RMCProfile: reverse Monte Carlo for polycrystalline materials

A new approach to the reverse Monte Carlo analysis of total scattering data from polycrystalline materials is presented. The essential new feature is the incorporation of an explicit analysis of the Bragg peaks using a profile refinement, taking account of the instrument resolution function. Other new features including fitting data from magnetic materials, modelling lattice site disorder and new restraint and constraint options. The new method is demonstrated by a brief review of studies carried out during its development. The new program RMCProfile represents a significant advance in the analysis of polycrystalline total scattering data, especially where the local structure is to be explored within the true constraints of the long-range average structure.

[1]  László Pusztai,et al.  Reverse Monte Carlo modelling of the structure of disordered materials with RMC++ : a new implementation of the algorithm in C++ , 2005 .

[2]  J. S. Evans,et al.  Negative thermal expansion in ZrW2O8: mechanisms, rigid unit modes, and neutron total scattering. , 2005, Physical review letters.

[3]  R. Mcgreevy,et al.  Determination of disordered magnetic structures by RMC modelling of neutron diffraction data , 1991 .

[4]  D. Keen,et al.  Model-independent extraction of dynamical information from powder diffraction data , 2005 .

[5]  C. Shull,et al.  Detection of antiferromagnetism by neutron diffraction , 1949 .

[6]  Martin T. Dove,et al.  Neutron total scattering method: simultaneous determination of long-range and short-range order in disordered materials , 2002 .

[7]  R. Mcgreevy,et al.  RMC: progress, problems and prospects , 1995 .

[8]  G. Shirane.  A NOTE ON THE MAGNETIC INTENSITIES OF POWDER NEUTRON DIFFRACTION , 1959 .

[9]  Mellergård,et al.  Reverse Monte Carlo modelling of neutron powder diffraction data. , 1999, Acta crystallographica. Section A, Foundations of crystallography.

[10]  Simon J. L. Billinge,et al.  Underneath the Bragg Peaks: Structural Analysis of Complex Materials , 2003 .

[11]  R. Mcgreevy,et al.  Modelling of lattice and magnetic thermal disorder in manganese oxide , 1998 .

[12]  Matthew G. Tucker,et al.  High-temperature, structural disorder, phase transitions, and piezoelectric properties of GaPO4 , 2006 .

[13]  S. Wells,et al.  Reverse Monte Carlo with geometric analysis – RMC+GA , 2004 .

[14]  D. Keen,et al.  Erratum: Phonons from Powder Diffraction: A Quantitative Model-Independent Evaluation [Phys. Rev. Lett. 93, 075502 (2004)] , 2005 .

[15]  G. S. Pawley,et al.  Unit-cell refinement from powder diffraction scans , 1981 .

[16]  Martin T. Dove,et al.  Application of the reverse Monte Carlo method to crystalline materials , 2001 .

[17]  Armel Le Bail,et al.  Ab-initio structure determination of LiSbWO6 by X-ray powder diffraction , 1988 .

[18]  S. Wells,et al.  Total scattering and reverse Monte Carlo study of the 105 K displacive phase transition in strontium titanate , 2005 .

[19]  Alex C. Hannon,et al.  Results on disordered materials from the GEneral Materials diffractometer, GEM, at ISIS ☆ , 2005 .

[20]  R. Ibberson,et al.  GEM — General materials diffractometer at ISIS , 1997 .

[21]  D. Keen,et al.  Phonons from powder diffraction: a quantitative model-independent evaluation. , 2004, Physical review letters.

[22]  I. Blech,et al.  SPIN CORRELATIONS IN MnO , 1964 .

[23]  Martin T. Dove,et al.  Reverse Monte Carlo modelling of crystalline disorder , 2005 .

[24]  W. Roth.  Magnetic Structures of MnO, FeO, CoO, and NiO , 1958 .

[25]  V. F. Sears,et al.  Neutron diffraction study of the plastic phases of polycrystalline SF6 and CBr4 , 1979 .

[26]  R. L. McGreevy,et al.  Reverse Monte Carlo Simulation: A New Technique for the Determination of Disordered Structures , 1988 .

[27]  D. Keen.  Refining disordered structural models using reverse monte carlo methods: Application to vitreous silica , 1997 .

[28]  D. Keen.  A comparison of various commonly used correlation functions for describing total scattering , 2001 .

[29]  A. Soper,et al.  Scientific Reviews: GEM: The General Materials Diffractometer at ISIS-Multibank Capabilities for Studying Crystalline and Disordered Materials , 2004 .

[30]  H. Rietveld.  A profile refinement method for nuclear and magnetic structures , 1969 .

[31]  Martin T. Dove,et al.  Refinement of the Si–O–Si bond angle distribution in vitreous silica , 2005 .

[32]  D. Keen,et al.  Magnetic structure of MnO at 10 K from total neutron scattering data. , 2006, Physical review letters.

[33]  Shaked,et al.  Low-temperature magnetic structure of MnO: A high-resolution neutron-diffraction study. , 1988, Physical review. B, Condensed matter.