無機塩類を触媒とするダイヤモンドの合成
1992 年 1 巻 1 号 p. 52-59
詳細
1992 年 1 巻 1 号 p. 52-59
Since the first success in diamond synthesis by using transition metals such as Fe, Co, Ni and their alloys as diamond-producing catalysts under very high temperatures and pressures, inorganic compounds such as carbonates have also been expected as the catalysts. The authors have recently found that diamond can be synthesized from graphite in the presence of the carbonates, sulfates and hydroxides of alkali and alkaline earth metals at about 7. 7 GPa and 2000°C. So far, by using these new catalysts, various kinds of diamond grains could be obtained. Besides, crystal growth of diamond could be realized on the faces of seed diamond crystals at lower pressures and temperatures of about 5. 5 GPa and 1600-1800°C. Diamond powder could be sintered by using alkaline earth carbonates as a sintering aid at 7. 7 GPa and 2000-2450°C.
