Melting curve of iron up to 3600 kbar by statistical moment method

The inner core of the earth is solid, the outer liquid is composed mainly of iron, and the pressure at the inner core boundary (ICB) is 3300 kbar (330 GPa). The melting point of iron at ICB limits the thermal structure and solidification of the earth’s core. Current estimates of the melting temperature of iron in the earth’s inner core boundary conditions vary considerably. Here, we have used the Lindemann criterion for melting and the statistical moment method, obtained the melting curve of iron up to 3600 kbar, which is in good agreement with most recently published experimental and theoretical curves. We calculated the melting temperatures of iron at the mantle boundary (1350 kbar) and inner core boundary (3300 kbar) to be 4017 and 6191 K, respectively. In particular, the equation of the melting curve of iron that we calculated has a simple form, which is easy to calculate and verify. This equation can be used to predict the melting temperature of iron up to 3600 kbar with reliable accuracy but very simply. It can also be used to predict the pressure when the melting point of iron is known. Graphic Abstract