Nitriding synthesis and structural change of phosphorus nitrides at high pressures
Nitriding synthesis and structural change of phosphorus nitrides at high pressures
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DOI：
10.1002/jrs.6079
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发表时间：
2021-02
影响因子：
2.5
通讯作者：
K. Niwa;Yasunori Iijima;M. Ukita;Ryuta Toda;K. Toyoura;Takuya Sasaki;K. Matsunaga;N. A. Gaida;M. Hasegawa
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文献类型：
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作者：
K. Niwa;Yasunori Iijima;M. Ukita;Ryuta Toda;K. Toyoura;Takuya Sasaki;K. Matsunaga;N. A. Gaida;M. Hasegawa
通过高压原位拉曼光谱、X 射线衍射测量和高达约 80 GPa 的第一原理计算，研究了 γ-P3N5 的相稳定性以及新磷氮化物的可能形成。在这项研究中，γ-P3N5是通过黑磷在大约12 GPa以上的压力下直接氮化合成的。首次通过实验测量了拉曼光谱、体积模量（K0= 130.27(43) GPa）和压缩行为（轴向压缩率的顺序：βc>βa>βb）。这些实验结果与第一性原理计算的结果非常吻合。我们的高压原位测量和第一性原理计算表明，γ-P3N5 在室温下可维持高达 80 GPa。 γ-P3N5 的压缩随着由共享角和边的 PN4 和 PN5 组成的层的折叠而进行。目前的研究结果表明，对于氮化磷来说，低配位数（PN4和PN5）的P-N键在很宽的压力范围内是优选的并且稳定的。然而，在氮气存在的情况下，在 67 至 70 GPa 之间进行激光加热会导致形成新的 PxNy，其中可能会出现新的高压 P3N5 相。拉曼散射测量以及减压表明新合成的 PxNy 的局部结构在大气压下保持稳定。目前对氮化磷的实验和理论研究为由高度配位多面体组成的共价化合物的高压行为提供了新的见解。
The phase stability of γ‐P3N5and the possible formation of new phosphorus nitrides were investigated via high‐pressure in situ Raman spectroscopy, X‐ray diffraction measurements, and first‐principles calculations up to approximately 80 GPa. In this study, γ‐P3N5was synthesized via the direct nitridation of black phosphorus at a pressure approximately above 12 GPa. The Raman spectrum, bulk modulus (K0= 130.27(43) GPa), and compression behaviors (order of axial compressibility:βc>βa>βb) were experimentally measured for the first time. These experimental results were in good agreement with those of first‐principles calculations. Our high‐pressure in situ measurements and first‐principles calculations revealed that γ‐P3N5persisted up to 80 GPa at room temperature. The compression of γ‐P3N5proceeded with the folding of the layer consisting of the corner‐ and edge‐sharing PN4and PN5. The present findings indicate that the P–N bonding with a low coordination number (PN4and PN5) is preferable and stabilized for phosphorus nitride over a wide pressure range. However, laser heating between 67 and 70 GPa in the presence of nitrogen resulted in the formation of new PxNy, which included the possibility of a new high‐pressure P3N5phase. The Raman scattering measurements along with the decompression demonstrated that the local structure of the newly synthesized PxNymetastably persisted at atmospheric pressure. The present experimental and theoretical studies on phosphorus nitrides offer new insights into the high‐pressure behaviors of covalent compounds consisting of highly coordinated polyhedra.