Investigating the phase transition sequence and thermal diffusion behavior of Ga-In and Ga-Sn liquid metals

The emergence of miniaturization and the high efficiency of power devices has led to the requirements for heat dissipation materials. Gallium-based liquid metal (LM) proposes a potential solution to the heat dissipation problem due to its high thermal diffusion property. However, the impact of the structural evolution of LMs caused by phase transition on thermal diffusion near room temperature remains unclear. Herein, a strategy is introduced to investigate the phase transition sequence in the hypoeutectic, eutectic, and hypereutectic Ga-In and Ga-Sn liquid metals and their thermal diffusion properties. The study highlights these liquid metals' complex phase transition dynamics and non-linear thermal diffusivity properties, mainly influenced by the nanosized n-phase during temperature changes. The precipitation of n-phase significantly enhances the thermal diffusivity during the cooling process with a high thermal diffusivity coefficient. In the heating stage, secondorder phase transitions of n-phase increase phonon and electron scattering in Ga-In and Ga-Sn LMs, causing a decrease in their thermal diffusivity. These results may pave the way for novel approaches to improve the thermal diffusivity of liquid metals.