Abstract
For stabilized nanoparticles of cadmium sulfide, a highly resolved radial distribution function was derived from the dispersion curve of synchrotron radiation (λ = 0.08824 Å). The nanoparticle core has dimensions of 15 Å-20 Å and consists of Cd and S atoms in a 1:1 ratio. In the inner part of the nanoparticle, these atoms have a random tetrahedral coordination similar to that in crystalline CdS. Half of all core S atoms belong to the ligands and are coordinated by the surface Cd atoms. In contrast to the inner S atoms, these S atoms each binds two or three Cd atoms, forming a CdSCd bond angle of ≈100°, which is smaller than the tetrahedral angle. The Cd-S bond lengths are similar for both types of sulfur and vary within 2.52 Å-2.53 Å. The spatial arrangement of the Cd and S atoms beyond the first coordination sphere is significantly different from that of bulk CdS, which may be caused by perturbations induced by the surface S atoms.
| Original language | English |
|---|---|
| Pages (from-to) | 427-436 |
| Number of pages | 10 |
| Journal | Journal of Structural Chemistry |
| Volume | 45 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 2004 |
| Externally published | Yes |
Funding
Hence it should be noted that the estimated size of the nanoparticle core given in the beginning of the section is the lower bound due to the additional decay of the RDF peaks caused by poor ordering of Cd and S atoms in the core. At a radius of 15 Å-20 Å, the correlations between atomic positions may fade out, while the physical size of the nanoparticle can be somewhat larger. This is evidenced by the lack of the shortest CdS separations required for reconstructing the first RDF peak for small models approximately 15 Å in size. This work was supported by DFG grant No. SFB 410.
| Funders | Funder number |
|---|---|
| Deutsche Forschungsgemeinschaft | SFB 410 |
Keywords
- Diffraction
- Nanocrystals
- Nanostructures
- Radial distribution function
- Short-range order
- Structure
- Synchrotron radiation