Phase separation and atomic ordering in InAsSb epitaxial layers grown by molecular beam epitaxy

InAs0.5Sb0.5 epitaxial layers were grown by molecular beam epitaxy at 370 degrees C on the three types of GaAs substrates with different misorientations: exact (001), 3 degrees off toward [110] and 3 degrees off toward [ITO]. Transmission electron microscope and transmission electron diffraction studies showed that phase separation occurred resulting in plates lying approximately parallel to the layer surface and that CuPt-type atomic ordering also occurred during growth. The morphology of the phase-separated plates was found to depend on different substrate misorientations. TED results showed that CuPt type atomic ordering was a;iso affected by the steps associated with misorientations.