Texture and structural refinement using neutron diffraction data from molybdite (MoO3) and calcite (CaCO3) powders and a Ni-rich Ni50.7Ti49.30alloy
- 1 December 2009
- journal article
- Published by Cambridge University Press (CUP) in Powder Diffraction
- Vol. 24 (4), 315-326
- https://doi.org/10.1154/1.3257906
Abstract
Preferred orientation or texture is a common feature of experimental powder patterns. The mathematics of two commonly used models for preferred orientation—the March-Dollase and the generalized spherical-harmonic models—is reviewed. Both models were applied individually to neutron powder data from uniaxially pressed molybdite (MoO3) and calcite (CaCO3) powders in Rietveld analyses, as well as the as-received powders. The structural refinement results are compared to single-crystal structures. The results indicate that reasonable refinement of crystal structures can be obtained using either the March model or generalized spherical-harmonic description. However, the generalized spherical-harmonic description provided better Rietveld fits than the March model for the molybdite and calcite. Therefore, the generalized spherical-harmonic description is recommended for correction of preferred orientation in neutron diffraction analysis for both crystal structure refinement and phase composition analysis. Subsequently, the generalized spherical-harmonic description is extended to crystal structure refinement of annealed and the aged polycrystalline Ni-rich Ni50.7Ti49.30 shape memory alloys.This publication has 32 references indexed in Scilit:
- In situ structural and texture analyses of monoclinic phase for polycrystalline Ni-rich Ti49.86Ni50.14 alloy from neutron diffraction dataPowder Diffraction, 2008
- Structural refinement of neutron powder diffraction data of two-stage martensitic phase transformations in Ti50.75Ni47.75Fe1.50 shape memory alloyPowder Diffraction, 2007
- Physical metallurgy of Ti–Ni-based shape memory alloysProgress in Materials Science, 2005
- R-Phase Structure Refinement Using Electron Diffraction DataMATERIALS TRANSACTIONS, 2002
- Electron density and optical anisotropy in rhombohedral carbonates. III. Synchrotron X-ray studies of CaCO3, MgCO3 and MnCO3Acta crystallographica Section B, Structural science, crystal engineering and materials, 1995
- Some basic concepts of texture analysis and comparison of three methods to calculate orientation distributions from pole figuresJournal of Applied Crystallography, 1988
- Correction of intensities for preferred orientation in powder diffractometry: application of the March modelJournal of Applied Crystallography, 1986
- Strain modification of angular density distributionsTectonophysics, 1973
- A profile refinement method for nuclear and magnetic structuresJournal of Applied Crystallography, 1969
- Crystal Structure and a Unique ``Martensitic'' Transition of TiNiJournal of Applied Physics, 1965