A key problem of "nanoscience" is understanding what is the origin of the difference in the properties between nano- and single crystals. In contrast to single- for nano-crystals one cannot disregard the fact that there is a large number of atoms located at the surface and, consequently, one has to accept that the crystallographic structure of a very small size particle may deviate from that in the bulk crystals. In a tentative model, a nanocrystal might be presented as a two-phase system formed by the grain core and the surface shell, both having characteristic dimensions.

There are no standard procedures established for performance of structural analysis of a nanocrystal. The problem is that its complex structure cannot be well represented by a unit cell. Only for this reason the methods which are used for elaboration of powder diffraction data based on Bragg equation should not be applied for examination of nanocrystalline materials. The values of lattice parameters calculated from individual Bragg reflection differ between each other, and because they vary with the diffraction vector Q, they are rather "apparent lattice parameters", alp's. Although Bragg equation is not fulfilled for very small crystals, it might be practical to base analysis of real structure of nanocrystals referring to Bragg type scattering and concentrate on interpretation of the deviations of diffraction images of nanocrystals from those corresponding to a perfect crystal lattice.

Examples of examination of distribution of strains among nano-grain core and surface shell has been examined at ambient conditions, but also under high pressures and high temperatures are given based on X-ray and neutron scattering experimental data. Advantages of the analysis referring to reciprocal and real spaces of nano-structures are discussed.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/4219 must be provided.

1. Analysis of density waves in CdSe, SiC, and diamond nanocrystals by application of NanoPDF software package to experimental Pair Distribution Functions.
2. Looking at the real structure of nanocrystals with powder diffraction: the apparent lattice parameter approach
3. Looking beyond limitations of diffraction methods of structural analysis of nanocrystalline materials
4. Dyfraktometryczna analiza mikro- i makro-naprężeń w spiekach i kompozytach otrzymanych pod wysokim ciśnieniem i wysoką temperaturą.
5. Badania własności termicznych nanokryształów metodami dyfraktometrycznymi
6. Nanocrystalline SiC compacts obtained by sintering of laser synthesized nanopowders under extreme pressures
7. Synthesis and properties of GaAs nano-composites
8. MD simulation of atomic structure of nanocrystals
9. SiC-Zn nanocomposites obtained using high-pressure infiltration technique
10. Structural and luminescence properties of yttrium-aluminum garnet (YAG) nanoceramics
11. X-ray diffraction studies of thermal properties of bulk- and surface-atoms of nanocrystalline SiC
12. Characterization of nanostructured hydroxyapatite ceramics densified at high-pressure and temperature
13. Powder precursors for nanoceramics: cleaning and compaction
14. Examination of the atomic Pair Distribution Function (PDF) of SiC nanocrystals by in-situ high pressure diffraction
15. Investigation of the microstructure of SiC-Zn nanocomposites by microscopic methods: SEM, AFM and TEM
16. Sythesis of metal-ceramic nanocomposites by high-pressure infiltration
17. X-Ray Characterization of Nanostructured Materials
18. Generetion and Relaxation of Strain in SiC and GaN under Extreme Pressure
19. Surface Diffraction Effects from Nanopowders under Pressure
20. Influence of high pressure on the polytype structure of nanocrystalline GaN
21. Transformation of fractal microstructure of nanocrystalline SiC and diamond in high pressures - Small Angle Scattering Study