Using Monte Cario simulation have been carried out an.atomistic description of the structure and ordering processes in the system Cu - Au in a two-dimensional model. The ABV model of the alloy is a system of N atoms A and B, located in rigid lattice with sorne vacañt sites. In the model we assume pair wise interactions between nearest neighbors with constant ordering energy J,;, 0.03 eV. The dynarnics was introduced by means of a vacancy that exchanges of place with any atom of its neighbors . The simulations were carried out in a square lattice with 1024 and 4096 particles, using periodic boundary conditions to avoid border effects. We calculate the first two parameters of short range arder of Warren-Cowley as function of the concentration and tenl.petature. It was also studied the probabilities of formation of different atomic clusters that consist of 9 atoms as function of the concen...

A new superlattice in semiconductors is discussed which allows to determine the geometrical stability and precision of delta-doping layers in respect to migration and diffusion effects, and even a technological evaluation of the production devíce. This structure acts as inner probe in doping superlattices quite as the known case of enlarged wells in composition superlattices does. Donor - acceptor - pair luminescence radiation is used, which in its dependence on the pair separation distance reflects the geometrical arrangement of neighboring delta­ doped layers provided both donors and acceptors are present in each sheet.