Validation of the Wiedemann-Franz Law in solid and molten tungsten above
2000 K through thermal conductivity measurements via steady state temperature
differential radiometry
We measure the thermal conductivity of solid and molten tungsten using Steady
State Temperature Differential Radiometry. We demonstrate that the thermal
conductivity can be well described by application of Wiedemann-Franz Law to
electrical resistivity data, thus suggesting the validity of Wiedemann-Franz
Law to capture the electronic thermal conductivity of metals in their molten
phase. We further support this conclusion using ab initio molecular dynamics
simulations with a machine-learned potential. Our results show that at these
high temperatures, the vibrational contribution to thermal conductivity is
negligible compared to the electronic component