Activities The scientific activity of laboratory NRS is mainly directed on the one hand towards the study in-situ, under ultra vacuum, in real time, of the growth, ripening and the car organization of nanostructures and on the other hand towards the structural study ex-situ of nanostructures. With this intention we develop competences around techniques based on the use of the X-radiation of laboratory and synchrotron. The X-radiation constitutes a probe, nondestructive, which produces statistical data and makes it possible for example to analyze in-situ nano-objects in the course of growth, or ex-situ on the surface or buried. Moreover the brightness, the polarization and the accordability in energy of the synchrotron radiation are very largely single characteristics misent with profit (anomalous diffraction, absorption X). Information collected relates to the forms, faceting, the sizes and their distributions, the stress fields, the composition, the atomic structure at short distance... A significant share of our activity is dedicated to construction, the their intruments and maintenance and line control CRG (Collaborative Research Group) French to ESRF (BM32, FAME and DÀM). We accomodate the researchers on the intruments of these lines for experiments coming under our responsibility (Diffraction in-situ, Absorption X, anomalous Diffraction, Spectroscopie in condition of diffraction).
Examples of studies in progress - Study ex-situ of the form, cuts, constraints and composition of buried nanostructures: As/InP wire, boxes and superréseau of GaN/AlN boxes. - in situ Study of the car organization of metal particles: Co/Au(111), Co on networks of dislocations emerging on the area of film Ag, Co on substrate of W nano-faceted. - Study by absorption X of the localization and the local environment of the atoms mn and Have in the GaN/AlN heterostructures - Simulations of the stress fields and the intensities diffused with small and great angles of shaving incidence, and for energies of beam X close relations of the thresholds of absorption.
External collaborations - CEA-Saclay DRECAM/SPCSI : Etude RS in situ de la reconstructions de SiC ; GPS, Université Paris VI : auto-organisation. GPS, LURE, Orsay, surfaces vicinales ; LMCP, GPS : metal/oxydes ; Université de Piscataway: nanostructuration de surface. - Institut d'Electronique, de Microélectronique et de Nanotechnologie, Villeneuve d'Ascq : simulations des champs de déformations ; ICMA, CSIC-Université de Zaragoza, Madrid : GI-DAFS et absorption X, nanostructures InAs/InP.
Techniques mainly used - Diffusion with the small angles of shaving incidence, under ultra vacuum (GISAXS), BM32, ESRF - Diffusion with the great angles of shaving incidence, under ultra vacuum (GIXD), BM32, ESRF - anomalous Diffraction and Spectroscopy in condition of diffraction in shaving incidence (GIDAFS), BM2, BM32, ID1, ESRF - Absorption X (FAME, ESRF) - Diffraction in laboratory: a rotating anode and a diffractometer adapted to measurement in shaving incidence. Instrumental developments - Micro focusing of the synchrotron radiation (French lines CRG), GIDAFS applied to the study of nanostructures.
Maj : 20/02/2017 (260)