Kumpf C, Neder R B, Niederdraenk F, Luczak P, Stahl A, Scheuermann M, Joshi S, Kulkarni S K, Barglik-Chory C, Heske C, Umbach E
Lehrstuhl für Experimentelle Physik II, Universität Würzburg, D-97074 Würzburg, Germany.
J Chem Phys. 2005 Dec 8;123(22):224707. doi: 10.1063/1.2129369.
We introduce a modified method of powder-diffraction data analysis to obtain precise structural information on freestanding ZnS and CdS nanoparticles with diameters well below 5 nm, i.e., in a range where common bulk-derived approaches fail. The method is based on the Debye equation and allows us to access the crystal structure and the size of the particles with high precision. Detailed information on strain, relaxation effects, stacking faults, and the shape of the particles becomes available. We find significant size differences between our new results and those obtained by established methods, and conclude that a mixed zinc-blende/wurtzite stacking and significant lattice distortions occur in our CdS nanoparticles. Our approach should have direct impact on the understanding and modeling of quantum size effects in nanoparticles.
我们介绍了一种改进的粉末衍射数据分析方法，以获取直径远低于5nm的独立ZnS和CdS纳米颗粒的精确结构信息，即在常见的基于体相的方法失效的范围内。该方法基于德拜方程，使我们能够高精度地获取颗粒的晶体结构和尺寸。关于应变、弛豫效应、堆垛层错和颗粒形状的详细信息也可获得。我们发现我们的新结果与通过既定方法获得的结果之间存在显著的尺寸差异，并得出结论，我们的CdS纳米颗粒中存在闪锌矿/纤锌矿混合堆积和明显的晶格畸变。我们的方法应该对理解和模拟纳米颗粒中的量子尺寸效应有直接影响。
