Abstract We report polarization dependent, scanning transmission X-ray microscopy measurements of individual boron nitride nanotubes (BNNTs) and analyze them by means of first-principles calculations. X-ray absorption near-edge spectra of hexagonal boron-nitride (hBN) are calculated as a function of light polarization and layer stacking and best agreement with recent experimental data is obtained for the commonly assumed AA' stacking. Our experimental BNNT spectra show a pronounced polarization dependence which is qualitatively well reproduced in the calculations. We show that the BNNT has a mixed stacking sequence which may explain some of the differences seen between the hBN and BNNT line shapes.

中文翻译：

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氮化硼纳米管的偏振相关 X 射线吸收近边光谱

摘要 我们报告了单个氮化硼纳米管 (BNNT) 的偏振相关扫描透射 X 射线显微镜测量，并通过第一性原理计算对其进行了分析。六方氮化硼 (hBN) 的 X 射线吸收近边光谱被计算为光偏振和层堆叠的函数，并且对于通常假设的 AA' 堆叠获得了与最近实验数据的最佳一致性。我们的实验 BNNT 光谱显示出明显的偏振依赖性，这在计算中得到了很好的再现。我们表明 BNNT 具有混合堆叠序列，这可以解释 hBN 和 BNNT 线形之间的一些差异。