Application of X-ray
Powder Diffraction to Nano-materials - Determination of the
Atomic Structure of Nanocrystals with Relaxed and Strained
Surfaces
B. Palosz A1, E. Grzanka , S.
Gierlotka A1, S. Stel'makh A1, R.
Pielaszek , W. Lojkowski A1, U. Bismayer
A3, J. Neuefeind A4, H.-P Weber
A5, W. Palosz A6
A1 High Pressure Research Center UNIPRESS,
ul. Sokolowska 29/37, 01 142 Warsaw,
Poland
A2 Institute of Experimental
Physics, Warsaw University, ul. Hoza 69, 00 681 Warsaw,
Poland
A3 Mineralogisch-Petrographisches
Institut, Universität Hamburg, Grindelallee 48, D-20146
Hamburg, Germany
A4 HASYLAB at DESY,
Notkestr. 85, D-22603 Hamburg,
Germany
A5 SNBL at ESRF, BP 220, Av des
Martyrs, F-38043 Grenoble,
France
A6 USRA/NASA-Marshall Space Flight
Center, Huntsville, Alabama 35812, USA
Abstract:
The applicability of standard methods for the evaluation of
powder diffraction data of nano-size crystallites is analyzed.
Based on theoretical considerations, it is shown that
deviations of the structure of small particles from the Bragg
approximation on an infinite crystal lattice leads to
significant differences in the diffraction patterns, which may
lead to an erroneous interpretation of the experimental
results. An alternative evaluation of the diffraction data of
nano-particles, based on the so-called "apparent lattice
parameter", alp, is proposed. Based on this method, it
is shown that real nano-crystals constitute a complex,
heterogeneous multi-phase structure.
Keywords:
Nano-crystals, SiC, Surface structure, Diffraction
The references of this article are secured to
subscribers. |