14:15 〜 14:30
[SIT03-01] Synthesize of boron-doped diamond cylinder as a heater in Multi-anvil apparatus
キーワード：diamond synthesize, B-doped diamond heater, ultrahigh temperature, Multi-anvil apparatus
Diamond is the hardest known material in the world. It is the first time to report synthesize of semi-conductor boron-doped diamond cylinder in the Kawai-type multi-anvil apparatus at 15 GPa and 2100oC. The dimension of the cylinder is 2.6 mm outer diameter, 1.5 mm inner diameter and 3.35 mm length. SEM image shows that the grain size of diamond is about 1 micrometer.
Those cylinders have been used for extremely high temperature generation (~3000oC) in a large sample volume (~0.1mm3) in the Kawai apparatus; the sample volume is ~1000 times larger than that in diamond anvil cell. High X ray transparency of boron-doped diamond is optimum as well for in-situ synchrotron X ray analysis. Although there have been several reports on boron-doped graphite heater, the present study is the first report on pure boron-doped diamond heater in Kawai-type apparatus. The reversibility of the heater was confirmed well through three times of repeated cycle of heating and cooling. The boron-doped diamond heater with 3 wt.% boron shows metallic behavior, i.e. increasing resistance with increasing temperature. This electrical characteristic is beneficial for stably generating temperature as high as 2700oC; the heating for higher temperature was failed because of failure of electrode. Therefore, succeeding optimization is required for higher temperature generation with this new heating element. Boron-doped diamond heater is more advantageous than B-doped graphite heater, because it is free from complicated power-temperature relationship and pressure drop associated with graphite to diamond conversion.
Those cylinders have been used for extremely high temperature generation (~3000oC) in a large sample volume (~0.1mm3) in the Kawai apparatus; the sample volume is ~1000 times larger than that in diamond anvil cell. High X ray transparency of boron-doped diamond is optimum as well for in-situ synchrotron X ray analysis. Although there have been several reports on boron-doped graphite heater, the present study is the first report on pure boron-doped diamond heater in Kawai-type apparatus. The reversibility of the heater was confirmed well through three times of repeated cycle of heating and cooling. The boron-doped diamond heater with 3 wt.% boron shows metallic behavior, i.e. increasing resistance with increasing temperature. This electrical characteristic is beneficial for stably generating temperature as high as 2700oC; the heating for higher temperature was failed because of failure of electrode. Therefore, succeeding optimization is required for higher temperature generation with this new heating element. Boron-doped diamond heater is more advantageous than B-doped graphite heater, because it is free from complicated power-temperature relationship and pressure drop associated with graphite to diamond conversion.