate mixture of parallel epitaxial Zn caused { 1   0   1 ¯   1 } W slip to form a single domain of rock salt (R)-type core and W-type shell. The two polymorphs follow ( 1   1 ¯   1 ) R / / ( 0   1 ¯   1   1 ) W ; [ 0   1   1 ] R / / [ 1 ¯   2   1 ¯   3 ] W , i.e. chair type Peierls distortion with additional 38° tilting (0 0 1)R along the ( 1 ¯   2   1 ¯   0 ) W plane for a fair match of ( 1   0   1 ¯   1 ) W / ( 1   1 ¯   1 ) R , the same as one of the two paths for the back-transformation of R-ZnO into a lower crystal symmetry. The martensitic nucleation of R-type ZnO can be attributed to dynamic migration of interstitials/vacancies, lattice mismatch stress, and capillarity effect.