Virginia TechSitepu, H.2014-07-212014-07-212009-12Sitepu, H., "Texture and structural refinement using neutron diffraction data from molybdite (MoO3) and calcite (CaCO3) powders and a Ni-rich Ni50.7Ti49.30 alloy," Powder Diffr., Vol. 24(4), 2009. DOI: 10.1154/1.32579060885-7156http://hdl.handle.net/10919/49655Preferred 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. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3257906]application/pdfenIn Copyrightpreferred orientationtextureneutron powder diffractionmarch modelgeneralized spherical harmonicsmolybditecalciteti50.70ni49.30shape memory alloyshape-memory alloypreferred orientationrietveld refinementx-raycrystal-structurephasemodeldistributionsintensitiesdensitymaterials science, characterization & testingArticle - Refereedhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8491214&fulltextType=RA&fileId=S0885715600001767https://doi.org/10.1154/1.3257906