Difference of the powder patterns measured by polarised neutron diffraction on Prussian Blue for the two possible spin states of neutrons. The Bragg peaks labelled in blue reveal the Fourier components of the magnetisation distribution x the amplitude of the nuclear structure factors. From this plot, one can determine the magnetisation distribution in real space at the atomic scale. This measurement reveals the efficiency of the polarised neutron diffraction technique for investigating magnetic interactions in "animal" magnetism.

Submitted by Dr. Eddy LELIEVRE-BERNA of the Institut Laue-Langevin.