Recent results
On Thursday 19 June, the first neutron diffraction experiment using the Koala Laue diffractometer was conducted: the first image was from a crystal of rock salt (NaCl), like the Braggs used for their ground-breaking studies.
Subsequently, a neutron diffraction pattern from a crystal of potassium permanganate (KMnO4) was measured. In a 10 minute exposure the image below was recorded from a 2 x 2 x 2.5 mm3 crystal. The data on this image would have taken about half a day to measure on the decommissioned 2TanA instrument. The structure refinement using the Koala data set was carried out by Chris Ling, University Sydney.
The utility of Koala for the rapid assessment of very large crystals has been demonstrated in the case of the important room-temperature oxide-ion conductor Sr2Fe2O5 (study by Chris Ling, University Sydney).
The pattern below was collected in a 1 minute exposure from the entire width of a 6 mm diameter rod, and confirms that we have grown the first ever large single crystal of this compound by the floating-zone method. The same pattern was reproduced along 25 mm of the rod, i.e., this crystal has a volume of ~ 500 mm3.
Koala continues probing the practical limits of this instrument.