A new boron nitride and graphite composite heater for rapid resistive heating in the diamond anvil cell and dynamic...

We have developed a new ceramic-graphite composite heater for use in the diamond anvil cell. These new heaters have shown the capability to rapidly heat samples at average rates as high as 30 K/s and have been tested up to a maximum sample temperature of 1100 K. We present four scientific case studies in which we test the functionality of the heaters and verify the accuracy of the thermocouple readings by benchmarking to calibrated material responses and to known phase transitions in select materials. The first case study employs time resolved fluorescence measurements of Sm:YAG and ruby, using the Sm:YAG fluorescence to extract the pressure of the cell to determine the temperature based on the ruby measurement. The second case study is a time resolved Raman study of sulfur at high pressure and temperature where we reproduce the known solid-liquid and liquid-liquid transitions. Additionally, in this portion of the study, we also verify the high temperature transition to a trigonal crystal structure. In the third case study, we performed stepwise heating of Sn up to 1100 K and accessed the liquid phase at two different pressures. For the fourth and final case study, we performed time resolved optical microscopy measurements on H2O with the goal of dynamically compressing from liquid H2O into ice-VII at high temperature.