Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T19:42:47.311Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnetic structure refinement with neutron powder diffraction data using GSAS: A tutorial

Published online by Cambridge University Press:  01 March 2012

J. Cui ,
Q. Huang  and
B. H. Toby
J. Cui
Affiliation:
Materials Analysis and Chemical Sciences, GE Global Research Center, Niskayuna, New York
Q. Huang
Affiliation:
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
B. H. Toby
Affiliation:
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois
Get access Rights & Permissions [Opens in a new window]

Abstract

Neutron diffraction provides a direct probe for the ordering of spins from unpaired electrons in materials with magnetic properties. The ordering of the spins can be modeled in many cases by adding spin directions to standard crystallographic models. This requires, however, that crystallographic space groups be extended by addition of a “color” attribute to symmetry operations, which determines if the operation maintains or flips the direction of a magnetic spin. Rietveld analysis provides a mechanism for fitting magnetic structure models to powder diffraction data. The general structure and analysis system (GSAS) software suite is commonly used for Rietveld analysis and includes the ability to compute magnetic scattering. Different approaches are commonly used within GSAS to create models that include magnetism. Three equivalent but different approaches are presented to provide a tutorial on how magnetic scattering data may be modeled using differing treatment of symmetry. Also discussed is how magnetic models may be visualized. The commands used to run the GSAS programs are summarized within, but are shown in great detail in supplementary web pages.

Keywords

magnetic structureRietveld analysispower diffractioncrystallographic educationneutron scattering
Type
Crystallography Education
Information
Powder Diffraction , Volume 21 , Issue 1 , March 2006 , pp. 71 - 79
Copyright
Copyright © Cambridge University Press 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Billiet, Y., Aroyo, M. I., and Wondratschek, H. (2004). “Tables of maximal subgroups of the space groups,” International Tables for Crystallography, Volume A1: Symmetry Relations Between Space Groups, edited by Wondratschek, H. and Müller, U. (Kluwer, Dordrecht), pp. 153–154.Google Scholar
Brown, P. J. (1995). “Magnetic form factors,” International Tables for Crystallography, Volume C: Mathematical, Physical and Chemical Tables, edited by Wilson, A. J. C. (Kluwer, Dordrecht), pp. 391–398.Google Scholar
Cox, D. (1972). “Neutron-diffraction determination of magnetic structures,” IEEE Trans. Magn. IEMGAQ 10.1109/TMAG.1972.1067272 8, 161.CrossRefGoogle Scholar
Donnay, G., Corliss, L. M., Donnay, J. D. H., Elliott, N., and Hastings, J. M. (1958). “Symmetry of magnetic structures: Magnetic structure of chalcopyrite,” Phys. Rev. PHRVAO 10.1103/PhysRev.112.1917 112, 1917.CrossRefGoogle Scholar
Finger, L. W., Kroeker, M., and Toby, B. H. (2005). Home Page for DRAWxtl <http://www.lwfinger.net/drawxtl>..>Google Scholar
Fultz, B. and Billinge, S. J. L. (2004). DANSE project diffraction software need survey <http://danse.cacr.caltech.edu/polls/results.php?sid=22>..>Google Scholar
Heesch, H. (1930). “Über der vierdimensionalen Gruppen des Dreidimensionalen Raumes,” Z. Kristallogr. ZEKRDZ 73, 325–345.CrossRefGoogle Scholar
Huang, Q., Karen, P., Karen, V. L., Kjekshus, A., Lynn, J. W., Mighell, A. D., Rosov, N., and Santoro, A. (1992). “Neutron-powder-diffraction study of the nuclear and magnetic structures of YBa2Fe3O8 at room temperature,” Phys. Rev. B PRBMDO 10.1103/PhysRevB.45.9611 45, 9611–9619.CrossRefGoogle ScholarPubMed
Iziumov, I. A. and Syromiatnikov, V. N. (1990). Phase transitions and crystal symmetry (Kluwer, Dordrecht, Netherlands).CrossRefGoogle Scholar
Karen, P., Kjekshus, A., Huang, Q., Karen, V. L., Lynn, J. W., Rosov, N., Sora, I. N., and Santoro, A. (2003). “Neutron Powder Diffraction Study of Nuclear and Magnetic Structures of Oxidized and Reduced YBa2Fe3O8+δ,” J. Solid State Chem. JSSCBI 174, 87–95.CrossRefGoogle Scholar
Kovalev, O. V. (1993). Representations of the Crystallographic Space Groups: Irreducible Representations, Induced Representations and Corepresentations (Gordon and Breach, Amsterdam).Google Scholar
Larson, A. C. and Von Dreele, R. B. (2000). Report No. LAUR 86-748. Los Alamos National Laboratory.Google Scholar
Prince, E. (1994). Mathematical Techniques in Crystallography and Materials Science (Springer, New York).CrossRefGoogle Scholar
Rietveld, H. M. (1969). “A profile refinement method for nuclear and magnetic structures,” J. Appl. Crystallogr. JACGAR 10.1107/S0021889869006558 2, 65–71.CrossRefGoogle Scholar
Rodríguez-Carvajal, J. (1993). “Recent advances in magnetic structure determination by neutron powder diffraction,” Physica B PHYBE3 10.1016/0921-4526(93)90108-I 192, 55–69.CrossRefGoogle Scholar
Rodríguez-Carvajal, J. (2004). BasiReps, version 3.70. <ftp://ftp.cea.fr/pub/llb/divers/BasIreps>..>Google Scholar
G., Shirane (1959). “A note on the magnetic intensities of powder neutron diffraction,” Acta Crystallogr. ACCRA9 10.1107/S0365110X59000871 12, 282–285.Google Scholar
Shubnikov, A. V. and Belov, N. V. (1964). Colored Symmetry (Oxford, Pergamon, New York).Google Scholar
Sikora, W., Bialas, F., and Pytlik, L. (2004). “MODY: A program for calculation of symmetry-adapted functions for ordered structures in crystals,” J. Appl. Crystallogr. JACGAR 10.1107/S0021889804021193 37, 1015–1019.CrossRefGoogle Scholar
Stokes, H. T. and Hatch, D. M. (2002). ISOTROPY. <http://stokes.byu.edu/isotropy.html>..>Google Scholar
Toby, B. H. (2001). “EXPGUI, a Graphical User Interface for GSAS,” J. Appl. Crystallogr. JACGAR 10.1107/S0021889801002242 34, 210.CrossRefGoogle Scholar
Vainshtein, B. K. (1996). Fundamentals of Crystals, Symmetry, and Methods of Structural Crystallography (Springer, New York).Google Scholar
Wills, A. S. (2000). “A new protocol for the determination of magnetic structures using simulated annealing and representational analysis (SARAh),” Physica B PHYBE3 10.1016/S0921-4526(99)01722-6 276, 680–681.CrossRefGoogle Scholar
Wills, A. S. (2002). “Symmetry and magnetic structure determination: developments in refinement techniques and examples,” Appl. Phys. A: Mater. Sci. Process. APAMFC 74, S856–S858.CrossRefGoogle Scholar