The structural and thermodynamical properties of GaxIn1-xP solid solutions are studied using Monte Carlo simulations based on density-functional perturbation theory. The free-standing alloy displays a model random behavior, with a miscibility gap below approximately 820 K. In samples grown on a GaAs (001) substrate, the resulting epitaxial strain stabilizes various ordered phases which give rise to a rich phase diagram below approximately 230 K. Among these phases, the chalcopyrite is dominant for x = 0.5, and two new, more complex, stable phases have been identified at different concentrations.
Pedro Miguel Nunes Pereira de Almeida Reis, Michael Christopher Gomez
Athanasios Nenes, Tamar Kohn, Aline Laetitia Schaub, Shannon Christa David, Laura José Costa Henriques