(a) Cladding (GaAs) around a slab (quantum well of , with a larger lattice constant), after a surface has been cleaved but before it has relaxed. The sample occupies the half space with along the direction of growth. (b) Sketch of sample after it has relaxed.
(Color online) Components of stress due to relaxation as a function of depth : (a) and (b) in midplane of well, with (c) at edge of well. The results are shown for the isotropic, cubic aligned, and cubic rotated cases. Stress is measured in units of the fictitious traction and distance in units of the half width .
(Color online) Components of strain due to relaxation as a function of depth : (a) and (b) in midplane of well, with (c) at edge of well. The results are shown for the isotropic, cubic aligned, and cubic rotated cases. Thin lines show strain calculated from the stress for isotropic material using the elastic constants for cubic material in the two orientations. Strain is measured in units of the mismatch and distance in units of the half width .
(Color online) Numerical calculations of outward relaxation of surface using ABAQUS to show the effect of cubic symmetry, orientation, and of assuming that the elastic constants in the slab and cladding are identical. The experimental result from I is also shown. Curves have been shifted vertically to coincide near the edge of the plot because the displacement contains an arbitrary constant.
Effect of symmetry on elastic constants, strain on surface, and prefactor for outward relaxation of surface; in all cases. For comparison, the final row shows the strains deep within the slab.
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