The X-ray Diffraction Unit gathers all the techniques which are based on the diffraction of X-rays on crystalline solids. It gives support in the characterisation of chemical compounds which are available in a crystalline state.
Two principal techniques are available: Powder X-ray Diffraction (PXRD) and Single Crystal X-ray Diffraction (SCXRD).
The PXRD technique is used basically as a primary screening method and delivers a finger print of each different crystalline form analysed. This method gives a basic service to all users at the ICIQ with a system which allows easy sample preparation and short measuring time for a high number of samples.
The SCXRD technique delivers a three-dimensional structure at atomic scale of a selected crystalline compound. This method is highly specialised with a system fitted together from high performance components. The objective in this case is to give a direct support to the research groups solving problems in all levels of difficulty. This support includes the crystallization of problematic samples, the preparation of crystals of poor quality and the refinement of troubling datasets.
Powder X-ray diffraction system
D8 Advance Series 2Theta/Theta powder diffraction system using CuKa-radiation in transmission geometry. The system is equipped with a VÅNTEC-1 single photon counting PSD, a Germanium monochromator, a ninety positions auto changer sample stage, fixed divergence slits and a radial soller. Programs available: Data collection with DIFFRAC plus XRD Commander V.2.4.1 and evaluation with EVA V.12.0. and TOPAS V.6.
Single crystal X-ray diffraction system
Bruker-Nonius diffractometer equipped with a APPEX 2 4K CCD area detector, a FR591 rotating anode with MoKalpha radiation, Montel mirrors as monochromator and a Kryoflex low temperature device (T = 100 K). Programs available: Data collection Apex2 V. 1.0-22 (Bruker-Nonius 2004), data reduction Saint+ Version 6.22 (Bruker-Nonius 2001) and absorption correction SADABS V. 2.10 (2003). Crystal structure solution and refinement as implemented in SHELXTL Version 6.10 (Sheldrick, Universtität Göttingen, Germany, 2000). Refinement also with the Multipol Refinement Programm XD 4.1.