Electronic Structure from Polarised Neutron Diffraction

Abstract

The polarised neutron diffraction experiment is described and the nature of the information obtained is outlined. In many cases interpretation of the experiment assumes that the crystal is made up of non-interacting molecular or ionic units. The soundness of this assumption is examined in the case of copper Tutton salt. Polarised neutrons are scattered by the crystal magnetisation density which has a contribution from the orbital motion of electrons. A method for including the spin-orbit contribution to this effect is described for the particular example of the CoCI²₄⁻ ion.