Computer Coupling of Phase Diagrams CALPHAD ト リンク シタ コウオン ユウタイ ネツ ブッセイ ノ モデリング

研究報

コア シェル ガタ エキテキ ノ カイメン ジユウ エネルギー

研究報

The Variation of Absorption Edges of X-Rays for Liquid Hg-Rb Alloys

The L I and L III edges of Hg and the K edge of Rb in liquid Hg-Rb alloys were measured by the absorption spectroscopy of X-rays. On increasing the Rb concentration, the absorption edges of Hg show an opposite behavior each other, the decrease of L I and the increase of L III compared with the case of pure liquid Hg. This difference was discussed from the polyanion formation of Hg atoms on alloying. With the increase of alkali concentration, the p like state or polyanion seems to be situated on the lower energy side than that of s band. The electronic structure of this polyanion was discussed based on a simple LCAO analysis. Such an existence of polyanions may be responsible to the curious phenomena of liquid Hg-alkali alloys, the maximum of the electrical resistivity at 60 at% alkali and the positively enhanced tendency in the intermediate alkali concentration range of the magnetic susceptibility in the overall negative deviation

Atomic and electronic structures of an extremely fragile liquid

The structure of high-temperature liquids is an important topic for understanding the fragility of liquids. Here we report the structure of a high-temperature non-glass-forming oxide liquid, ​ZrO2, at an atomistic and electronic level. The Bhatia–Thornton number–number structure factor of ​ZrO2 does not show a first sharp diffraction peak. The atomic structure comprises ZrO5, ZrO6 and ZrO7 polyhedra with a significant contribution of edge sharing of oxygen in addition to corner sharing. The variety of large oxygen coordination and polyhedral connections with short Zr–O bond lifetimes, induced by the relatively large ionic radius of zirconium, disturbs the evolution of intermediate-range ordering, which leads to a reduced electronic band gap and increased delocalization in the ionic Zr–O bonding. The details of the chemical bonding explain the extremely low viscosity of the liquid and the absence of a first sharp diffraction peak, and indicate that liquid ​ZrO2 is an extremely fragile liquid