Experimental Study of Diamond Formation in Astrophysical Environments

天体物理环境中钻石形成的实验研究

• 批准号: 281937660
• 负责人: Dr. Cornelia Jäger
• 金额: --
• 依托单位: Max-Planck-Institut für Astronomie (MPIA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/281937660?language=en
• 关键词: Experimental; Study; Diamond; Formation; Astrophysical

Diamond represents a major part of the carbonaceous cosmic dust. However the formation route of cosmic diamond is not well understood. The present project is devoted to the study of diamond formation at conditions which are similar to those found in the interstellar medium and stellar envelops including evolved stars, protoplanetary, and planetary environments. The project consists of two strongly related tranches. In the first part, we will study the erosion of carbon material in hydrogen-rich, cosmic environments. We will study the etching of graphite, amorphous carbon, and diamond material by atomic and molecular hydrogen at temperatures ranging from 10 K to 1400 K. These temperatures represent the formation conditions in various astrophysical environments. In low-temperature conditions, UV irradiation will be used to facilitate the erosion. These data will provide important information on the chemical stability of carbonaceous and diamond grains in the different astrophysical regions. In the second part of the project, the obtained erosion data will be applied for the finding of appropriate astrophysical condensation conditions of diamond. Atomic hydrogen and carbon, which belong to the most abundant species in our Universe, will be used for the study of the chemical vapor deposition process of diamond. The deposition conditions of diamond will mimic astrophysical conditions. The atomic carbon and hydrogen flows will be simultaneously directed and deposited onto an appropriate substrate such as silicon wafer or diamond seeded crystals. We will use a newly developed atomic carbon source, which provides an intense and pure flux of low-energy atomic carbon. The diamond growth will be monitored in situ by Raman spectroscopy. Further characterization of the deposit will be performed using infrared, ultraviolet, and visible absorption spectroscopy, and high-resolution transmission electron microscopy. The evaluation of the experimental results with regard to astrophysical formation conditions enables us to predict the astrophysically relevant sites of efficient diamond formation and the formation pathways.

钻石代表碳质宇宙尘埃的主要部分。然而宇宙钻石的形成路线尚不清楚。本项目致力于研究在类似于星际介质和恒星包层（包括演化恒星、原行星和行星环境）中发现的条件下钻石的形成。该项目由两个密切相关的部分组成。在第一部分中，我们将研究碳材料在富氢的宇宙环境中的侵蚀。我们将研究原子和分子氢在 10 K 至 1400 K 的温度下对石墨、无定形碳和金刚石材料的蚀刻。这些温度代表了各种天体物理环境中的形成条件。在低温条件下，将采用紫外线照射以促进侵蚀。这些数据将提供有关不同天体物理区域碳质和金刚石颗粒化学稳定性的重要信息。在该项目的第二部分中，获得的侵蚀数据将用于寻找合适的钻石天体物理凝结条件。原子氢和碳属于宇宙中最丰富的物种，将用于研究金刚石的化学气相沉积过程。金刚石的沉积条件将模拟天体物理条件。原子碳流和氢流将同时被引导并沉积到适当的基底上，例如硅晶片或金刚石籽晶。我们将使用新开发的原子碳源，它提供强烈而纯净的低能原子碳通量。钻石的生长将通过拉曼光谱进行原位监测。将使用红外、紫外和可见吸收光谱以及高分辨率透射电子显微镜对沉积物进行进一步表征。对天体物理形成条件实验结果的评估使我们能够预测有效钻石形成的天体物理相关位点和形成路径。

项目成果

Low-temperature Condensation of Carbon

碳的低温凝结

• DOI: 10.3847/1538-4357/aa88a4
• 发表时间: 2017
• 期刊: The Astrophysical Journal
• 作者: S. A. Krasnokutski;M. Goulart;E. B. Gordon;A. Ritsch;C. Jäger;M. Rastogi;W. Salvenmoser;Th. Henning;P. Scheier
• 通讯作者: P. Scheier