Phase transformations and vibrational properties of coronene under pressure

Authors：Zhao Xiao Miao^*; Zhang Jiang; Berlie Adam; Qin Zhen Xing; Huang Qiao Wei; Jiang Shan; Zhang Jian Bo; Tang Ling Yun; Liu Jing; Zhang Chao; Zhong Guo Hua; Lin Hai Qing; Chen Xiao Jia

Source：Journal of Chemical Physics, 2013, 139(14): 144308.

DOI：10.1063/1.4824384

Both the vibrational and structural properties of coronene have been investigated upon compression up to 30.5 GPa at room temperature by a combination of Raman scattering and synchrotron x-ray diffraction measurements. The spectroscopic and crystallographic results demonstrate that two pressure-induced structural phase transitions take place at 1.5 GPa and 12.2 GPa where the high-pressure phases are identified as monoclinic and orthorhombic crystal structures with space groups of P2/m and Pmmm, respectively. A kink in the slope of the cell parameters as a function of pressure is associated with the disappearance of several internal Raman modes, which suggests the existence of structural distortions or reorganizations at approximately 6.0 GPa. Above 17.1 GPa, almost no evidence of crystallinity can be observed, indicating a possible transformation of coronene into an amorphous phase.

• Institution
  华南理工大学; 中国科学院; 烟台大学; 中国科学院深圳先进技术研究院