Energy-dispersive X-ray diffraction study of liquid gallium under high pressure at elevated temperatures

Abstract

The structure of liquid gallium has been studied from 340 to 800 K at 4.2(1) GPa by the energy-dispersive X-ray diffraction technique. The analysis of the structure factor S(Q) and the radial distribution function g(r) shows that the anisotropic local structure of liquid Ga deviates from that of a simple hard-sphere-like liquid metal structure. Although the third and fourth coordination shell expansion is consistent with decrease of density in liquid gallium, the positions of the first two coordination spheres oppositely contract. At the same time, the first coordination numbers decrease from ∼10.4 to ∼9.1 in the studied temperature interval. This indicates that both liquid gallium expansion and contraction are non-uniform, and accompanied by the changes of short-range order.