Robel István, Lin Xiao-Min, Sprung Michael, Wang Jin
Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA.
J Phys Condens Matter. 2009 Jul 1;21(26):264011. doi: 10.1088/0953-8984/21/26/264011. Epub 2009 Jun 11.
The thermal stability of highly ordered two-dimensional superlattices consisting of dodecanethiol-ligated Au nanoparticles has been investigated using in situ grazing incidence small-angle x-ray scattering in air and in vacuum. In the lower temperature region (<70 °C), annealing in air results in a minimal change of superlattice structure, whereas annealing in vacuum leads to a considerable lattice contraction and a decrease in long-range order. At higher temperatures (>100 °C), ligand desorption causes nanocrystals to sinter locally, destroying quasi-long-range order. The sintering process is significantly enhanced in vacuum compared to the case in air due to the increased desorption rate of thiol ligands under low pressure.
利用原位掠入射小角X射线散射技术，在空气和真空中对由十二烷硫醇连接的金纳米颗粒组成的高度有序二维超晶格的热稳定性进行了研究。在较低温度区域（<70°C），在空气中退火导致超晶格结构变化最小，而在真空中退火则导致晶格显著收缩和长程有序性降低。在较高温度（>100°C）下，配体解吸导致纳米晶体局部烧结，破坏准长程有序。由于低压下硫醇配体解吸速率增加，与在空气中的情况相比，真空中的烧结过程显著增强。
