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What is FullProf ?
Juan Rodríguez-Carvajal
Laboratoire Léon Brillouin (CEA-CNRS),
Centre d’Etudes de Saclay
91191 Gif sur Yvette Cedex (France)
Email: [email protected]
Thierry Roisnel
Laboratoire de Chimie du Solide et Inorganique Moléculaire
Université de Rennes 1 (France)
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
What’s FullProf ?
•
A program for :
Simulation of powder diffraction patterns
Pattern decompositionÖ integrated intensities
Structure refinement
Powder and single crystal data
•
Crystal and magnetic structures
•
Multiple data sets: simultaneous treatment of several
powder diffraction patterns (CW X-rays & neutrons,
Energy dispersive X-rays, TOF neutron diffraction)
•
Combined treatment of single crystal and powder data
•
Structure determination capabilities: simulated annealing
on integrated intensity data
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Features of FullProf
• Choice of peak shape for each phase
• Background: fixed, refinable points, polynomial function,
Fourier series …
• Multi phase (up to 16 phases)
• Preferential orientation
• Absorption correction for cylinder and flat plate sample
shape
• hkl dependence FWHM for strain and size effects
• Quantitative analysis
• Atomic distances and angles calculations
• Rigid Body description
• …
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
A few words of history …(1)
• Origins: DBW program, 1981 in Barcelona (thanks to Ray Young)
• Reorganization towards a structured programming within the
FORTRAN 77 language, corrections of bugs, different ways
of calculating R-factors, etc. Barcelona/Grenoble (1982-1987)
• Introduction of magnetic scattering, anisotropic broadening,
profile matching (now known as Le Bail method), rigid bodies
1988-1992, Institute Laue-Langevin, Grenoble.
The name FullProf is adopted in 1990
"FULLPROF: A Program for Rietveld Refinement and Pattern Matching Analysis"
J. Rodríguez-Carvajal
Powder Diffraction, Satellite meeting of the XV congress of the International
Union of Crystallography, Toulouse 16-19 July (1990)
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
A few words of history …(2)
• Improvements of magnetic scattering options, new peak shapes,
single crystal and integrated intensities options, ...
Distribution by anonymous ftp in 1993. LLB, Orsay (near Paris)
• Introduction of a rudimentary option for handling Time of Flight
neutron powder diffraction data in 1996.
• WinPLOTR and Windows version of FullProf, distribution via
the LLB Web site. Progressive conversion to Fortran 90 style
and conventions (1998).
• Complete reorganization of the code within the new Fortran 90
language. Programmed in the subset ELF90. Multiple data sets,
TOF improvements (Barcelona, Argonne, Orsay, 1999 …)
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
FullProf Web site:
http://www-llb.cea.fr/fullweb/fp2k/fp2k.htm
or
ftp://ftp.cea.fr/pub/llb/divers/
Basireps
Rietveld-Exercises
fullprof.2k
fullprof_examples
fullprof_exercises
tutorials
winplotr
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
New FullProf Web site:
http://valmap.dfis.ull.es/fullprof/
under construction …
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
How works FullProf
Minimal input:
Input control file (extension ‘ .pcr ’): PCR-file
Model, crystallographic/magnetic information
PCR file
FullProf
DAT file(s)
Output
files,
Plot
diffr.
patterns
Eventually, experimental data
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
The PCR file: steep learning curve
DAT file(s)
PCR file
Format depending on the
instrument, usually simple
Ä Many variables and options
Ä Complex to handle
Ä Hint: copy an existing
(working) PCR-file and modify
it for the user case, or...
Ä USE the new GUI: EdPCR
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Output files created by FullProf
¾ .OUT
output file of the calculation: details of refinement,
correlation matrix, intensities, FWHM, 2θH, …
¾ .SUM
summary of the .OUT file
¾ .BAC
background file
¾ .PRF
Yobs, Ycalc, Yobs-Ycalc, 2θΗ
¾ .RPA
summary of refined parameters
¾ .SYM
list of symmetry operators
¾ .FOU
hkl and F2 list for Fourier maps
¾ .HKL
complete list of reflections for each phase
¾ .MIC
microstructural information
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Last minute changes in FullProf
Documented in “fp2k.inf”
-------------------------------------------------------------------------In this file new features, as well as discovered bugs, of FullProf.2k
are periodically documented. For details consult the manual of FullProf.
From 10 May 2003, comments on the programs constituting the FullProf suite
are also provided.
Juan Rodriguez-Carvajal (Laboratoire Leon Brillouin, Saclay)
---------------------------------------------------------------------------------------28 July 2003
--------------- An updated version of FullProf.2k is now available.
. . . . . . . . .
- Some changes have been introduced for treating the background:
(1) The polynomial background of 12 coefficients, for constant wavelength case, has been
changed so that the last three coefficients correspond to inverse powers of 2theta.
. . . . . . .
(2) Now there is the possibility to include several previously calculated profiles as
contributing, through a linear combination, to the background of a powder diffraction
pattern. The individual profiles are read in input files named "filedat_n.bac". Where
"filedat" is the code of the data file corresponding to a diffraction pattern and the
index "n" is the number of the contributing profile. The additional contribution to
the background is calculated as:
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
The Rietveld Method in practice (1)
Least squares minimization technique Î local minima
Some prescriptions to avoid divergence of refinement:
¾ Well knowledge of the diffractometer:
. First of all, determine the Instrumental Resolution Function
(IRF): evolution of shape and FWHM versus scattering variable, for the
diffractometer setup (monochromator adjusting, collimation slits …)
¾ Use the best possible starting model:
. Background parameters
. Lattice constants
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Can be previously
refined from whole
pattern fitting
The Rietveld Method in practice (2)
¾Do not start by refining all parameters as the same time !
