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Hafnium-Silicon Precipitate Structure Determination in a New Heat-Resistant Ferritic Alloy by Precession Electron Diffraction Techniques

Published online by Cambridge University Press:  30 October 2013

Désirée Viladot ,
Joaquim Portillo ,
Mauro Gemí ,
Stavros Nicolopoulos  and
Núria Llorca-Isern
Désirée Viladot
Affiliation:
Departament de Ciència de Materials i Enginyeria Metal·lúrgica, Facultat de Química, Universitat de Barcelona, C/Martí i Franquès 1-11, Barcelona 08028, Spain
Joaquim Portillo
Affiliation:
Centres Cientifics i Tecnològics (CCiT), Universitat de Barcelona/Solé i Sabaris 1-3, Barcelona 08028, Spain NanoMEGAS, Boulevard Edmond Machtens 79, Brussels B-1080, Belgium
Mauro Gemí
Affiliation:
Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, Pisa 56127, Italy
Stavros Nicolopoulos
Affiliation:
NanoMEGAS, Boulevard Edmond Machtens 79, Brussels B-1080, Belgium
Núria Llorca-Isern*
Affiliation:
Departament de Ciència de Materials i Enginyeria Metal·lúrgica, Facultat de Química, Universitat de Barcelona, C/Martí i Franquès 1-11, Barcelona 08028, Spain
*
*Corresponding author. E-mail: nullorca@ub.edu
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Abstract

The structure determination of an HfSi4 precipitate has been carried out by a combination of two precession electron diffraction techniques: high precession angle, 2.2°, single pattern collection at eight different zone axes and low precession angle, 0.5°, serial collection of patterns obtained by increasing tilts of 1°. A three-dimensional reconstruction of the associated reciprocal space shows an orthorhombic unit cell with parameters a = 11.4 Å, b = 11.8 Å, c = 14.6 Å, and an extinction condition of (hkl) h + k odd. The merged intensities from the high angle precession patterns have been symmetry tested for possible space groups (SG) fulfilling this condition and a best symmetrization residual found at 18% for SG 65 Cmmm. Use of the SIR2011 direct methods program allowed solving the structure with a structure residual of 18%. The precipitate objects of this study were reproducibly found in a newly implemented alloy, designed according to molecular orbital theory.

Keywords

precession electron diffractionprecession-assisted tomographic diffractioncrystal structure determinationhafnium–silicon precipitate
Type
Materials Applications
Information
Microscopy and Microanalysis , Volume 20 , Issue 1 , February 2014 , pp. 25 - 32
Copyright
Copyright © Microscopy Society of America 2014 

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References

Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G.L., Giacovazzo, C., Mallamo, M., Mazzone, A., Polidori, G. & Spagna, R. (2012). SIR2011: A new package for crystal structure determination and refinement. J Appl Cryst 45, 357–361.CrossRefGoogle Scholar
Gemmi, M., Calestani, G. & Migliori, A. (2002). Strategies in electron diffraction data collection. Adv Imag Elect Phys 123, 311–325.CrossRefGoogle Scholar
Gorelik, T.E., Stewart, A.A. & Kolb, U. (2011). Structure solution with automated electron diffraction tomography data. Different instrumental approaches. J Microsc 244(3), 325–331.CrossRefGoogle ScholarPubMed
Kolb, U., Mugnaioli, E. & Gorelik, T.E. (2011). Automated electron diffraction tomography—a new tool for nano crystal structure analysis. Cryst Res Technol (special issue) 46, 542–554.Google Scholar
Morniroli, J.P. & Ji, G. (2009). Identification of the kinematical forbidden reflections from precession electron diffraction. Materials Research Symposium Proceedings, p. 1184. Materials Research Society. CrossRefGoogle Scholar
Morniroli, J.P., Redjaïmia, A. & Nicolopoulos, S. (2007). Contribution of electron precession to the identification of the space group from microdiffraction patterns. Ultramicroscopy 107, 514–522.Google Scholar
Otten, M.T. (1991). High-angle annular dark-field imaging on a TEM/STEM system. J Elect Microsc Tech 17(2), 221–230.Google Scholar
Own, C.S., Subramanian, A.K. & Marks, L.D. (2004). Quantitative analyses of precession diffraction data for a large cell oxide. Microsc Microanal 10, 96–104.Google Scholar
Petricek, V., Dusek, M. & Palatinus, L. (2006). JANA 2006. The Crystallographic Computing System. Praha, Czech Republic: Institute of Physics.Google Scholar
Rauch, E.F., Véron, M., Portillo, J., Bultreys, D., Maniette, Y. & Nicolopoulos, S. (2008). Automatic crystal orientation and phase mapping in TEM by precession diffraction. Microsc Anal 22, S5.Google Scholar
Sinkler, W. & Marks, L.D. (1999). Application of direct methods for crystal structure determination using strongly dynamical bulk electron diffraction. Mater Charact 42(4-5), 283–295.Google Scholar
Vincent, R. & Midgley, P.A. (1994). Double conical beam-rocking system for measurement of integrated electron diffraction intensities. Ultramicroscopy 53, 271–282.Google Scholar
Weirich, T.E., Portillo, J., Cox, G., Hibst, H. & Nicolopoulos, S. (2006). Ab initio determination of the 393 framework structure of the heavy-metal oxide Csx Nb2.54W2.46O14 from 100 kV precession 394 electron diffraction data. Ultramicroscopy 106, 164–175.CrossRefGoogle Scholar
Zou, X., Hovmöller, S. & Oleynikov, P. (2012). Electron crystallography. Crystallogr Rev 18(4), 253–279.Google Scholar