Time-resolved Raman spectroscopy of metastable phase transformations in silicates under high-pressures and -temperatures

本文研制了一套用于金刚石压砧中红宝石荧光法测量压力的激光拉曼光谱仪系统，该系统是一台高空间分辨率的显微拉曼光谱仪。尽管需要进一步改进以降低由杂散光引起的高背景水平，但拉曼系统能够1）评估钾长石和钠斜长石中的压力诱导非晶化，2）测定水镁石在高压和高温下的H-D互扩散系数，3）致密含水镁硅酸盐的物相鉴定和氢同位素均匀性评价中子衍射研究

In the present study, a laser spectrometer system for pressure determination in a diamond anvil cell by the ruby fluorescence method was developed to be a micro-Raman spectrometer with high-spatial resolution. Although further improvement to reduce high background level caused by stray lights is required, the Raman system enabled 1) evaluation of pressure-induced amorphization in K-feldspar and Na-plagioclase, 2) determination of H-D interdiffusion coefficients in brucite under high pressures and temperatures, and 3) phase identification and evaluation of homogeneity of hydrogen isotopes in dense hydrous magnesium silicates for pulsed-neutron diffraction studies.