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Novel configurations of VN4 and VN4H defects in diamond platelets: Structure, energetics and vibrational properties
Diamond and Related Materials ( IF 4.1 ) Pub Date : 2020-10-01 , DOI: 10.1016/j.diamond.2020.107957
Tingting Gu , Sebastian Ritterbex , Taku Tsuchiya , Wuyi Wang

Abstract Atomic structure and lattice dynamics properties of the novel configurations of VN4 and VN4H defects in combination with the {001} platelet structure in diamond are investigated by first-principles density functional techniques. We find that incorporation of B centers (VN4) in the platelet structure substantially reduce the formation energy of B centers by ~0.45 eV for both structure models, suggesting that they may tend to develop preferentially together with platelets. Moreover, our results provide evidence that VN4 centers in the platelet might be effective sinks for atomic hydrogen in diamond. Vibrational properties of the defective structures are computed by using the linear response density functional perturbation theory (DFPT). N H stretching modes for VN4H centers appear around 3221 (model 1) and 3095 (model 2) cm−1, suggesting that the experimental vibrational modes of 3085.4, 3107 and 3237 cm−1 observed in natural IaA/B diamonds could be attributed to the VN4H defects. Moreover, we observed that incorporation of VN4H centers quenches the platelet IR absorption, which is unconventional but important in understanding the platelet degradation phenomenon. Our calculations shed light on possible novel configurations of VN4H centers and platelets, which can be extrapolated to VN4H2 centers as well as to a more hybrid platelet structure, and elucidate the role of nitrogen and hydrogen in the development of platelet defects in diamond.

中文翻译:

金刚石片晶中 VN4 和 VN4H 缺陷的新构型:结构、能量学和振动特性

摘要 通过第一性原理密度泛函技术研究了与金刚石中的 {001} 片晶结构相结合的 VN4 和 VN4H 缺陷的新构型的原子结构和晶格动力学特性。我们发现,对于两种结构模型,在血小板结构中掺入 B 中心(VN4)大大降低了 B 中心的形成能约 0.45 eV,表明它们可能倾向于优先与血小板一起发育。此外,我们的结果提供证据表明,片晶中的 VN4 中心可能是钻石中原子氢的有效汇。缺陷结构的振动特性是通过使用线性响应密度泛函微扰理论 (DFPT) 来计算的。VN4H 中心的 NH 拉伸模式出现在 3221(模型 1)和 3095(模型 2)cm−1 附近,表明在天然 IaA/B 钻石中观察到的 3085.4、3107 和 3237 cm-1 的实验振动模式可归因于 VN4H 缺陷。此外,我们观察到 VN4H 中心的加入抑制了血小板 IR 吸收,这是非常规的,但对于理解血小板降解现象很重要。我们的计算揭示了 VN4H 中心和片晶的可能新构型,这些构型可以外推到 VN4H2 中心以及更混合的片晶结构,并阐明氮和氢在金刚石片晶缺陷形成中的作用。我们观察到 VN4H 中心的加入抑制了血小板的 IR 吸收,这是非常规的,但对于理解血小板降解现象很重要。我们的计算揭示了 VN4H 中心和片晶的可能新构型,这些构型可以外推到 VN4H2 中心以及更混合的片晶结构,并阐明氮和氢在金刚石片晶缺陷形成中的作用。我们观察到 VN4H 中心的加入抑制了血小板的 IR 吸收,这是非常规的,但对于理解血小板降解现象很重要。我们的计算揭示了 VN4H 中心和片晶的可能新构型,这些构型可以外推到 VN4H2 中心以及更混合的片晶结构,并阐明氮和氢在金刚石片晶缺陷形成中的作用。
更新日期:2020-10-01
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