The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "F...The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "FeNi+Ti", "FeNi+G_(3)N_(6)H_(6)",and "FeNi+Ti+C_(3)N_(6)H_(6)".Optical microscopy,infrared spectroscopy,and photoluminescence(PL)spectroscopy measurements were conducted to analyze the spectroscopic characteristics of diamonds grown in these three systems.From our analysis,it was demonstrated that the presence of hydrogen in the sp^(3) hybrid C-H does not directly affect the color of the diamond and facilitates the increase of the nitrogen-vacancy(NV) center concentration in a highnitrogen-content diamond.In addition,titanium plays an important role in nitrogen removal,while its impact on hydrogen doping within the diamond lattice is insignificant.Most importantly,by regulating the ratio of nitrogen impurities that coexist in the nitrogen and hydrogen HPHT environment,the production of hydrogenous Ⅱa-type diamond,hydrogenous Ib-type diamond,and hydrogenous high-nitrogen-type diamonds was achieved with a nitrogen content of less than 1 ppm to 1600 ppm.展开更多
By temperature gradient method under high pressure and high temperature (HPHT), with NiMnCo alloy as the solvent metal, at diamond-stable region of about 5.4 GPa and 1500 K, metastable regrown graphite crystals of d...By temperature gradient method under high pressure and high temperature (HPHT), with NiMnCo alloy as the solvent metal, at diamond-stable region of about 5.4 GPa and 1500 K, metastable regrown graphite crystals of different morphology were synthesized. With B as an additive incorporated into the NiMnCo-C system, metastable regrown graphite crystals of sphere-like shape were firstly obtained under HPHT. If the growth system does not contain B, sheet-like regrown graphite crystals, most with regular hexagonal morphology, are grown upwards and standing vertically in the metal solvent. When B additive of 1.0 wt pct was added into carbon source (graphite powder), all metastable regrown graphite crystals took on the habit of regular sphere-like morphology, and were grown by a spiral layer growth mechanism.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 12274373 and 12004341)the Open Project of Inner Mongolia Key Laboratory of High-pressure Phase Functional Materials,Chifeng University (Grant No. cfxygy202301)+1 种基金the Science and Technology Project of Xilinguole Province (Grant No. 202209)the Natural Science Foundation of Henan Province (Grant No. 242300421155)。
文摘The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "FeNi+Ti", "FeNi+G_(3)N_(6)H_(6)",and "FeNi+Ti+C_(3)N_(6)H_(6)".Optical microscopy,infrared spectroscopy,and photoluminescence(PL)spectroscopy measurements were conducted to analyze the spectroscopic characteristics of diamonds grown in these three systems.From our analysis,it was demonstrated that the presence of hydrogen in the sp^(3) hybrid C-H does not directly affect the color of the diamond and facilitates the increase of the nitrogen-vacancy(NV) center concentration in a highnitrogen-content diamond.In addition,titanium plays an important role in nitrogen removal,while its impact on hydrogen doping within the diamond lattice is insignificant.Most importantly,by regulating the ratio of nitrogen impurities that coexist in the nitrogen and hydrogen HPHT environment,the production of hydrogenous Ⅱa-type diamond,hydrogenous Ib-type diamond,and hydrogenous high-nitrogen-type diamonds was achieved with a nitrogen content of less than 1 ppm to 1600 ppm.
基金supported by the National Natural Science Foundation of China under grant No.50172018the Foundation of He nan Educational Committee undergrant No.2009A430014the Open Research Fund Program of State Key Laboratory of Superhard Materials of Jilin University under grant No.200801
文摘By temperature gradient method under high pressure and high temperature (HPHT), with NiMnCo alloy as the solvent metal, at diamond-stable region of about 5.4 GPa and 1500 K, metastable regrown graphite crystals of different morphology were synthesized. With B as an additive incorporated into the NiMnCo-C system, metastable regrown graphite crystals of sphere-like shape were firstly obtained under HPHT. If the growth system does not contain B, sheet-like regrown graphite crystals, most with regular hexagonal morphology, are grown upwards and standing vertically in the metal solvent. When B additive of 1.0 wt pct was added into carbon source (graphite powder), all metastable regrown graphite crystals took on the habit of regular sphere-like morphology, and were grown by a spiral layer growth mechanism.