Dear all, The ILL is organising the 2nd Annual School on Advanced Neutron Diffraction Data Treatment using the FullProf Suite. The registration is already open and we would like to invite you to submit candidatures and to give the maximum diffusion in your institutes.
Those interested can find more information in the ILL web site: http://www.ill.eu/news-events/events/ where the programme is now available. Many thanks in advance for helping in the diffusion of this information. Best regards, The local organizing committee of FPSchool - 2009 Juan RODRIGUEZ-CARVAJAL, [EMAIL PROTECTED] Marie-Hélène LEMÉE-CAILLEAU, [EMAIL PROTECTED] Gabriel CUELLO, [EMAIL PROTECTED] _________________________________________________________________________ FPSchool - 2009 2nd ILL annual school on Advanced Neutron Diffraction Data Treatement using the FULLPROF Suite 26-30 January 2009 Grenoble, France. Email: [EMAIL PROTECTED] URL: http://www.ill.eu/dif/FPSchool/ _________________________________________________________________________ Programme 26/01/2009 1 General introduction to the programs of the FullProf Suite. Web site: downloading the suite and individual programs. The use of the FPS_Toolbar for accessing the programs. Consulting the manuals and documentation. 2 Use of the program WinPLOTR for visualising diffraction patterns, peak detection and peak fit, exporting background, visualisation of 3D plots, 2D detectors, etc. 3 Indexing powder diffraction patterns (with the indexing programs: DICVOL04, TREOR-90, etc). 4 Determination of propagation vectors of superstructures and incommensurate magnetic structures. Programs: SuperCell and k_Search. Practical session Format of diffraction pattern files, superposition of diffraction patterns using a common scattering variable (Q-space, d-space, s-space) when the original diffraction patterns are in 2theta-space or time-of-flight-space. How to save selected peaks and/or background for indexing programs. Running the programs from the FPS_Toolbar or from WinPLOTR. The use of EdPCR and text editors. Importing CIF files. 27/01/2009 5 Introduction to the mathematical description of powder diffraction patterns. Peak shapes. Instrumental resolution of constant wavelength and time-of-flight neutron powder diffractometers. Sample contribution to broadening (microstructure). 6 Refinement of powder diffraction patterns without structural model. Pawley and Le Bail methods. Limitations and pitfalls. 7 Ab-initio structure determination using powder diffraction. Direct methods (XLENS), real-space methods (Monte Carlo and simulated annealing). Practical session Using WINPLOTR for fitting zones of the diffraction pattern. Setting up an instrumental resolution file. Using the Le Bail method for extracting integrated intensities. Preparation of integrated intensity files to be used by the simulated annealing method implemented in FullProf or for using XLENS. Simple examples of crystal structure determination. 28/01/2009 8 Introduction to the Rietveld method. The limitations of the least-squares optimisation method. Structural models: the expressions of structure factors in the case of simple crystal structures, magnetic structures, rigid-body, special form factors. Symmetry-adapted modes. Free parameters of the structural model and information contained in powder diffraction patterns. Agreement indices and graphic output. 9 Strategy for Rietveld refinements. Behaviour of the program under an excess of free parameters. The use of constraints and restraints. Inspection of the difference curve, interpretation of the different features. 10 Post-refinement calculations: Distances, angles and Bond-Valence sums (programs: Bond_Str and GBond_Str). The programs Fourier and GFourier. Visualisation of structures using FullProf Studio. Practical session Setting up an input control file for FullProf. Automatic modes of refinement. Hints and tricks. Using the simulated annealing method implemented in FullProf. Training using example files distributed within the FullProf Suite. Complete treatment of a case problem: solving and refining the crystal structure of a perovskite-like material, using x-ray and neutron diffraction data. The use of instrumental resolution function files. Combined refinements. Multi-phase refinements. 29/01/2009 (Special topic: Magnetic Structures I) 11 Magnetic structures. Description using the formalism of propagation vectors. Symmetry analysis: Magnetic Space Group and Representation theory. The magnetic Bragg intensities: magnetic interaction vector and magnetic structure factor. Polarised neutrons. Blume equations. Powder and single-crystal magnetic diffraction. Domains. 3D polarimetry. 12 Magnetic structure determination using powder diffraction. Simulated Annealing. Limitations of powder diffraction. Examples of magnetic structure determination: commensurate and incommensurate structures. Magnetic structure refinements. Sequential refinements. Practical session Complete examples of magnetic structure determination and refinement using powder diffraction. Setting-up of magnetic structure refinements for single crystal work. Using WinPLOTR (under Windows) for visualising the sequential refinement results. 30/01/2009 (Special topic: Magnetic structures II) 13 Symmetry and magnetism. Magnetic space groups and representation analysis (cont.). The use of the program BasIreps. Examples and issues. Interpretation of magnetic structures in terms of exchange interactions. Use of utility programs: Simbo, Enermag. 14 Refinement of single crystal data using FullProf. How to handle the problem of domains. The use of DataRed for data reduction. Spin densities: refinement of Flipping ratios using FullProf. Practical session Sequential refinements of magnetic structures. Spin reorientations. Complete treatment of a case problem: solving and refining the magnetic structure of a perovskite-like material. Incommensurate magnetic structures. Single crystals.
