On the nature of the melting line of bcc sodium

TL;DR

This paper investigates the melting line of bcc sodium at high pressures using first principles molecular dynamics, explaining the observed maximum and subsequent decrease in melting temperature with increasing pressure.

Contribution

It provides a detailed first-principles analysis of sodium's melting behavior under high pressure, clarifying the origin of the maximum in the melting line.

Findings

Identifies the maximum melting temperature at 31 GPa and 1000 K.

Explains the decrease in melting temperature beyond the maximum.

Provides theoretical support for experimental observations.

Abstract

Recent experiments have obtained the melting line of sodium up to pressures of about 130 GPa, finding that the melting line from the {\em bcc} phase reaches a maximum at a temperature of {\em c.a.} 1000 K and a pressure of 31 GPa, and at higher pressures the fusion temperature decreases continuously up to 118 GPa. Here we report results of a study based on first principles molecular dynamics, clarifying the nature of the maximum and subsequent decreasing behavior found in the melting line of sodium.