【摘要】 为了研究石墨Ni₇₀Mn₂₅Co₅体系在高压高温下石墨的变化和金刚石的生长现象,用六面顶压机对交替组装的圆片状石墨和Ni₇₀Mn₂₅Co₅触媒进行高温高压处理及金刚石合成实验。扫描电镜观察结果表明:在触媒中再结晶石墨以片状为主,而类球状石墨由片状石墨的堆积长大形成的;覆盖在金刚石的金属包膜中有大约1μm厚的片状石墨。借助于多功能光学显微镜,观察到金刚石的晶体形态和缺陷特征随合成温度、压力的不同有规律地变化。实验证实了高温高压下石墨Ni₇₀Mn₂₅Co₅体系中石墨和金刚石的层状生长现象,进而提出了预防金刚石宏观缺陷、合成优质金刚石的技术措施。更多还原

【Abstract】 In order to investigate the phenomena of graphite variation and diamond growth in a graphiteNi 70 Mn 25 Co₅ alloy system, experiments for the treatment of alternatively stacked discs of graphiteNi 70 Mn 25 Co₅ alloy and the synthesis of diamond crystals were carried out using a cubic anvil cell press under high pressure and high temperature. The results observed by scanning electron microscopy indicate that the recrystallized graphite in Ni 70 Mn 25 Co₅ alloy mainly has a flaky shape, while some sphere-like graphite is formed by the packing of flaky graphite. Additionally, flaky graphite with a thickness of about 1 μm was also observed in the metallic film wrapping the diamond. Typical morphologies and defects of diamond crystals, which vary regularly with the changes of pressure and temperature, were also analyzed by means of a multi-function microscope. The laminar growth phenomena of graphite and diamond were verified in the experiment of the graphiteNi 70 Mn 25 Co₅ system under high pressure and high temperature. Moreover, a key synthetic technique is suggested to prevent the macro-defects produced during the diamond growth, and thus a high-quality diamond can be synthesized.更多还原