Magnetic structure of solid oxygen

Neutron powder patterns of solid α- and β-oxygen have been taken. Comparison with x-ray and electron-diffraction patterns shows that α-oxygen is antiferromagnetic whilst β-oxygen is not. For the β phase there is strong evidence from the present neutron-diffraction data and from susceptibility measurements that the magnetic moments are not randomly aligned but that they exhibit shortrange antiferromagnetic order. The magnetic structure of the α phase is commensurate with the lattice since the two observed magnetic lines have d spacings of twice the value for the nuclear lines, but the absence of an established atomic structure precludes detailed discussion of the magnetic order.