Energy dispersive X-ray diffraction and reverse Monte Carlo structural study of liquid gallium under pressure
高圧下ガリウム液体のX線回折測定及び逆モンテカルロ法による構造観察
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
The structure of liquid gallium has been studied along the melting curve from 0.64 GPa to 5.6 GPa by the energy dispersive X-ray diffraction technique with subsequent modeling of experimental data by the reverse Monte Carlo (RMC) method. Analysis of the structure factor and radial distribution function shows that anisotropic local structure of liquid Ga deviates from the simple hard-sphere-like liquid metal-like. Whereas the 3rd and 4th coordination shell positions and the reverse 1st maximum of demonstrate pressure dependencies close to a uniform compression scaled by the () volume relation, the positions of the 1st (especially) and 2nd coordination spheres have more flat pressure dependencies. At the same time, the first and second coordination numbers increase: the first coordination number starts from 10-10.5 and increases by 5% in the studied pressure interval. This indicates that liquid gallium contraction is non-uniform and the local structure changes with pressure increase. Analysis of the radial distribution function by a distorted-crystalline model shows that at lower pressures liquid consists of two species similar to the solid GaI and GaII structures. The fraction of GaI-like part is about 0.20.05 at 0.64 GPa and gradually decrease under pressure to zero at estimated 7.50.5 GPa.