Gulay Nataliya L, Zanella Marco, Robertson Craig M, Ritchie Daniel, Sonni Manel, Wright Matthew A, Newnham Jon A, Hawkins Cara J, Whitworth Jayne, Mali Bhupendra P, Niu Hongjun, Dyer Matthew S, Collins Christopher M, Daniels Luke M, Claridge John B, Rosseinsky Matthew J
Department of Chemistry, Materials Innovation Factory, University of Liverpool 51 Oxford Street Liverpool L7 3NY UK
Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool 51 Oxford Street Liverpool L7 3NY UK.
Chem Sci. 2024 Sep 12;15(40):16503-18. doi: 10.1039/d4sc04440a.
Two compounds were discovered in the well-studied BaO-YO-SiO phase field. Two different experimental routines were used for the exploration of this system due to the differences of synthetic conditions and competition with a glass field. The first phase BaY[SiO]O was isolated through a combination of energy dispersive X-ray spectroscopy analysis and diffraction techniques which guided the exploration. The second phase BaY[SiO] was located using iterative algorithmic identification of target compositions. The structure solution of the new compounds was aided by continuous rotation electron diffraction, and the structures were refined against combined synchrotron and neutron time-of-flight powder diffraction. BaY[SiO]O crystallizes in 4̄2, = 18.92732(1), = 5.357307(6) Å and represents its own structure type which combines elements of structures of known silicates embedded in columns of interconnected yttrium-centred polyhedra characteristic of high-pressure phases. BaY[SiO] has 2 symmetry with a pseudo-tetragonal cell ( = 16.47640(4), = 9.04150(5), = 9.04114(7) Å, = 90.0122(9)°) and is a direct superstructure of the CaBaBi[PO] structure. Despite the lower symmetry, the structure of BaY[SiO] retains disorder in both Ba/Y sites and disilicate network, thus presenting a superposition of possible locally-ordered fragments. BaY[SiO]O has low thermal conductivity of 1.04(5) W m K at room temperature. The two discovered phases provide a rich structural platform for further functional material design. The interplay of automated unknown phase composition identification with multiple diffraction methods offers acceleration of the time-consuming exploration of high-dimensional chemical spaces for new structures.
在经过充分研究的BaO-YO-SiO相区中发现了两种化合物。由于合成条件的差异以及与玻璃相区的竞争，使用了两种不同的实验方法来探索该体系。通过能量色散X射线光谱分析和衍射技术相结合的方法分离出了第一相BaY[SiO]O，这些技术为探索提供了指导。第二相BaY[SiO]是通过对目标成分进行迭代算法识别来定位的。新化合物的结构解析借助了连续旋转电子衍射，并且根据同步加速器和中子飞行时间粉末衍射的组合数据对结构进行了精修。BaY[SiO]O以4̄2对称结晶，a = 18.92732(1) Å，c = 5.357307(6) Å，代表其自身的结构类型，该结构类型结合了已知硅酸盐结构的元素，这些元素嵌入以钇为中心的相互连接的多面体柱中，这是高压相的特征。BaY[SiO]具有2对称，具有假四方晶胞（a = 16.47640(4) Å，b = 9.04150(5) Å，c = 9.04114(7) Å，β = 90.0122(9)°），是CaBaBi[PO]结构的直接超结构。尽管对称性较低，但BaY[SiO]的结构在Ba/Y位点和二硅酸盐网络中都保留了无序性，因此呈现出可能的局部有序片段的叠加。BaY[SiO]O在室温下具有1.04(5) W m⁻¹ K⁻¹的低热导率。这两个发现的相为进一步的功能材料设计提供了丰富的结构平台。自动未知相组成识别与多种衍射方法的相互作用，加快了对新结构高维化学空间进行耗时探索的速度。
