Wilson Mark
Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
J Phys Condens Matter. 2016 Dec 21;28(50):503001. doi: 10.1088/0953-8984/28/50/503001. Epub 2016 Oct 25.
The study of the structure and dynamics of network-forming materials is reviewed. Experimental techniques used to extract key structural information are briefly considered. Strategies for building simulation models, based on both targeting key (experimentally-accessible) materials and on systematically controlling key model parameters, are discussed. As an example of the first class of materials, a key target system, SiO, is used to highlight how the changing structure with applied pressure can be effectively modelled (in three dimensions) and used to link to both experimental results and simple structural models. As an example of the second class the topology of networks of tetrahedra in the MX stoichiometry are controlled using a single model parameter linked to the M-X-M bond angles. The evolution of ordering on multiple length-scales is observed as are the links between the static structure and key dynamical properties. The isomorphous relationship between the structures of amorphous Si and SiO is discussed as are the similarities and differences in the phase diagrams, the latter linked to potential polyamorphic and 'anomalous' (e.g. density maxima) behaviour. Links to both two-dimensional structures for C, Si and Ge and near-two-dimensional bilayers of SiO are discussed. Emerging low-dimensional structures in low temperature molten carbonates are also uncovered.
本文综述了网络形成材料的结构与动力学研究。简要介绍了用于提取关键结构信息的实验技术。讨论了构建模拟模型的策略,包括针对关键(实验可获取)材料以及系统控制关键模型参数。作为第一类材料的示例,以关键目标体系SiO为例,说明如何有效地(在三维空间中)模拟外加压力下结构的变化,并将其与实验结果及简单结构模型相联系。作为第二类材料的示例,通过与M - X - M键角相关的单一模型参数来控制MX化学计量比中四面体网络的拓扑结构。观察到多长度尺度上有序化的演变以及静态结构与关键动力学性质之间的联系。讨论了非晶硅和SiO结构之间的同构关系以及相图中的异同,后者与潜在的多晶型和“异常”(如密度最大值)行为相关。还讨论了与C、Si和Ge的二维结构以及SiO近二维双层结构的联系。同时也揭示了低温熔融碳酸盐中新兴的低维结构。