Determination of Structural Correlations in Amorphous Materials by Means of Synchrotron- and Neutron Scattering and Reverse Monte-Carlo-Simulations

通过同步加速器和中子散射以及逆蒙特卡罗模拟确定非晶材料中的结构相关性

• 批准号: 418865882
• 负责人: Professor Dr. Wolf-Christian Pilgrim
• 金额: --
• 依托单位: Fachgebiet Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/418865882?language=en
• 关键词: Determination; Structural; Correlations; Amorphous; Materials

Main results during the first funding period were the successful further development of a Reverse Monte Carlo simulation program (RMC) for disordered molecular systems and new data reduction software for the correction of X-ray scattering data to absolute values. In connection with high-precision X-ray scattering data made accessible with these developments, but also with EXAFS data, the RMC provided first impressive structural results for one amorphous White Light Generator (WLG) and one macroscopic amorphous Second-Harmonics Generator (SHG) each synthesized in the research group. The limitation to only two systems so far is a consequence of the Corona pandemic on the one hand, but also of the misjudgment of the manpower needed for our research work in the first funding period.In the second funding period, the tools now available will be applied to additional organic and inorganic WLGs to identify structure-property relationships that can explain the limitation of this effect to just amorphous materials. Experimentally, the studies will also be more extended more to neutron scattering experiments to understand the correlations between the organic ligands.Recent results also suggest the existence of a sulfur network in the {Sn4S6}-WLGs, which could be interpreted as a vibrational network. Inelastic neutron scattering experiments will be performed to clarify this. So-called excess vibrational densities of states in amorphous systems are however well known for long (Bose peak). This question will be addressed here as well.

在第一个资助期内的主要成果是成功地进一步开发了无序分子系统的反向蒙特卡罗模拟程序（RMC）和用于将X射线散射数据校正为绝对值的新数据简化软件。结合这些发展提供的高精度X射线散射数据以及EXAFS数据，RMC首次为研究小组合成的一个非晶白色光发生器（WLG）和一个宏观非晶二次谐波发生器（SHG）提供了令人印象深刻的结构结果。到目前为止，只有两个系统的局限性，一方面是电晕流行病的后果，但也是由于我们在第一个资助期内的研究工作所需的人力的误判。在第二个资助期内，现有的工具将被应用于额外的有机和无机WLG，以确定结构-性质关系，可以解释这种影响的局限性，只有无定形材料。在实验上，研究也将更多地扩展到中子散射实验，以了解有机配体之间的相关性。最近的结果也表明，在{Sn 4S 6}-WLGs中存在硫网络，这可以被解释为振动网络。将进行非弹性中子散射实验来阐明这一点。然而，非晶系统中所谓的过量振动态密度（玻色峰）是众所周知的。这个问题也将在这里讨论。