Melting and High-Temperature Electrical Resistance of Gold under Pressure

Abstract

The electrical resistance of gold was measured over the temperature range 30°C to the melting point and over a pressure range 0-70 kbar. At constant pressure, a sudden twofold increase in resistance sharply indicated the melting point and was used to determine the solid-liquid phase line to 70 kbar. The experimental melting curve has an initial slope, 5.91°C/kbar, in very good agreement with Clapeyron's equation, and has a form satisfying a Simon's equation with a coefficient $c=2.2\mathrm{}\pm 0.1$. The electrical resistance data show a decrease in the temperature coefficient of resistivity at higher pressures, while the resistance at the melting point appears to be a constant independent of pressure.