Rebonding at coherent interfaces between rocksalt-PbTe/zinc-blende-CdTe

We study interfaces between highly ionic crystals with different crystal structure by means of first-principles total-energy calculations in the repeated-slab approximation, and compare the results with experimental data extracted from high-resolution transmission electron micrographs. Despite the same Bravais lattices and the electrostatic neutrality of each atomic plane, the (110) interface between rocksalt and zinc-blende crystals gives rise to the most remarkable effect, a lateral spatial offset between the two crystals due to rebonding across the interface. A strong variation is observed for the separation of the two polar (001) interfaces depending on their cation- or anion-termination. In general, the long-range electrostatic forces lead to opposite atomic displacements along the interface normal independently of the interface orientation.