  We present a detailed x-ray diffraction study of the strain in InAs/GaSb
superlattices grown by molecular beam epitaxy. The superlattices were grown
with either InSb or GaAs interfaces. We show that the superlattice morphology,
either planar or nanostructured, is dependent on the chemical bonds at the
heterointerfaces. In both cases, the misfit strain has been determined for the
superlattice layers and the interfaces. We also determined how the magnitude
and sign of this strain is crucial in governing the morphology of the
superlattice. Our analysis suggests that the growth of self-assembled
nanostructures may be extended to many systems generally thought to have too
small a lattice mismatch.
