Mixed alkali environment in chalcohalide glasses for optical applications

Heavy alkali halide sulphide and selenide glasses are promising hosts for active and passive optical devices. Lithium and sodium chalcohalide glasses exhibit high ionic conductivity and can be used for battery applications. The atomic structure of these glasses is extensively studied using spectroscopic techniques but the diffraction studies are rare. Recently, we have used a combination of neutron and high-energy x-ray diffraction to unveil the short and intermediate range order in NaCl-Ga2S3-GeS2 glasses. Surprisingly, the sodium tetrahedral environment in these glasses appears to be mixed with Na-Cl and Na-S neighbours. This structural information has never mentioned in available literature and allows a new insight into atomic structure of these practically important chalcohalide glasses. Consequently, we aim to investigate whether the mixed alkali environment exist for K and Rb

重碱金属卤化物硫化物与硒化物玻璃（Heavy alkali halide sulphide and selenide glasses）是制备有源与无源光学器件的极具应用潜力的基质材料。锂硫卤玻璃与钠硫卤玻璃具备优异的离子电导率，可应用于电池领域。目前学界已通过光谱技术对这类玻璃的原子结构开展了广泛研究，但相关衍射研究却较为匮乏。近期，我们团队采用中子与高能X射线衍射（neutron and high-energy x-ray diffraction）联用技术，解析了氯化钠-硫化镓-硫化锗玻璃的短程与中程有序（short and intermediate range order）结构。令人意外的是，这类玻璃中钠的四面体配位环境同时存在Na-Cl与Na-S配位邻近原子。该结构信息在现有文献中尚未见报道，为理解这类具有实际应用价值的硫卤玻璃的原子结构提供了全新视角。基于此，我们计划探究钾（K）与铷（Rb）体系中是否同样存在混合碱金属配位环境。