A new UHV diffractometer for surface structure and real time molecular beam deposition studies with synchrotron radiations at ESRF

Abstract

We describe a new surface X-ray diffractometer, which is optimized to combine surface X-ray diffraction (SXRD), absorption spectroscopy (SEXAFS) and grazing incidence small angle scattering (GISAXS). This instrument is particularly well suited for real time studies of material elaborated in-situ with molecular beam deposition (MBD) techniques. The goniometer allows for large in-plane and out-of-plane momentum transfer with high accuracy. Owing to the flipping mechanism of the sample holder, it can perform absorption experiments with polarisation directions normal and parallel to the sample surface, while keeping a grazing incidence. Several MBD sources as well as complementary surface sensitive electron techniques (RHEED and Auger spectroscopy) can be used simultaneously with X-rays. Finally, the samples can easily be inserted in the X-ray chamber via an UHV transport system and a fast entry load-lock module.