正辛烷的高压拉曼光谱研究  

Raman Scattering Studies of n-Octane under High Pressure

作　　者：武晓鑫[1] 李敏[2] 李芳菲[2] 周强[2] 高伟[2] 崔启良[2] 邹广田[2] 

机构地区：[1]吉林大学材料科学与工程学院,吉林长春130020 [2]吉林大学超硬材料国家重点实验室,吉林长春130012

出　　处：《高压物理学报》2009年第4期305-309,共5页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(10574054);国家重点基础研究发展计划(2001CB711201;2005CB724400);吉林大学大学生创新性实验计划(2009A43045)

摘　　要：采用金刚石对顶砧高压装置,在室温下对正辛烷(C8H18)进行了原位高压拉曼光谱研究,实验的最高压力为13 GPa。在实验的压力范围内,正辛烷的拉曼峰位随压力的升高均向高频移动,峰强逐渐减弱,峰形变宽。常态为液态的正辛烷在0.8 GPa时,拉曼频移随压力的变化曲线出现了拐点,发生了液-固相变;在6.8 GPa时,伴随着原拉曼峰的消失或劈裂,以及新拉曼峰的出现,此时正辛烷可能发生了固-固相变。该相变压力低于已有的低碳数正烃烷的压致相变结果。正烃烷的压致相变压力点,具有随着结构链长的增加,其相变压力降低的规律。High pressure Raman spectra of n-octane were investigated by diamond anvil cell（DAC） at pressure up to 7 GPa and ambient temperature.The result shows that the liquid-solid phase transition of n-octane takes place around 0.8 GPa.Within the experimental pressure range,the Raman shift of n-octane moves to higher frequency,while the peak intensity decreases,and the width of peaks broaden with increasing pressure.A turning point is observed in the curve of pressure-dependent Raman shift when the pressure increases up to 6.8 GPa.This result indicates that a solid-solid phase transition for n-octane has been finished at this pressure.The pressure-induced phase transition pressure in alkanes decreases with the length of their chains increasing.

关 键 词：正辛烷 RAMAN光谱 高压 相变 金刚石对顶砧 

分 类 号：O521.2[理学—高压高温物理]