Grazing-incidence diffraction anomalous fine structure of InAs/InP(001) self-assembled quantum wires

We have studied nanostructured samples of InAs/InP(001) by means of Grazing Incidence Diffraction Anomalous Fine Structure. The samples, grown by molecular beam epitaxy, show a periodic corrugation on the surface giving rise to an array of self-assembled quantum wires after deposition of 2.5 monolayers of InAs. We measured the ( 440) and ( 420) GIDAFS spectra, at the As K-edge, at incidence and outgoing angles close to the substrate's critical angle. We analysed the anomalous diffraction lineshapes vs. the energy, as well as the oscillatory part of the signal in the extended region above the edge and obtained, for the first time, information about composition and strain inside the quantum wires and close to the interface. Our results suggest possible interfaces.