| In the development of the technology of new narrow bandgap engineered materials, X-ray studies provide a non-destructive, accurate and quantitative method for the structural determination of the new materials. In this work, two novel systems have been characterized by 4-circle X-ray diffractometry. The first system is the {dollar}rm Insb{lcub}x{rcub}Gasb{lcub}1-x{rcub}Sb/InAs{dollar} strained-layer superlattice grown by MBE on a GaSb (001) substrate. This system, proposed by Maliot and Smith (1987) for IR detection application, is challenging because of the two group V species and the likelihood of cross-incorporation of the different elements during growth, leading possibly to interdiffusion and thus to a more diffuse interface. High-resolution X-ray diffraction (XRD) profiles were obtained about several reciprocal lattice points in order to extract a reliable set of structural parameters. The profiles were then modeled by computer simulation with very good agreement. The presence of many sharp higher-order satellite reflections in the XRD profiles is a measure of the high quality of the superlattices. The normal and lateral structural coherence was also measured and will be discussed. The second system is the semiconductor-semimetal heterostructure of GaSb/Sb, which has received increasing attention due to the unique phenomena derived from the combination of the electronic properties of the two materials. The structural quality and the order have been determined establishing the good growth and high quality of the heterostructures thus making the system a potential candidate for a multilayer structure. |
