High-Pressure Synthesis of Novel Boron Oxynitride B6N4O3 with Sphalerite Type Structure
High-Pressure Synthesis of Novel Boron Oxynitride B6N4O3 with Sphalerite Type Structure
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DOI：
10.1021/acs.chemmater.5b01706
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发表时间：
2015-09-08
影响因子：
8.6
通讯作者：
Riedel, Ralf
中科院分区：
文献类型：
--
作者：
Bhat, Shrikant;Wiehl, Leonore;Riedel, Ralf
在超过15 GPa的静压和1900 ℃以上的温度下，由B2 O3和h-BN的摩尔混合物合成了一种新型的结晶氮氧化硼（BON）相。合成产物的结构和组成进行了研究，使用高分辨率透射电子显微镜，电子衍射，自动衍射断层扫描，能量色散X射线光谱和电子能量损失谱（EELS）。BON具有六方晶胞（R3 m，Z = 3），晶格参数a = 2.55（5）A和c = 6.37（13）A，晶体结构与立方闪锌矿型密切相关。EELS定量产生42 at % B、35 at % N和23 at % 0（B：N：O近似于6：4：3）。在密度泛函理论的框架内的电子结构计算已经进行了评估的稳定性和所选模型的组成B6 N4 O3的属性。这些模型含有有序的结构空位，是闪锌矿结构的超结构。计算出的体积模量的结构模型与最低的形成magnesipies是约300 GPa，高于任何其他已知的氮氧化物。
A novel crystalline boron oxynitride (BON) phase has been synthesized under static pressures exceeding 15 GPa and temperatures above 1900 degrees C, from molar mixtures of B2O3 and h-BN. The structure and composition of the synthesized product were studied using high-resolution transmission electron microscopy, electron diffraction, automated diffraction tomography, energy dispersive X-ray spectroscopy and electron energy-loss spectroscopy (EELS). BON shows a hexagonal cell (R3m, Z = 3) with lattice parameters a = 2.55(5) A and c = 6.37(13) angstrom, and a crystal structure closely related to the cubic sphalerite type. The EELS quantification yielded 42 at % B, 35 at % N, and 23 at % 0 (B:N:O approximate to 6:4:3). Electronic structure calculations in the framework of Density Functional Theory have been performed to assess the stabilities and properties of selected models with the composition B6N4O3. These models contain ordered structural vacancies and are superstructures of the sphalerite structure. The calculated bulk moduli of the structure models with the lowest formation enthalpies are around 300 GPa, higher than for any other known oxynitride.