Zinc coordination environment in zinc silicate glass

The coordination environment of zinc along the ZnO-SiO2 tie-line will be investigated by high real-space resolution neutron diffraction. The samples will be prepared by aerodynamic levitation with laser heating. The glass compositions will range from the silica poor 33 mol% orthosilicate, where there is insufficient silica to form a network, to a silica rich 70 mol%. The strategy is to maximise change to the Zn-O coordination number, which can vary from 4 to 6, i.e., Zn has the capability to transform its identity from a network former to a network modifier. The results will provide unambiguous information on the nature of the local Zn-O coordination environment to aid in the development of realistic atomistic models. The results will also provide benchmarks for establishing the structure of the functional glasses that are created by the addition of network formers such as Al2O3.

本研究将采用高实空间分辨中子衍射技术，探究ZnO-SiO₂相图结线上锌的配位环境。实验样品通过气动悬浮激光加热法制备。玻璃组分范围覆盖从贫硅的33摩尔%原硅酸盐（此时二氧化硅不足以形成玻璃网络）至富硅的70摩尔%原硅酸盐体系。本研究的核心策略为最大化调控Zn-O配位数的可调范围，其取值可在4至6之间变化，即锌可实现从网络形成体（network former）到网络修饰体（network modifier）的身份转变。研究结果将提供关于局部Zn-O配位环境本质的明确信息，助力构建精准的原子级模型；同时也将为通过添加Al₂O₃等网络形成体制备的功能性玻璃的结构表征提供基准参照。