PI薄膜在炭化和石墨化过程中表面结构的喇曼散射研究

RAMAN SPECTROSCOPIC STUDY ON THE SURFACE STRUCTURE OF POLYIMIDE THIN FILM DURING CARBONIZATION AND GRAPHITIZATION

研究了ＰＩ（聚酰亚胺）薄膜在不同的炭化和石墨化温度条件下进行热处理所获得的激光喇曼光谱的特征及其结构变化的规律。结果表明，随着热处理温度的升高，试样中归属于Ａ１ｇ和Ｅ２ｇ模式的１３５８ｃｍ－１峰和１５７８ｃｍ－１散射峰的伸缩振动依赖于杂环稠合苯环所构成的分子结构。在２１００℃以前，碳体的分子结构发生明显变化，有序性增加，无序区减小。当温度达到２８００℃时，该试样便转变为属于Ｄ６ｈ空间群的六角平面的层状石墨结构。另外，还估算了试样在１０００℃至１７００℃温度范围内碳体微晶尺寸（Ｌａ）的值，发现在此温间Ｌａ成长较慢。

The laser Raman spectroscopic characterization and structural change of polyimide thin film at various carbonization and graphitization temperature were studied. The results show that with rising heatment temperature the stretching vibration of 1358 cm-1 and 1587 cm-1 scattering peaks of assigning to the vibrational modes of A1g and E2g types is dependent on the constructive molecular structure of the heterocyclic condensed benzene ring in sample. Before 2100 ℃ the change of the molecular structure of carbon body occurred markelly, the order increases and the disorder zone decreases. When the temperature reach to 2800 ℃ the sample transformation into sixangular plane layer graphite structure of D6h space group attributed. In addition the value of carbon microcrystalline size (La) for sample have been estimated in a temperature range between 1000 ℃ and 1700 ℃. It is found that the La value was grew gradually.