Two compounds were discovered in the well-studied BaO–Y₂O₃–SiO₂ 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 Ba₅Y₁₃[SiO₄]₈O_8.5 was isolated through a combination of energy dispersive X-ray spectroscopy analysis and diffraction techniques which guided the exploration. The second phase Ba₃Y₂[Si₂O₇]₂ 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. Ba₅Y₁₃[SiO₄]₈O_8.5 crystallizes in I2m, a = 18.92732(1), c = 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. Ba₃Y₂[Si₂O₇]₂ has P2₁ symmetry with a pseudo-tetragonal cell (a = 16.47640(4), b = 9.04150(5), c = 9.04114(7) Å, β = 90.0122(9)°) and is a direct superstructure of the Ca₃BaBi[P₂O₇]₂ structure. Despite the lower symmetry, the structure of Ba₃Y₂[Si₂O₇]₂ retains disorder in both Ba/Y sites and disilicate network, thus presenting a superposition of possible locally-ordered fragments. Ba₅Y₁₃[SiO₄]₈O_8.5 has low thermal conductivity of 1.04(5) W m⁻¹ K⁻¹ 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.

中文翻译：

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高维化学空间导航：Ba5Y13[SiO4]8O8.5 和 Ba3Y2[Si2O7]2 的发现


在经过充分研究的BaO-Y ₂ O ₃ -SiO ₂相场中发现了两种化合物。由于合成条件和与玻璃领域的竞争的差异，使用了两种不同的实验程序来探索该系统。通过结合能量色散X射线光谱分析和指导探索的衍射技术分离出第一相Ba ₅ Y ₁₃ [SiO ₄ ] ₈ O _8.5 。使用目标成分的迭代算法识别来定位第二相Ba ₃ Y ₂ [Si ₂ O ₇ ] ₂ 。新化合物的结构解析借助连续旋转电子衍射，并结合同步加速器和中子飞行时间粉末衍射对结构进行细化。 Ba ₅ Y ₁₃ [SiO ₄ ] ₈ O _8.5在I中结晶 2 m ， a = 18.92732(1)， c = 5.357307(6) Å，代表其自身的结构类型，该结构类型结合了嵌入高压相特征的互连钇中心多面体柱中的已知硅酸盐结构的元素。 Ba ₃ Y ₂ [Si ₂ O ₇ ] ₂具有伪四方晶胞的P 2 ₁对称性 ( a = 16.47640(4), b = 9.04150(5), c = 9.04114(7) Å, β = 90.0122(9 )°)，是Ca ₃ BaBi[P ₂ O ₇ ] ₂结构的直接超结构。尽管对称性较低，Ba ₃ Y ₂ [Si ₂ O ₇ ] ₂的结构在Ba/Y位点和二硅酸盐网络中保留了无序性，从而呈现出可能的局部有序片段的叠加。 Ba ₅ Y ₁₃ [SiO ₄ ] ₈ O _8.5在室温下具有1.04(5) W m ^-1 K ^-1的低导热率。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。自动未知相成分识别与多种衍射方法的相互作用，加速了对新结构的高维化学空间的耗时探索。