Heat Transfer in γ-Phase of Oxygen

The isochoric thermal conductivity of γ-O2 has been studied on samples of varying density in the temperature interval from 44 K to the onset of melting. The thermal conductivity of nearly free sample decreases at rising temperature while it increases at isochoric conditions. It is shown that the absolute value of thermal conductivity in the γ-phase of O2 is close to its lower limit and most of the heat is transported by “diffusive” modes. The growth of thermal conductivity in γ-O2 is attributed to the decay of the phonon scattering at the rotational excitations of the molecules and the short-range magnetic order fluctuations at rising temperature.