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.

Figure 1: Koala Data

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).

Figure 2: Pattern collected from crystals

 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. 

Figure 3: Koala continues probing the practical limits