In this work, we present a comprehensive first-principles study of liquid lead (Pb) properties at high temperatures, with emphasis on the near-critical region. Using ab initio molecular dynamics combined with density functional theory, we systematically investigate the thermodynamic properties of lead, including thermal expansion, enthalpy, isochoric and isobaric heat capacities, the Grüneisen parameter, and the speed of sound at expansions up to 45 times. Self-diffusion and dynamic viscosity coefficients along the critical isobar are also presented. Some analytical approximations are provided to facilitate practical applications. We provide equation-of-state data for liquid and fluid expanded lead, significantly advancing the understanding of its behavior in the region of parameters practically unattainable by theoretical and experimental methods. The critical point parameters are determined to be $T_c=5.46\pm 0.10$ kK, ${\rho }_c=1.8\pm 0.3 {\mathrm{g}/\mathrm{cm}}^3$, and $P_c=0.8\pm 0.2$ kbar, with a critical compressibility factor $Z_c=0.20\pm 0.06$. We confirm a sharp threefold drop in dynamic viscosity between 600 and 1500 K and reveal a slow decrease at temperatures of 1500–5400 K. These findings are of fundamental importance for condensed matter physics and can be applied for the design of power plants with lead coolant.

Close

PrevNext

View figure in article

• Liquid-gas phase transition
• Phase diagrams
• Specific heat
• Thermal properties
• Thermodynamics
• Liquid metals
• Transition metals
• Ab initio molecular dynamics
• First-principles calculations