MAGNETIC DYNAMICS IN THE DISORDERED PHASES OF CONDENSED OXYGEN

A high-resolution inelastic neutron scattering study of the liquid and plastic crystal phases of oxygen is presented. The separation of the magnetic response from the total cross sections is achieved by means of a computer molecular dynamics simulation which enables an approximate estimation of the magnetic spectral weight functions. The magnetic dynamics of the orientationally disordered plastic crystal is shown to exhibit a characteristic behaviour corresponding to an exchange-coupled paramagnet. The magnetic response of the liquid phase retains the most salient characteristics of the rotationally disordered solid phase.