Graphite–boron composite heater in a Kawai-type apparatus - the inhibitory effect of boron oxide and countermeasures
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2016-03-22 |
| Journal | High Pressure Research |
| Authors | Longjian Xie, Akira Yoneda, Takashi Yoshino, Hongzhan Fei, Eiji Ito |
| Institutions | Okayama University |
| Citations | 18 |
Abstract
Section titled “Abstract”We have investigated the performance of a graphite-boron composite (GBC) with 3 wt % boron as a precursor for a boron-doped diamond heater in a Kawai-type apparatus at 15 GPa. We first tested a machinable cylinder of GBC sintered at 1000°C in Ar/H2 gas (99:1 molar ratio). Boron oxide (B2O3) formed during sintering frequently hindered the GBC heater from stable operation at temperatures higher than 1400°C by producing melt throughout the heater together with oxide and/or silicates. We then rinsed the GBC heater in hydrochloric acid to remove B2O3. After rinsing, we succeeded in stably generating temperatures higher than 2000°C. We also improved a molding process of different-sized GBC tubes for convenient use and tested the molded GBC heater. It was free from the B2O3 problem. The electromotive force of the W/Re thermocouple was successfully monitored up to 2400°C.