The ID03 Surface Diffraction Beamline was open to users' activity in 1993. Since then it has given the possibilities of carrying out a considerable number of experiments that resulted in an important number of publications. Following the indications given by the ESRF Scientific Advisory Commitee on November 2004, a refurbishment programme of the ID03 beamline was decided in order to maintain its role as the center of gravity of Surface Diffraction community. Consequently, the following upgrades have been suggested:

  • An upgrade of the LN2 cooling scheme of the monochromator crystals. This is a high priority to allow the beamline to fully benefit from the ID03 undulators brightness.
  • Optimization of the focusing system by improving the existing KB and double mirror system.
  • Increase of the size of the first experimental hutch (EH1) by the merging of the existing EH1 and EH2.
  • Size increase of the EH1 diffractometer as a second step.
  • Installation of a new downstream hutch of convenable size for the present UHV diffractometer and for hooking up user systems.
  • Modernisation of the UHV diffractometer presently operational in EH2. The modernisation basically consists in the installation of a sample load lock and in disanchoring the UHV system cradle from the basic geometric tables and detector system. This will fulfil the Surface and Interface Science community requests of having the possibility of installing user owned UHV systems and in simplifying the sample exchange.

The ID03 beamline has been closed to the users' activities in July, 2005 and is back in operation since June 2006.


The Surface Diffraction Beamline is devoted to structural and dynamical studies of surfaces and interfaces by investigating the diffracted intensities from ordered overlayers or substrate atoms.

The main components of the Beamline are:

  • A Si(111) double crystal monochromator with sagittal focusing achieved by bending the second crystal.
  • Two flat Rh-coated Si mirrors to reject harmonics (<10-4).
  • A first experimental hutch (EH1) equipped with a z-axis diffractometer with its main sample axis vertical, specially suited for horizontal sample surfaces. On the diffractometer it is possible to mount "baby chambers" of a maximum weight of 50 kp. and small cells for solid/liquid or electrochemistry experiments.
  • A UHV/high pressure chamber equipped with an ion gun for sample cleaning, a mass spectrometer and a sample holder that allows to heat the crystals to 1200 K. The chamber base pressure is 1x10 -9 mbar and the maximum pressure is 4 bar. This chamber can be mounted on the vertical diffractometer.
  • A second experimental hutch (EH2) equipped with a z-axis diffractometer with its main sample axis along the horizontal. Coupled to this diffractometer there are two Ultra-High-Vacuum chambers one for sample introduction and the other for analysis. In the last one several K-cells or e-beam cells can be installed for UHV deposition . Also, the sample can be heated up to 1200 K and cooled to 55 K. A Cylindrical Mirror Analyser allows to record Auger spectra in the diffraction position and an ion gun allows to clean the samples.
  • The standard detectors are scintillator point detectors. In both diffractometers an analyser crystal is installed to reduce background. The scattering plane of the analyser can be vertical or horizontal which is useful for polarization analysis of the diffracted beams. Also, a CDD detector can be installed in the detector arm of the horizontal axis diffractometer.

Scientific Applications

Surface X-ray diffraction is a well-established technique for structural studies of surfaces. Presently it is one of the major techniques of surface crystallography together with electron-based techniques such as LEED (Low Energy Electron Diffraction) or photoelectron diffraction. At variance with these, in which the very short (few Angstroms) mean free path of the electrons necessitates a vacuum environment, X-rays (specially at relatively high energies) are also very well suited for non vacuum studies due to their much higher penetration depth compared to electrons. As a consequence, buried solid interfaces, solid/liquid interfaces and high pressure gas/solid interfaces are well adapted to the technique.

In addition to crystallographic studies, surface diffraction is also suited to dynamical studies such as epitaxial growth, ion patterning, surface kinetics and phase transitions. In particular, ion erosion with ion beams in combination with grazing-incidence small-angle scattering has been employed to study the dynamical evolution of medium range correlations during nanopattering.

Another important application of interest is the magnetic aspect of the technique. Under resonant scattering conditions, in which intense dipolar transitions are excited, the atomic diffusion factor is sensitive to the magnetization of the resonant atoms. This important physical phenomenon is exploited to investigate surface magnetism. The so called Magnetic Crystal Truncation Rods allow us to find the depth distribution and magnetization of the resonant atoms.

Techniques Available

In addition to Surface X-ray Diffraction here is a list of ancillary available techniques and instruments.

  • Auger Electron Spectroscopy
  • RHEED (Reflection High Energy Electron Diffraction)
  • MOKE (Magneto-Optical Kerr Effect)
  • Ion gun
  • Evaporators: Knudsen cells and electron bombardment evaporators

Complementary Information