Resistivity, Seebeck coefficient, and thermal conductivity of platinum at high pressure and temperature

Abstract

Platinum (Pt) is one of the most widely used functional materials for high-pressure and high-temperature experiments. Despite the crucial importance of its transport properties, both experimental and theoretical studies are very limited. In this study, we conducted density functional theory calculations on the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of solid face-centered cubic Pt at pressures up to 200 GPa and temperatures up to 4800 K by using the Kubo-Greenwood formula. The thermal lattice displacements were treated within the alloy analogy, which is represented by means of the Korringa-Kohn-Rostoker method with the coherent potential approximation. The electrical resistivity decreases with pressure and increases with temperature. These two conflicting effects yield a constant resistivity of ∼70 μ cm along the melting curve. Both pressure and temperature effects enhance the thermal conductivity at low temperatures, but the temperature effect becomes weaker at high temperatures. Although the pressure dependence of the Seebeck coefficient is negligibly small at temperatures below ∼1500 K, it becomes larger at higher temperatures. It requires a calibration of a thermocouple such as Pt-Rh in high-pressure and-temperature experiments.

Large Power Factors in Wide Band Gap Semiconducting RFeO3 Materials for High-Temperature Thermoelectric Applications

“…In fact, at a hole carrier concentration of 10 21 cm –3 , S values are between 200 to 300 μV/K and the corresponding PF attains its maximum value. Finally, we find that our S results are far better especially those obtained at 10 18 to 10 21 cm –3 than those reported in the previously published works on high-temperature TE materials. , …”

“…Finally, we find that our S results are far better especially those obtained at 10 18 to 10 21 cm −3 than those reported in the previously published works on hightemperature TE materials. 55,56 Electrical conductivity primarily depends on the density and dynamics of the charge carriers. An increasing doping concentration, however, does not necessarily increase σ as can be seen in Figure 4.…”

Thermoelectric properties of elemental metals from first-principles electron-phonon coupling

“…The Seebeck coefficients of Cu, Ag, Au, and Pt have recently been studied by Kou and Akai using the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method, which yields the correct sign with some quantitative discrepancies [27]. The same method was also adopted to predict the behavior of S under high pressure and temperature for Pt [28].…”

Electrical Resistivity of Cu and Au at High Pressure above 5 GPa: Implications for the Constant Electrical Resistivity Theory along the Melting Curve of the Simple Metals

“…The decrease in pressure dependence at ~4 GPa at room temperature also pointed to the cessation of increasing nuclear screening with increasing pressure. At higher pressure above 5 GPa, the similarities in the observed constant resistivity along the melting curves of Pt [ 40 , 49 , 50 ] as well as Fe above ~5 GPa [ 18 ] suggest that partially unfilled late d -band metals could achieve Cu-like filled d -band state through the population of their d -band states by the promotion of s to d electrons through hybridization [ 14 , 15 , 16 , 17 ]. Thus, the constant electrical resistivity along the melting curve could be a universal theory that could be applicable to the transition metals, especially the late ones at higher pressure.…”