石墨相C_3N_4压致结构相变研究

Study on the Pressure-Induced Phase Transition of g-C_3N_4

将有机物三聚氰胺(C3N6H6)高温热解,得到了石墨相C3N4(g-C3N4)。利用同步辐射X射线衍射和金刚石对顶砧(DAC)高压技术,在室温下对g-C3N4进行了结构变化研究。实验结果表明,在16.57 GPa压力范围内,g-C3N4发生了压致结构相变,在6.6 GPa压力下,晶体结构由原来的石墨相转变为三斜相。使用Birch-Murnagha等温状态方程拟合出了样品的等温状态方程。

Graphitic carbon nitride （g-C3N4） is prepared by pyrolysis of melamine. At room temperature, the structure change of the g-C3N4 is investigdted by in situ high pressure angle-dispersive X-ray diffraction with a synchrotron radiation source,which is in a diamond-anvil cell. The results show that structural phase transition occurred in g C3N4 within 16.57 GPa pressure range. The crystal structure changes from graphitic to trictinic structure at 6.6 GPa. The isothermal equation of the state of C3N4 is fitted using the Birch-Murnagha equation of state.