Formation, structure and properties of fluoro-sulfo-phosphate poly-anionic glasses
Formation, structure and properties of fluoro-sulfo-phosphate poly-anionic glasses
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DOI：
10.1016/j.jnoncrysol.2017.09.043
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发表时间：
2017-12-01
影响因子：
3.5
通讯作者：
Wondraczek, Lothar
中科院分区：
文献类型：
--
作者：
Le, Quyen Huyen;Palenta, Theresia;Wondraczek, Lothar
磷酸盐玻璃对第二阴离子物种表现出高溶解度。这包括硫酸根离子、氟离子或氮离子，并且使得能够制备聚阴离子玻璃。在这里，我们考虑氟磺基磷酸盐。我们表明，在这个系统中，甚至可以实现等摩尔的阴离子混合，而不会显着损害玻璃形成能力。衍生的玻璃表现出令人惊讶的稳定性，这使得大部分批量样品的制造，而不需要采用快速淬火技术。在分子结构方面，它们主要依赖于不同成分之间的离子键合，由此氟离子和硫酸根阴离子似乎充当高度解聚的磷酸盐实体之间的稳定离子交联剂。低频拉曼散射的研究表明，特征变化的中程结构，在玻色子峰的位移似乎与硫酸盐含量的增加成反比。我们讨论了这一观察方面的低水平的键本地化和低场强的硫酸根阴离子相对于磷酸根Q基团。调节阴离子竞争的程度使得能够定制超结构异质性。除此之外，玻璃系统提供了一个有趣的各种配体的情况下，潜在的纳入光学活性阳离子物种。
Phosphate glasses exhibit high solubility for secondary anion species. This includes sulfate, fluoride or nitride ions, and enables the preparation of poly-anionic glasses. Here, we consider fluoro-sulfo-phosphates. We show that in this system, even equimolar anion mixing can be achieved without notably compromising the glass forming ability. The derived glasses exhibit surprising stability, what enables the fabrication of bulk samples mostly without the need to employ rapid quenching techniques. In terms of molecular structure, they rely on primarily ionic bonding among the different constituents, whereby the fluoride and sulfate anions seem to act as stabilizing ionic cross-linkers between highly-depolymerized phosphate entities. Investigation of the low-frequency Raman scattering indicates characteristic variations on intermediate-range structure, where a shift in the Boson peak appears to correlate inversely with increasing sulfate content. We discuss this observation in terms of the low level of bond localization and low field strength of the sulfate anion relative to phosphate Q groups. Adjusting the degree of anion competition enables to tailor super-structural heterogeneity. Beyond this, the glass system provides an interesting variety of ligand situations for the potential incorporation of optically active cation species.