论文标题
非弹性中子散射：确定平衡同位素分级因子的新方法。尺寸对钻石的热容量和β因子的影响
Inelastic neutron scattering: A novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond
论文作者
论文摘要
提出了一种基于非弹性中子散射（INS）的物质的平衡同位素特性的新实验方法。我们提出了数学形式主义，允许根据态的状态语音子密度（PDOS）计算单元固体的β因子。通过非弹性中子散射实验确定了广泛不同尺寸和宏观钻石的纳米座的PDOS数据。这允许确定热能力，并首次确定钻石纳米颗粒的\ b {eta} fextor。我们证明，相对于散装钻石，纳米原子座的热容量的大小依赖性增加和β因子的减小。评估了表面杂质/相位和声子限制对大小效应的贡献。简要讨论了自然界中钻石纳米颗粒形成的应用。
A new experimental method of determination of equilibrium isotopic properties of substances based on Inelastic Neutron Scattering (INS) is proposed. We present mathematical formalism allowing calculation of beta-factor of single-element solids based on INS-derived Phonon Density of States (PDOS). PDOS data for nanodiamonds of widely different sizes and of macroscopic diamond were determined from Inelastic Neutron Scattering experiment. This allowed determination of heat capacities and, for the first time, \b{eta}-factors for the diamond nanoparticles. We demonstrate considerable size-dependent increase of the heat capacities and decrease of the beta-factors for nanodiamonds relative to bulk diamond. Contributions of surface impurities/phases and phonon confinement to the size effects are evaluated. Applications to formation of diamond nanoparticles in nature are briefly discussed.
