The LiF–BeF2 system is used as a heat transfer medium in molten salt reactors (MSRs). The thermal diffusivity of Li2BeF4 was studied using the laser flash analysis (LFA) method in solid and transition states. While the thermal diffusivity is shown to decrease slightly in solid-state Li2BeF4, it drops significantly at temperatures close to phase transition. The heat capacity of Li2BeF4 was measured by differential scanning calorimetry (DSC). Some differences were observed between the results obtained in cooling and heating modes. Thermal conductivity was calculated using thermal diffusivity-, density-, and heat-capacity data. The good thermal conductivity of the Li2BeF4 compound in solid and liquid states justifies its use as a heat transfer medium for molten salt reactors.
