Crystallography station

This station is used for crystallographic measurements.
The source is a Rigaku RA007 with Cu anode target and has two branches.
Each of the branches has a Rigaku Confocal Max-Flux® optic, combining two Max-Flux® graded multilayer optics to focus in two dimensions and monochromatize the beam.

Fig 1: Rigaku Confocal Max-Flux® optic

Fig 2: Rigaku Osmic Crystals


The Bragg-Brentano branch is equipped with a 8 axis Huber diffractometer station and a scintillator detector, and is mainly used for powder diffraction measurements. Its system of axes can provide 1) the typical ω-2θ scan, 2) tilting of the sample (ψ angle) for stress and strain measurements, and 3) φ angle rotation for texture measurements. The 2θ axis is equipped with a 250mm vacuum pipe (10-2 mbar) in order to suppress noise and reduce the air absorption of the diffracted signal.
The whole diffractometer setup can be precisely aligned to the X-ray probe by means of a set of translation and rotation motors can move the whole setup.
Powder diffraction samples are prepared in flat plate configuration, and mounted on circular sample holders or in capillar glasses. Sample holders can be mounted in a fixed or in a rotating support. The circular sample holder is designed to be used also in the MCX beamline.
It is possible to mount custom cells or device for custom measurements. Please refer to the lab staff for any questions, queries or doubts. Ad-hoc supports and/or sample holders can be custom-made upon suitable notice.
The instrumental profile (Caglioti's equations) is periodically calculated with a LaB6 NIST 660a powder sample.


Fig 3: 8 axis Huber diffractometer                    Fig 4: Pinole & 250mm vacuum pipe

XRF instrumentation is also available (Amptek XR-100T photodiode + Amptek MCA800D) for chemical speciation of the samples (up to Z = 28).

Fig 5: Amptek XR-100T photodiode for XRF technique

The second branch uses a Rigaku R-Axis 4 ++ Image Plate (owned by the university of Roma 3) and is specifically designed for rapid diffraction measurement from single crystal samples. The system is able to handle samples ranging from small molecule crystals to protein crystals (macromolecular crystals).
The 200 mm
2 image plate can be read in about 8 minutes, with a detection sensitivity of about 1 X-ray photon/ pixel.
Measurements are conducted either with a rotating capillary, or in grazing incidence.

Fig 6: Rigaku R Axis 4++ Schematic



Last Updated on Monday, 25 January 2021 16:55