Asymmetrical bonding in liquid Bi disentangled by inelastic X-ray scattering
Asymmetrical bonding in liquid Bi disentangled by inelastic X-ray scattering
复制标题
非弹性 X 射线散射解开液态 Bi 中的不对称键合
DOI：
10.1051/epjconf/201715106001
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Baron Alfred Q. R.
中科院分区：
文献类型：
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作者：
Inui Masanori;Kajihara Yukio;Munejiri Shuji;Hosokawa Shinya;Chiba Ayano;Ohara Koji;Tsutsui Satoshi;Baron Alfred Q. R.
由于晶体 Bi 采用 A7 结构，因此液态 Bi 的结构与 Peierls 畸变的关系一直存在争议。最近对液体 Bi 的初始分子动力学模拟预测了声色散曲线的平顶轮廓。为了证实这一预测，我们对液态 Bi 进行了非弹性 X 射线散射（IXS）。 IXS获得的动态结构因子在14 nm−1处表现出明显的纵向声模非弹性激发，并且通过记忆函数分析获得的激发能量的色散曲线变成平顶曲线。我们发现，包含与第二近邻的原子间相互作用的线性链模型可以解释平顶轮廓。结果表明，液态 Bi 中的反常色散曲线是由与结晶相 Peierls 畸变相关的局部各向异性引起的。 。
The structure of liquid Bi has been debated in relationship with the Peierls distortion, as crystalline Bi takes A7 structure. A recentab initiomolec- ular dynamics simulation for liquid Bi predicted a flat-topped profile of the acoustic dispersion curve. To confirm the prediction, we have carried out inelas- tic x-ray scattering (IXS) for liquid Bi. The dynamic structure factor obtained by the IXS exhibits a distinct inelastic excitation of the longitudinal acoustic mode up to 14 nm−1and the dispersion curve of the excitation energy obtained by the memory function analysis becomes a flat-topped one. We found that a linear chain model including the interatomic interaction with the second near- est neighbors can explain the flat-topped profile. The result suggests that the anomalous dispersion curve in liquid Bi arises from local anisotropy related to the Peierls distortion in the crystalline phase. .