@conference{
author = "Nikolic, Nenad and Šćepanović, Maja and Grujić-Brojčin, Mirjana and Vojisavljević, Katarina and Sreckovic, Tatjana",
year = "2019",
abstract = "Mechanical activation (MA), as a simple and low-cost method for modifying
physico-chemical properties of disperse systems, is often used for obtaining
powders. Prolonged milling in high-energy mills, necessary for obtaining
nanoparticles, leads to contamination of the starting material, and it can be used as
an additional route for introducing the milling assembly material as the desired
dopant into a powder.
In the present work morphological and structural characteristics of ZnO nanopowders
obtained by MA in a high-energy planetary ball mill with stainless steel
(Fe), Y-stabilized zirconium oxide (Zr) and tungsten carbide (W) vials and balls
were investigated. Knowing that microstructural characteristics of mechanically
milled ZnO powder have strongly depended on milling conditions. The milling has
been performed in a continual regime in air, with following conditions: the rotation
speed of the disk was 400 rpm, ball-to-powder mass ratio was 40:1, and milling time
was 300 min. The samples were characterized by scanning electron microscopy
(SEM), equipped with an EDS, X-ray diffraction (XRD), Raman and UV-vis
spectroscopy. In order to investigate the type of intrinsic defects and impurities
introduced by milling, both milled and thermally treated milled ZnO were analyzed.
According to the SEM, the particles of various sizes (100–500 nm) were present
in the sample before milling. After milling significant changes in particle shapes and
sizes and very pronounced tendency to adhesion in agglomerates, with dimensions
in the range of submicron up to a few micrometers, has been noticed.\
The phase analysis of both milled and thermally treated milled samples of
powders indicates the presence of wurtzite ZnO refined in P63mc space group [1].
The XRD patterns of milled samples of Fe-, W- and Zr-doped ZnO do not reveal the
presence of other ZnO phases. On other side, in thermally treated milled samples of
W- and Fe-doped ZnO the ZnWO4 (samartinite, P2/c) and cubic spinel (Fd-3m) are
present, respectively. In thermally treated milled Zr-doped sample monoclinic and
tetragonal ZrO2 (P21/c and P42/nmc) are present, whereas ZnZrO3 structures could
not be refined due to very low peak intensities [2].
1. M. Šćepanović, M. Grujić-Brojčin, et al., J. Raman Spectrosc., 41 (2010) 914
2. K. Vojisavljević, M. Šćepanović, et al., J. Phys.: Condens. Matter, 20 (2008) 475202",
publisher = "Institute for Multidisciplinary Research, University of Belgrade",
journal = "5th Conference of Serbian Society for Ceramic Materials",
title = "THE EFFECTS OF MILLING MEDIA ON MORPHOLOGICAL AND STRUCTURAL CHANGES IN MECHANICALLY ACTIVATED ZnO",
pages = "87-87",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2313"
}
