Abstract Diamond micro powders have been synthesized by chemical vapor deposition via etching a graphite substrate in hydrogen microwave plasma, without a hydrocarbon (methane) gas addition. The graphite temperature, varying from 700 to 1000 °C, was found to significantly affect the diamond nucleation and growth, the growth rate of the diamond particles increasing from 2.4 to ≈ 4 μm/h with the temperature. The diamond powders had a better crystalline quality at the substrate temperature of 900 °C. Because of low adhesion of the deposited grit to the substrate the particles can be collected easily and mechanically disaggregated. The average size of ≈ 12 μm of the dispersed particles grown for 5 h, was determined with a laser particle size analyzer, while the maximum grain size estimated with electron microscopy, varied between 12 and ≈ 20 μm. The particle's surface exhibited many micro-pyramids with sharp tips, that could be beneficial for abrasive applications. X-ray diffraction and Raman spectroscopy revealed high purity and quality of the diamond powders.

中文翻译：

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在微波氢等离子体中通过石墨蚀刻合成金刚石微粉

摘要 金刚石微粉是通过化学气相沉积法通过在氢微波等离子体中蚀刻石墨基底合成的，无需添加碳氢化合物（甲烷）气体。发现石墨温度从 700 到 1000 °C 不等，显着影响金刚石的成核和生长，金刚石颗粒的生长速率随温度从 2.4 增加到 ≈ 4 μm/h。金刚石粉末在 900 °C 的衬底温度下具有更好的结晶质量。由于沉积的砂粒对基材的附着力低，因此可以很容易地收集颗粒并进行机械分解。用激光粒度分析仪测定了 ≈ 12 μm 分散颗粒生长 5 小时的平均尺寸，而用电子显微镜估计的最大晶粒尺寸在 12 和 ≈ 20 μm 之间变化。该颗粒的表面呈现出许多带有尖锐尖端的微金字塔，这可能有利于研磨应用。X 射线衍射和拉曼光谱表明金刚石粉末具有高纯度和质量。