1- scale factor
2- + zero shift of detector, 1st background parameter and lattice parameters
3- + atomic positions, overall Debye-Waller factor
4- + PSF, asymmetry parameters
5- + atom occupancies (if required)
6- + individual isotropic thermal parameters
7- + additional background parameters
8- + instrumental or physical aberrations
¾ In all cases, it is essential to plot frequently the calculated and
experimental patterns: examination of the difference plot is a quick
and efficient method to detect blunders in the model or in the input
file which control the refinement process
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Total-pattern fitting (profile matching)
JBT=2
¾ No structural information (i.e. atomic positions) is needed, except
space group and approximate cell parameters
* the scale factor is fixed (any particular value)
* integrated intensities are free parameters and refined individually,
using iteratively the Rietveld formula for getting the “observed”
intensities:
Starting from crudely estimated Ih(n=0), the new intensity at cycle (n+1)
are calculated as:
 yiobs − ybi 
I h (n ) = ∑ I h (n − 1) .Ωi ,h .  calc

i
 yi − ybi 
•others parameters (cell parameters, zero shift, PSF, asymmetry …) are
refined by the usual L.S. procedure
This whole profile fitting procedure leads to a list of integrated
intensities: this method is thus a convenient first step (actually
the best!) for structure determination from powder data.
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Total-pattern fitting (profile matching)
JBT=2
¾ Some recommendations:
* 1st refinement run (~10 cycles):
. IRF_n = 0 for each phase
. Number of refined parameters = 0
* if the 1st step is satisfactory (see plot) Least squares
refined parameters: zeroshift, cell parameters, background …
¾ Important points:
* all hkl reflections permitted by the space group are considered and
included in the refinement, even if the reflections are not observed !
* in case of severe overlap of reflections and poor reliability starting
parameters, it is wise to start with low angle reflections (without
refining FWHM parameters) and progressively increase the angular
range.
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Hint’s trick
¾ Limited number of measured reflections:
* select refined parameters
* fix some parameters to physically reasonable values
¾ Start with standard profile parameters of your
instrument
¾ Examine carefully the difference pattern with a
plotting program
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
FullProf examples: content of pcr_dat.zip
ftp://ftp.cea.fr/pub/llb/divers/fullprof_examples/pcr_dat.zip
Crystallographic structures:
* conventional X-rays diffraction pattern
CeO2
ce*.*
mixture of rutile and anatase:
rutana.*
Tb2BaCoO5(R.M. and profile matching) tbbaco.dat
pbsox.dat
PbSO4
* neutrons:
pbso4.dat
PbSO4
ybacud1a.dat
Y0.9Ca0.1Ba2Cu3O7
Magnetic structures:
hobk.dat
Ho2BaNiO5
dy.dat
DyMn6Ge6
Strain refinement:
la.dat
La2NiO4
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
FullProf refinement codewords
For each refined parameter, the codeword Cx is formed as:
Cx = sign(a) . (10p + abs(a))
p:
a:
ordinal number of the parameter x (1 <= p <= MAXS)
multiplier factor (necessary to include rigid constraints
between refine parameters)
Note: recent versions of FullProf
aut=1
(from 2000)
. automatic renumbering of refined parameters
. manually numbering for constrained parameters
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Tutorials and documentation
¾ Introduction to the program FullProf
ftp://ftp.cea.fr/pub/llb/divers/tutorials/fpjdn.ps
¾ Structural Analysis from Powder Diffraction Data: the
Rietveld Method
ftp://ftp.cea.fr/pub/llb/divers/tutorials/jdn_97.pdf
¾ FullProf user’s guide distributed with FullProf
fp2k.inf, FullProf.ins, fullprof_manual.pdf
¾ Other PDF documents and exercises in ZIP files at
ftp://ftp.cea.fr/pub/llb/divers/Rietveld-Exercises
ftp://ftp.cea.fr/pub/llb/divers/fullprof_exercises
ftp://ftp.cea.fr/pub/llb/divers/fullprof_examples
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Tutorials and documentation (Español)
Francisco Cruz Gandarilla y Mateo Jergel
http://www.esfm.ipn.mx
⇓
Postgrado
⇓
Postgrado en C. de Materiales.
⇓
Planta Docente.
⇓
Cruz Gandarilla , Francisco.
⇓
Aplicaciones de la difracción de Rayos- X.1.6
What’s FullProf ? T.R. (Mexico 21-25 June 2004)
Acceso directo:
http://www.esfm.ipn.mx/sepi/poscmat/AplicacRayosX1.6
El curso se concibió de forma tal de que sus notas pudieran ser
distribuidas de forma libre entre los estudiantes y que sirviera a
todos aquellos que se inician en la difracción de rayos X en Ciencia
de Materiales. Si algún docente se interesa en utilizar las mismas en
sus cursos solo le rogamos enviar una carta de constancia a nombre
de los profesores del curso.
Francisco Cruz
Mateo Jergel
What’s FullProf ? T.R. (Mexico 21-25 June 2004)