Department of Physics and Astronomy, The University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78251, USA.
Nanoscale. 2010 Dec;2(12):2647-51. doi: 10.1039/c0nr00498g. Epub 2010 Oct 13.
We report the formation of Au/Co nanoparticles and their characterization by aberration (Cs) corrected scanning transmission electron microscopy (STEM). The nanoparticles were synthesized by inert gas condensation, forming initially core-shell and bimetallic crystals. However, after thermal treatment at normal atmospheric conditions, the Co nanoparticles changed their morphology into a fine layer forming a perfect interface with the gold. The ordering of the zone rich in Co presents a fcc arrangement matching the gold lattice. The atomic analysis on the interface and the comparison of the STEM images with numerical simulations corroborated the atomic substitution of gold by cobalt.
我们通过像差（Cs）校正扫描透射电子显微镜（STEM）报告了 Au/Co 纳米粒子的形成及其特性。这些纳米粒子是通过惰性气体冷凝形成的，最初形成核壳和双金属晶体。然而，在正常大气条件下进行热处理后，Co 纳米粒子改变了它们的形态，形成了一层精细的层，与金形成了完美的界面。富 Co 区的有序排列呈现出与金晶格匹配的 fcc 排列。界面上的原子分析以及与数值模拟的 STEM 图像比较证实了钴对金的原子取代。
