Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany.
National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, 115409, Moscow, Russia.
Small. 2019 Dec;15(50):e1904954. doi: 10.1002/smll.201904954. Epub 2019 Nov 14.
X-ray nanodiffraction is applied to study the formation and correlation of domain boundaries in mesocrystalline superlattices of PbS nanocrystals with face-centered cubic structure. Each domain of the superlattice can be described with one of two mesocrystalline polymorphs with different orientational orders. Close to a grain boundary, the lattice constant decreases and the superlattice undergoes an out-of-plane rotation, while the orientation of the nanocrystals with respect to the superlattice remains unchanged. These findings are explained with the release of stress on the expense of specific nanocrystal-substrate interactions. The fact that correlations between adjacent nanocrystals are found to survive the structural changes at most grain boundaries implies that the key to nanocrystal superlattices with macroscopic domain sizes are strengthened interactions with the substrate.
X 射线纳米衍射被应用于研究具有面心立方结构的 PbS 纳米晶的介晶超晶格中畴界的形成和关联。超晶格的每个畴都可以用两种具有不同取向序的介晶多型体之一来描述。在接近晶界的地方，晶格常数减小，超晶格发生面外旋转，而纳米晶相对于超晶格的取向保持不变。这些发现可以用释放特定纳米晶-衬底相互作用的代价来解释。在大多数晶界处，相邻纳米晶之间的关联被发现能够经受住结构变化，这意味着获得具有宏观畴尺寸的纳米晶超晶格的关键是与衬底的相互作用得到增强。
