Elastic state and thermodynamical properties of inhomogeneous epitaxial layers: Application to immiscible III‐V alloys

摘要: The elastic strain and stress fields the energy of system composed a crystalline epitaxial layer finite thickness coherently grown on bulk substrate are calculated, when intrinsic stress‐free lattice parameter is modulated along directions parallel to surface. When modulation has components with spatial periods same order as layer, considerably reduced respect occurring in sample. There exists an optimal period elementary sinusoidal modulation, proportional thickness. Consequently, for immiscible alloys where changes composition induce parameter, critical temperature (below which they become thermodynamically unstable modulations) much higher (and domain instability larger) if material form than form. This extends Cahn’s theory spinodal decomposition layers. It also pointed out that started occur growing deformation induced near free surface should have important consequences subsequent growth this layer. These results applied III‐V semiconductors alloys, such In x Ga1−x As y P1−y , modulations known exist. New values temperatures these calculated compared lower former estimates. mode development discussed light previous experimental new calculations.