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, 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 p-T curve is corresponding to the occurrence of to 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 p-T curve for some materials.