Relaxation of crystal lattice parameters and structural ordering in InxGa1-xAs epitaxial alloys

Epitaxial InxGa1-xAs/GaAs(100) heterostructures grown by the MOC-hydride method with a considerable lattice mismatch are studied by X-ray diffraction and scanning electron microscopy. The relaxation coefficient of the crystal lattice of the epitaxial alloy is calculated and the deformation energy is evaluated. It is shown that, at a concentration of the In atoms in metal sublattice close to x = 0.5, the superstructural phase formed on the surface of the epitaxial InxGa1-xAs alloy is the InGaAs2 compound with a layered tetragonal crystal lattice and ordered arrangement of the atoms of the metal sublattice in the growth plane of the epitaxial film.