Thermobarometric calculations for mineral diamond inclusions and associations(DIA)provide a systematic comparison of PTXFO2 conditions for different cratons worldwide,using a database of 4440 mineral EPMA analyses(Ash...Thermobarometric calculations for mineral diamond inclusions and associations(DIA)provide a systematic comparison of PTXFO2 conditions for different cratons worldwide,using a database of 4440 mineral EPMA analyses(Ashchepkov et al.,2021).展开更多
Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) ...Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) technology of X-ray powder diffraction was applied to the study of the inclusion in diamond from the ophiolite of Tibet. Diffraction patterns are obtained even though the inclusion is only 20 μm in crystal size. The results show that the inclusion in diamond consists of talc and clinochrysotile. Therefore, it is clear that the diamond from the ophiolite of Luobusha, Tibet, is natural diamond rather than a synthetic one.展开更多
Large diamonds have successfully been synthesized from FeNiMnCo-S-C system at temperatures of 1255-1393 ℃and pressures of 5.3-5.5 GPa.Because of the presence of sulfur additive,the morphology and color of the large d...Large diamonds have successfully been synthesized from FeNiMnCo-S-C system at temperatures of 1255-1393 ℃and pressures of 5.3-5.5 GPa.Because of the presence of sulfur additive,the morphology and color of the large diamond crystals change obviously.The content and shape of inclusions change with increasing sulfur additive.It is found that the pressure and temperature conditions required for the synthesis decrease to some extent with the increase of S additive,which results in left down of the V-shape region.The Raman spectra show that the introduction of additive sulfur reduces the quality of the large diamond crystals.The x-ray photoelectron spectroscopy(XPS) spectra show the presence of S in the diamonds.Furthermore,the electrical properties of the large diamond crystals are tested by a four-point probe and the Hall effect method.When sulfur in the cell of diamond is up to 4.0 wt.%,the resistance of the diamond is 9.628×105 Ω·cm.It is shown that the large single crystal samples are n type semiconductors.This work is helpful for the further research and application of sulfur-doped semiconductor large diamond.展开更多
基金supported by the RFBR grant 19-05-00788supported by the Ministry of Science and Higher Education of the Russian Federation
文摘Thermobarometric calculations for mineral diamond inclusions and associations(DIA)provide a systematic comparison of PTXFO2 conditions for different cratons worldwide,using a database of 4440 mineral EPMA analyses(Ashchepkov et al.,2021).
基金supported by the National Natural Science Foundation of China grants 4997203 and 49872019.
文摘Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) technology of X-ray powder diffraction was applied to the study of the inclusion in diamond from the ophiolite of Tibet. Diffraction patterns are obtained even though the inclusion is only 20 μm in crystal size. The results show that the inclusion in diamond consists of talc and clinochrysotile. Therefore, it is clear that the diamond from the ophiolite of Luobusha, Tibet, is natural diamond rather than a synthetic one.
基金Project supported by the National Natural Science Foundation of China(Grant No.51172089)the Education Department of Henan Province,China(Grant No.12A430010)the Fundamental Research Funds for the Universities of Henan Province,China(Grant No.NSFRF140110)
文摘Large diamonds have successfully been synthesized from FeNiMnCo-S-C system at temperatures of 1255-1393 ℃and pressures of 5.3-5.5 GPa.Because of the presence of sulfur additive,the morphology and color of the large diamond crystals change obviously.The content and shape of inclusions change with increasing sulfur additive.It is found that the pressure and temperature conditions required for the synthesis decrease to some extent with the increase of S additive,which results in left down of the V-shape region.The Raman spectra show that the introduction of additive sulfur reduces the quality of the large diamond crystals.The x-ray photoelectron spectroscopy(XPS) spectra show the presence of S in the diamonds.Furthermore,the electrical properties of the large diamond crystals are tested by a four-point probe and the Hall effect method.When sulfur in the cell of diamond is up to 4.0 wt.%,the resistance of the diamond is 9.628×105 Ω·cm.It is shown that the large single crystal samples are n type semiconductors.This work is helpful for the further research and application of sulfur-doped semiconductor large diamond.