The local structural properties of Hg1 - x Cdx Te, Hg1 - x Znx Te, and Cd1 - x Znx Te are examined using a self-consistent pseudopotential approach. An accurate description of the limiting crystals is obtained by adding empirical corrections to ab initio total energies calculated with the group-II d states included in the cores. Similar calculations for x = 0.5 ordered alloys confirm the presence of nearest-neighbor bond-length differences in these systems without violation of Vegard's law. An anomalously large “relaxation” is predicted here for Hg1 - xCdx Te(~2% bond-length difference in the alloy compared to only 0.3% between limiting crystals) due to the dominance of chemical effects neglected from simple valence force models. The implications of the present results for alloy mixing energies and possible deviations from randomness are discussed.
|Number of pages
|Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
|Published - Sep 1987
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films