外加热型金刚石对顶压砧高压装置及高温下的压力测量

 本文报导了一种外加热型金刚石对顶压砧装置的高温高压技术，装置的压力可达20 GPa，温度可达350 ℃。采用本装置对六角结构的α-LiIO₃进行了高温高压X射线衍射实验，获得的四方结构高压相与用淬火卸压所得的ε相结构一致；建立了高温下的红宝石测试技术。发现可以根据由此法测定的Δγ_p-T曲线初步判别样品是否存在伴随有体积变化的结构相变，并可估计出该相变的压力、温度范围及相变造成的压力下降值。

A DIAMOND ANVIL CELL WITH EXTERNAL HEATER AND PRESSURE MEASUREMENT BY USING RUBY AT HIGH TEMPERATURE

The techniques of diamond anvil cell used in our laboratory with external heater under high pressure and high temperature are described in this paper. The pressure and the temperature can be up to 20 GPa and 350 ℃, respectively. The high pressure phase of LiIO₃, ε phase has been determined in situ by using X-ray diffraction analysis in this device. The pressure measurement with ruby at high temperature in this device is discussed. According to the LiIO₃ data of X-ray diffraction analysis, it is shown that the dropping part of Δγ_p-T curve is corresponding to the occurrence of α to ε phase transition of LiIO₃ under high pressure and high temperature. We suppose that one can estimate the phase transition temperature and pressure as well as the decreasing value of pressure caused by phase transition from Δγ_p-T curve for some materials.