The researchers then narrowed down the X-ray beam so that it was just a tenth of a millimetre across and found that the fractal-like regions occurred only where the beam struck the sample.

Then they brought the sample back to room temperature and exposed it to an X-ray beam from the facility while using a CCD detector to record the X-rays reflected from the surface of the sample.

The nanoprobe excites the sample with a strongly focused X-ray beam and collects the characteristic fluorescence signal that is re-emitted.