发表机构
Masaryk University（马萨里克大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过第一性原理计算确定碳化钛中重构钛空位的C 1s指纹特征，发现重构产生2.34-2.80 eV的大正位移，可为实验探测提供参考能量。
AI 中文摘要
最近的第一性原理搜索预测，岩盐结构TiC中的钛空位并非一个空的八面体位置，而是可以通过碳弗伦克尔对和短C-C键的形成而重构。我们确定了这些局部结构的C 1s特征，并评估了在无序碳存在时这些特征是否仍然具有特异性。采用自洽芯孔方法计算了未重构空位和四种代表性C-C键合重构的位点分辨结合能。未重构空位使其最近邻C 1s能级仅移动-0.36 eV。相比之下，每个重构模型中的最大正位移范围为2.34 eV至2.80 eV。大的位移发生在参与重构C-C网络的碳原子上，并与显著不那么负的Mulliken电荷相关，为空位重构提供了候选的局部指纹。然而，一个探索性的TiC/非晶碳模型表明，无序碳环境可以延伸到相同的高结合能范围。总体而言，计算得到的位移为在TiC中实验搜索重构Ti空位提供了参考能量。
英文摘要
Recent first-principles searches predict that a titanium vacancy in rocksalt TiC is not an empty octahedral site but can reconstruct through the formation of carbon Frenkel pairs and short C-C bonds. We determine the C 1s signatures of these local structures and assess whether they remain specific in the presence of disordered carbon. Site-resolved binding energies were calculated with a self-consistent core-hole method for an unreconstructed vacancy and four representative C-C-bonded reconstructions. The unreconstructed vacancy shifts its nearest-neighbour C 1s level by only -0.36 eV. In contrast, the largest positive shift in each reconstructed model ranges from 2.34 eV to 2.80 eV. The large shifts occur at carbon atoms participating in the reconstructed C-C network and correlate with markedly less negative Mulliken charges, providing candidate local fingerprints of vacancy reconstruction. However, an exploratory TiC/amorphous-C model shows that disordered carbon environments can extend into the same high-binding-energy range. Overall, the calculated shifts provide reference energies for experimental searches for reconstructed Ti vacancies in TiC.
