Neutron scattering by oxygen gas and the magnetic form-factor of the oxygen molecule

Abstract

Neutron scattering by oxygen gas at 100 bar has been measured. The observed differential cross-section at high Q-values is fitted to a form-factor dependent on the molecular geometry. At lower Q-values there are coherent contributions from intermolecular and magnetic correlations. Molecular dynamics calculations are used to estimate the nuclear part so that the magnetic form-factor can be determined for an isolated molecule. The results for the magnetic form-factor are in satisfactory agreement with the predictions of Kleiner except at very low Q-values.