Structural Study of a Self-Assembled Gold Mesocrystal Grain by Coherent X-ray Diffraction Imaging
J. Carnis, F. Kirner, D. Lapkin, S. Sturm, Y. Y. Kim, I. A. Baburin, R. Khubbutdinov, A. Ignatenko, E. Iashina, A. Mistonov, T. Steegemans, Th. Wieck, Th. Gemmi… 展开作者
J. Carnis, F. Kirner, D. Lapkin, S. Sturm, Y. Y. Kim, I. A. Baburin, R. Khubbutdinov, A. Ignatenko, E. Iashina, A. Mistonov, T. Steegemans, Th. Wieck, Th. Gemming, A. Lubk, S. Lazarev, M. Sprung, I. A. Vartanyants, E. V. Sturm
Mesocrystals are nanostructured materials consisting of individual nanocrystals having a preferred crystallographic orientation. On mesoscopic length scales, the properties of mesocrystals are strongly affected by structural heterogeneity. Here, we report the detailed structural characterization of a faceted mesocrystal grain self-assembled from 60 nm sized gold nanocubes. Using coherent X-ray diffraction imaging, we determined the structure of the mesocrystal with the resolution sufficient to resolve each gold nanoparticle. The reconstructed electron density of the gold mesocrystal reveals its intrinsic structural heterogeneity, including local deviations of lattice parameters, and the presence of internal defects. The strain distribution shows that the average superlattice obtained by angular X-ray cross-correlation analysis and the real, multidomain structure of a mesocrystal are very close to each other, with a deviation less than 10 percent. These results will provide an important impact to understanding of the fundamental principles of structuring and self-assembly including ensuing properties of mesocrystals.
Molecular stochastic process on gold surface observed in broadband-infrared, background-suppressed, sum frequency generation spectroscopy: picosecond heat transfer to self-assembled monolayers
A Density Functional Theory Investigation of Carboranethiol Self-Assembled Monolayer on Au(111)
用标准密度泛函理论和范德华密度泛函理论研究了碳硼烷乙撑（C $_2$ B $_{10}$ H $_{12}$ S）异构体在金（111）表面的单分子层吸附.研究了不同分子偶极矩取向对这些异构体的低能吸附层几何构型、结合特性和自组装单分子膜的电子性质的影响。具体而言，与不同分子相关的结合能和功函数的变化与它们的偶极矩相关。吸附有利于偶极矩平行于表面的异构体。在两种可能的晶胞结构中，发现（5 $\times$ 5）比（$\sqrt{19}\times\sqrt{19}$）R23.4 $^o$更稳定。
