ResearchBib Share Your Research, Maximize Your Social Impacts
Sign for Notice Everyday Sign up >> Login

Application of electron crystallography to structure characterization of ZnS nanocrystals

Journal: Journal of Analytical Science and Technology (JAST) (Vol.2, No. 2)

Publication Date:

Authors : ;

Page : 91-96

Keywords : electron crystallography; ZnS; nanocrystals; energy-filtered electron powder diffraction; high resolution transmission electron microscopy;

Source : Downloadexternal Find it from : Google Scholarexternal

Abstract

We chracterized the structure properties of two types of ZnS nanocrystals by electron crystallography. X-ray diffraction analysis for these ZnS nanocrystals was performed to determine their initial structures. Their crystallite sizes were about 5.9 nm and 8.1 nm and their crystal systems were hexagonal and cubic, respectively. Their atomic structures, however, could not be determined because of the weak diffraction intensities as well as the unexpected intensities from impurty. To overcome these problems, the structures of ZnS nanocrystals were resolved by electron crystallography using EF-EPD (energy-filtered electron powder diffraction) and HRTEM (high resolution transmission electron microscopy) methods. The structrues determined by Rietveld analysis are Pmc (a = 3.8452 Å, c = 18.5453 Å) and F-43m (a = 5.4356 Å), respectively. Their crystallite shapes were nanorods and quasi-nanoparticles and the nanorod crystal were grown along the [001] direction. It was revealed that the phase transformation between the cubic sphalerite to the hexagonal wurtzite structure of ZnS nanocrytals was related to their shapes and growth mechanism. Electron cryststallogrpahy, employing EF-EPD and HRTEM methods together, has advantages for structure analysis and property chracterization of nano-sized materials.

Last modified: 2012-11-07 23:12:33