Abstract Oxidation has been suggested as an effective and scalable means for industrial purification of nanodiamond (ND) powders. However, conflicting accounts were reported with respect to oxidation behavior of commercial powders and the temperature range in which non-diamond phases can be removed efficiently. In this study, we investigate the effects of composition and structural characteristics of ND on the oxidation kinetics. The effect of crystal size was analyzed by directly measure the oxidation behavior of individual ND crystal in the size range 2–20 nm, probing the size-dependence of the oxidation kinetics at the lower end of the nanoscale. This study also leads to the first experimental data on the minimum size at which ND crystals become thermodynamically unstable and cease to exist as well as the minimum size of a luminescent ND still hosting an optically active nitrogen-vacancy (NV) center.

中文翻译：

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纳米金刚石粉末的结构和组成对热稳定性和氧化动力学的影响

摘要 氧化被认为是纳米金刚石 (ND) 粉末工业纯化的有效且可扩展的手段。然而，在商业粉末的氧化行为和可以有效去除非金刚石相的温度范围方面，报告了相互矛盾的说法。在这项研究中，我们研究了 ND 的组成和结构特征对氧化动力学的影响。通过直接测量 2-20 nm 尺寸范围内单个 ND 晶体的氧化行为来分析晶体尺寸的影响，探测纳米级下端氧化动力学的尺寸依赖性。