Extended structural study of gallium melt under pressure

液体ガリウムの高温高圧領域における構造

Yagafarov, O.; 片山 芳則; Brazhkin, V. V.*; Lyapin, A. G.*; 齋藤 寛之

Yagafarov, O.; Katayama, Yoshinori; Brazhkin, V. V.*; Lyapin, A. G.*; Saito, Hiroyuki

We present an energy dispersive X-ray diffraction study of gallium melt in a wide - range (up to 8.5 GPa, 800 K), combined with the reverse Monte Carlo (RMC) modeling. Analysis of the experimental and data shows that anisotropic local structure of liquid Ga deviates from that of a simple hard-sphere-like liquid metal structure. Our data suggests a gradual change of gallium melt to simple hard-sphere-like liquid metal at 15 GPa. Analysis of the RMC modeled atomic configurations supports the view that the liquid gallium structure approaches a simple-liquid-like structure. Analysis of the radial distribution function by a distorted-crystalline model shows that at lower pressures liquid can be described as consisting of two species similar to the solid Ga I and Ga II structures. The fraction of Ga I-like part is about at 0.64 GPa, it gradually decreases under pressure to zero at GPa.