Micro-SAXS colloidal glasses February 2020

Full description

This archive contains the SAXS data acquired in February 2020 at the SAXS/WAXS beamline Australian Synchrotron by Amelia Liu, Stephen Mudie, Tim Petersen and Rico Tabor.The x-ray beam energy was 5.5 keV. The beam was defined using a near-field gold aperture (25 microns thick and 1.2 micron OD). The specimens were 20 micron thick layers of colloidal glasses composed of SiO2 microspheres (300 nm OD) and sandwiched between two Kapton layers 15 microns in thickness. A Kapton layer was used as the 20 micron spacer. The archive contains:

• Cropped micro-SAXS diffraction patterns (180x180) from spatio-temporal scans (148x21) in .tif format. Each pixel is 6.6e-5 Angstrom^-1.
• The spatio-temporal scans were conducted in 0.5 micron steps. Each line in the x-direction was scanned twice at an interval of 30 s to examine structural variations in each micro-volume with time. Files are named according to this convention 'dp_x_y_t.tif'. The first scan is denoted with t ='a' and the second with a t='b'.
• Diffraction patterns were collected using a Dectris - Pilatus 2M direct detection camera at a camera length of 7244 mm.
• A colloidal glass was scanned before and after a shear strain was applied by drawing a thin copper wire through the glass at a rate of approximately 0.1 mm/s and a distance of 0.2 mm. This would have induced a shear strain in the x-direction that varied linearly with distance from the wire.
• An area below the wire was scanned. Please see the file geometry.pdf to see the geometry of the applied strain with respect to the scan directions.
• Scanned areas were chosen where the glass thickness was homogeneous, visible fibres/dust etc could not be seen, and the beam intensity was stable.