Heat transfer in gama-phase of oxygen

TL;DR

This study investigates the thermal conductivity of gamma-phase oxygen across various densities and temperatures, revealing that heat is mainly transported by diffusive modes and that conductivity increases due to reduced phonon scattering.

Contribution

It provides new insights into heat transfer mechanisms in gamma-phase oxygen, highlighting the role of molecular rotational excitations and magnetic fluctuations.

Findings

Thermal conductivity decreases with temperature along isochores.

Conductivity is close to its lower limit, dominated by diffusive modes.

Increase in conductivity linked to decay of phonon scattering.

Abstract

The isochoric thermal conductivity of gama-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 along the isochores. It is shown that the absolute value of thermal conductivity in the gama-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 gama-O2 is attributed to the decay of the phonon scattering at the rotational excitations of the molecules and at the short-range magnetic order fluctuations at rising temperature.