Bonding, Fluctuations and Dynamics in Supercritical Metallic Fluids Using Synchrotron Radiation

使用同步辐射研究超临界金属流体中的键合、波动和动力学

• 批准号: 16340114
• 负责人: INUI Masanori
• 金额: $ 10.5万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16340114/
• 关键词: liquid metal; local structure; dynamic structure; inelastic X-ray scattering; small angle X-ray scattering; X-ray diffraction; liquid semiconductor; supercritical fluid; 静的構造

How are atoms condensed into metals and semiconductors? To understand this important question in solid state physics, we have studied static and dynamic structures for expanded fluid metals and semiconductors using synchrotron radiation at SPring-8. The present results are summarized as below.(1) Liquid and expanded fluid selenium (Se)Using high-resolution inelastic X-ray scattering technique, we found a peculiar narrowing of dynamic structure factor in liquid Se constituted of polymeric molecules. Expanded fluid Se undergoes the nonmetal-metal (NM-M) transition at high temperature and high pressure. We observed a clear increase of small angle scattering intensity in the transition region. At the same time excitation energy of the collective mode disperses twice as fast as the adiabatic sound velocity. These results hint that characteristic fluctuations are generated in the NM-M transition.(2) Short and medium range structures in liquid As_2Se_3Liquid As2Se3 undergoes the NM-M transition at high temperature and high pressure. We observed the increase of small angle scattering intensity but the profile was different from that in expanded fluid Se. Meanwhile no anomaly in the density dependence of the local structure was observed at the NM-M transition.(3) X-ray diffraction measurements of fluid sulfur (S)Nonmetallic liquid S is expanded into the vapor phase without the NM-M transition. We found that the well-separated first coordination shell is preserved in the supercritical region at high temperature and high pressure. Furthermore we observed the density region in which S dimeric molecules may be aggregate to form Si clusters.We plan to investigate the mechanism of the large speed-up of the dynamic sound velocity compared to the adiabatic one observed in the NM-M transition in order to understand deeply the characteristic fluctuations in the NM-M transition.

原子是如何凝聚成金属和半导体的？为了理解固体物理学中的这一重要问题，我们在SPring-8上使用同步辐射研究了膨胀流体金属和半导体的静态和动态结构。目前的结果总结如下。(1)用高分辨非弹性X射线散射技术研究了由高分子组成的液态硒的动力学结构因子。膨胀流体Se在高温高压下发生非金属-金属（NM-M）相变。我们观察到在过渡区的小角散射强度明显增加。同时，集体模的激发能量的色散速度是绝热声速的两倍。这些结果暗示了在NM-M跃迁中产生的特征涨落。(2)液态As_2Se_3的短程和中程结构液态As_2Se_3在高温高压下发生NM-M相变。我们观察到小角散射强度的增加，但轮廓是不同的，在膨胀流体Se。同时，在NM-M跃迁时，没有观察到局域结构的密度依赖性异常。(3)流体硫（S）的X射线衍射测量非金属液体S膨胀到汽相而没有NM-M转变。我们发现，在高温高压下，在超临界区，第一配位壳层保持了良好的分离。此外，我们还观察到了S二聚体分子可能聚集形成Si团簇的密度区域，并计划研究NM-M跃迁中动态声速比绝热声速大幅度提高的机制，以便更深入地理解NM-M跃迁中的特征涨落。

项目成果

Anomalous Cation-Cation Interactions in Molten CuI : ab initio Molecular-Dynamics Simulations

熔融 CuI 中的异常阳离子-阳离子相互作用：从头算分子动力学模拟

• 发表时间: 2004
• 期刊: Journal of the Physical Society of Japan 73(8)
• 作者: F.Shimojo;A.Harada;A.Harada;F.Shimojo;A.Harada;A.Harada;A.Harada;A.Harada;A.Harada;A.Harada;R.Goto;F.Shimojo
• 通讯作者: F.Shimojo

Fast sound in expanded fluid Hg accompanying the metal-nonmetal transition

• DOI: 10.1103/physrevlett.93.097801
• 发表时间: 2004-08-27
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Ishikawa, D;Inui, M;Baron, AQR
• 通讯作者: Baron, AQR

Small angle scattering of supercritical metallic fluids using I high energy X-rays [in Japanese]

使用 I 高能 X 射线进行超临界金属流体的小角度散射 [日语]

• 发表时间: 2006
• 期刊: rournal of Crystallographic Society of Japan 48
• 作者: M.Inui;K.Matsuda;D.Ishikawa;K.Tamura
• 通讯作者: K.Tamura

Dynamics in the melt of an icosahedral Al_72Pd_20Mn_8 quasicrystal

二十面体Al_72Pd_20Mn_8准晶熔体动力学

• 发表时间: 2006
• 期刊: Journal Physics : Condensed Matter 18
• 作者: J.T.Okada;M.Inui;D.Ishikawa;A.Q.R.Baron;K.Matsuda;他4名
• 通讯作者: 他4名

Dynamics in the melt of an icosahedral A172Pd2oMn8 quasicrystal

二十面体 A172Pd2oMn8 准晶熔化动力学

• 发表时间: 2006
• 期刊: J. Phys. : Condens. Matter 18
• 作者: J.T.Okada;M.Inui;D.Ishikawa;A.Q.R.Baron;K.Matsuda;S.Tsutsui;Y.Watanabe;S.Nanao;T.Ishikawa
• 通讯作者: T.Ishikawa