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| Natura: | Artículo científico |
| Lingua: | en |
| Pubblicazione: |
Sociedade Brasileira de Física
2015
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| Accesso online: | https://www.redalyc.org/articulo.oa?id=46433753005 |
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Sommario:
- Microstructural Properties of Chemically Synthesized Cubic ZnS Nanocrystals Kuldeep Deka M. P. C. Kalita Física, Astronomía y Matemáticas Hall Dislocation Lattice strain raydiffraction ZnSnanocrystals In this paper we present microstructural proper- ties of chemically synthesized cubic zinc sulfide (ZnS) nanocrystals, investigated by X-ray diffraction (XRD) line profile analysis applying clas sical Williamson-Hall (WH) and modified Williamson-Hall (MWH) methods, and transmission electron microscopy (TEM) observations. ZnS nanocrystals are synthesized using 1:1 M ratio of Zn and S precursors with 25, 50, and 75 mM, 2- mercaptoethanol as capping agent. WH analyses show that the average crystallite sizes (lattice strain) are 3.98 nm (2.22×10 − 2), 2.69 nm (1.99×10 − 2), and 2.58 nm (2.65×10 − 2). Dislocation contrast factors of ZnS crystals required for the MWH method are calculated from their elastic stiffness constants for various propor- tions of screw and edge dislocations. The best fit to MWH equation is found to be for dislocation contrast factors corresponding to 100 % edge dislocations and thereby suggesting edge dislocations are main contributors to strain. MWH analyses show dislocation density of 3.65, 2.69, and 2.47 nm crystallites are 3.19×10 18 m − 2 ,2.58× 10 18 m − 2 , and 4.62×10 18 m − 2 , respectively. The crystallite sizes as estimated from the WH, MWH, and TEM studies are found to be intercorrelated. Presence of edge disloca- tions, as suggested by the MWH analysis, is confirmed by high resolution TEM (HRTEM) studies. 2015 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46433753005 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.1 Vol.45