高温高压后叶蜡石相变的研究

通过三个不同层面对合成金刚石晶体的叶蜡石组装块进行X射线衍射与Raman光谱的检测分析,清晰地表明了叶蜡石晶体在高温高压条件下逐渐相变成硬水铝石、柯石英、蓝晶石的过程.进而得出选择适当的白云石套管壁厚,阻止过多,高硬度蓝晶石新相的形成,以构成合成腔体内压力、温度的合理匹配对合成高质量金刚石有着重要的指导意义.

Research of phase transition of pyrophyllite after high temperature and high pressure

The pyrophyllite assembly used in synthesis of diamond crystal was analyzed by X-ray diffraction and Raman spectrum examination. The results indicated that the pyrophyllite crystals were gradually deeomposed into hard diaspore, quartz and kyanite under high temperature and high pressure. It is eoneluded that a suitable thickness of dolomite drive pipe wall would prevent the formation of excessively high hardness kyanite, which make more even distribution of pressure and temperature in the high pressure assembly. The results are very important to the synthesis of high quality diamonds.