depth profile the surface disorder and possible pressure induced phase transitions.The results indicate that all of the studied compounds were changed due to the compression. The GID analysis shows that the surface regions of the compacted tolbutamide, carbamazepine and chlorpropamide tablets were disordered. The manifestations of the disordering in the diffractographs are the increased peak intensity and height and the decreased peak width. Moreover, a polymorphic phase transition was observed in chlorpropamide tablets. The biggest changes took place at the very surface of the tablets. The transitions were also dependent on the used compaction pressure.The size, shape, strain distribution, compositional profile and spatial distribution are the critical factors determining the electronic level and thus the physical properties of semiconductor nanostructures. For those MBE-grown mesoscopic objects, lattice mismatch, surface segregation, interface diffusion and various kinetic effects make their formation mechanism very complicated. In fact, the structure and the formation mechanism of these self-assembled nanostructures are still not well understood. In this work, we applied grazing incidence X-ray scattering methods including reciprocal space map and small angle X-ray scattering to study the strain field, shape and spatial distribution of III-V semiconductor nano-structures. In particular, we will focus on the application of resonant X-ray scattering technique to accurately determine the compositional distribution within the nano-structures with high resolution.

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