Chain dependent crystal chemistry and temperature-dependent properties of mullite-type related materials with stereo-chemically active lone electron pairs

该项目提供了用两种不同构型的链比较地研究它们各自很少被研究的矿物类似物的合成单八面体链无机材料的可能性。这包括改进它们的晶体结构，确定相应的物理化学性质，以及结构-性质相关性随温度的变化。这类化合物的研究将是交叉连接无机晶体化学、结晶学和矿物学的一个有价值的发展。该项目的主要主题是与已知的具有单电子对元素的莫来石类型相关的新化合物的形成和晶体化学研究。感兴趣的结构主要是α-和β-PbMBO4或化学扩展。由于我们已经发展了一个相当强大的德拜-爱因斯坦-非谐性(DEA)微观模型来描述热膨胀，基于Mie-Grüneisen近似，可以用随温度变化的红外、拉曼和UV/VIS光谱测量来比较声子能量和相应的声子行为。另一方面，声子行为将使用DFT计算，这是与我们的阿根廷合作伙伴合作进行的。

The project offers the possibility to comparably investigate synthetic single octahedral-chain inorganic material of their respective rarely investigated mineral analogues with chains in two different configurations. This includes the refinement of their crystal structures and the determination of the corresponding physico-chemical properties together with temperature-dependent changes of the structure-property correlation. The investigation of such compounds would be a valuable development for the cross-connecting inorganic crystal chemistry, crystallography and mineralogy. The main topics of the project are the formation and crystal chemical investigation of new compounds related to known mullite-types with lone-electron pair elements. Structures of interest are mainly α- and β-PbMBO4 or chemical extensions. As we have developed a quite powerful Debye-Einstein-Anharmonicity (DEA) microscopic model to describe the thermal expansion, the phonon energy and the corresponding phonon behavior could be compared, based on the Mie-Grüneisen approximation, with temperature-dependent infrared and Raman and UV/Vis spectroscopic measurements. On the other hand the phonon behavior will be calculated using DFT calculations, carried out in cooperation with our Argentinian partner.