Europe

David RafajaFreiberg University of Mining and TechnologyGermany

rafaja@ww.tu-freiberg.dewww.tu-freiberg.de/allgemein/international/

or www.ww.tu-freiberg.de/~rafaja/

2

Current Trends in Materials Science Related to Powder Diffraction

Investigation of the influence of the real structure and microstructure on the physical (mechanical, electrical, magnetic, optical, thermal) properties of matters

Application of the Rietveld method to the real structure and microstructure analysis

3

Real Structure

Phase composition

Lattice parameters, fractional coordinates and thermal vibrations of atoms Inter-atomic distances Energy bands Changes in the electronic, optical and magnetic properties

4

Microstructure

Preferred orientation of crystallites Enhancement of the crystal anisotropy

Crystallite size and shape Scattering centers for electrons

Structural defects (Dislocations, Stacking faults, Disclinations = local lattice rotations) Scattering centers for electrons

Residual stress Anisotropic changes in the inter-atomic distances

5

Rietveld-like Routines

J. Rodriguez-Carvajal: FULLPROF (structure refinement, quantitative analysis, simplified line profile analysis, magnetic structures)

R. von Dreele: GSAS (structure refinement, quantitative analysis and stress/strain analysis)

V. Petricek: JANA (structure refinement also for incommensurate structures)

J. Bergmann: BGMN (structure refinement, quantitative analysis and stress/strain analysis)

L. Lutterotti: MAUD (structure refinement, quantitative analysis and stress/strain/site analysis)

V. Favre-Nicolin and R. Cerny: FOX (crystal structure solution from powder diffraction by Simulated Annealing Monte Carlo method)

6

Recent Own Results

Diffraction phenomena (coherence effects) in nanocrystalline materials

The XRD recognizes larger crystallites (because of their mutual coherence) and larger microstrain (because of the structure defects at the crystallite’s boundaries) than they really are

These phenomena are pronounced in nanocrystalline materials with a strong preferred orientation

7

Recent Own Results

- 1 - 0 . 5 0 0 . 5 1-1

-0.5

0

0.5

1

Neighboring crystallites are fully coherent Partly coherent Non-coherent

8

Trends in support of science

EU projects Government projects Grant agencies Foundations Industry Institutional resources

Information technologies New materials New technologies Basic research

The resources are assigned to the specific problems of the project.

Databases (in Germany) can be paid either from institutional resources (budget) or from the profit of the service

9

European Conferences 2004

Best Practice Strategies to Identify, Characterize & Control Polymorphism & Crystallization, London, UK, April 21-22, 2004

2nd International Conference on High Performance Structures and Materials (HPSM 2004), Ancona, Italy, May 31 – June 2, 2004, http://www.wessex.ac.uk/conferences/2004/hpsm2004/3.html

VII International School and Symposium on Synchrotron Radiation in Natural Science, Zakopane, Poland, June 8-13, 2004, http://issrns04.us.edu.pl/

Electron Crystallography: Novel Approaches to Structure Determination of Nanosized Materials, Erice, Italy, June 9-20, 2004, http://www.crystalerice.org/2004/ElCryst2004.htm

10

European Conferences 2004

2nd International Conference on Texture and Anisotropy of Polycrystals (ITAP2), Metz, France, July 7-9, 2004, http://194.57.144.1/ITAP2/Itap2_acceuil.htm

Multifunctional and Functionally Graded Materials (FGM2004), Leuven, Belgium, July 11-14, 2004, http://www.fgm2004.com

Diffusion in Materials (DIMAT 2004), Krakow, Poland, July 18-23, 2004, http://www.dimat2004.agh.edu.pl/

The 20th General Conference of the Condensed Matter Division of the European Physical Society, Prague, Czech Republic, July 19-23, 2004, http://cmd.karlov.mff.cuni.cz/CMD/

11

European Conferences 2004

ECM-22, Budapest, Hungary, August 26-31, 2004, http://www.ecm22.mtesz.hu/

EPDIC-9, Prague, Czech Republic, September 2-5, 2004, http://www.xray.cz/epdic/

Size/Strain and Quantitative Phase Analysis Software Workshop (Satellite Meeting of the EPDIC-9), Prague, Czech Republic, September 2, 2004, http://lachlan.bluehaze.com.au/epdic-2004/

Size-Strain IV (Satellite Meeting of the EPDIC-9), Prague, Czech Republic, August 31 – September 2, 2004, http://www.xray.cz/s-s4/

12

European Conferences 2004

7th Biennial Conference on High Resolution X-Ray Diffraction and Imaging (X-TOP), Prague, Czech Republic, September 7-10, 2004, http://www.xray.cz/xtop/

4th International Conference on Inorganic Materials, Antwerp, Belgium, September 19-21, 2004, http://www.im-conference.com

Symposium on Texture and Microstructure Analysis of Functionally Graded Materials (SOTAMA-FGM), Krakow, Poland, October 3-7, 2004, http://www.namam.krakow.pl/sotama/

13

European Conferences 2005

International Conference on Textures of Materials (ICOTOM 14), Leuven, Belgium, July 11-15, 2005, http://www.icotom14.com

XX Congress of IUCr, Florence, Italy, August 23-31, 2005, http://www.iucr2005.it

14

Role of the Powder Diffraction File

Phase Analysis

Building of a Microstructure Model (structure data are necessary)

Rietveld Refinement