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Probing Compositional Order in Atomic Columns: STEM Simulations Beyond the Virtual Crystal Approximation

Published online by Cambridge University Press:  16 December 2019

Douglas A. Blom  and
Thomas Vogt
Douglas A. Blom*
Affiliation:
Department of Chemical Engineering and NanoCenter, University of South Carolina, 715 Sumter St., Room 001, Columbia, SC29208, USA
Thomas Vogt
Affiliation:
Department of Chemistry and Biochemistry and NanoCenter, University of South Carolina, 631 Sumter St., Columbia, SC29208, USA
*
*Author for correspondence: Douglas A. Blom, E-mail: doug.blom@sc.edu
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Abstract

Taking advantage of recent advances in parallel computing, we studied compositional disorder along metal–oxygen atomic columns in a complex Mo,V-oxide bronze using multislice frozen-phonon calculations. Commonly, the virtual crystal approximation (VCA) is used to model compositional disorder at crystallographic sites in a unit cell for a number of different theoretical and experimental techniques. In the VCA, a weighted linear sum of atomic properties is used to approximate the model structure. When using the VCA, the extracted V content of Mo,V–O columns from experimental high-angle annular dark-field (HAADF) images will be about half the V content estimated from simulations, considering the distinct cation ordering. This discrepancy is larger than the spread of HAADF signals of different configurational orders at a given V concentration, which can be up to 20%. Certain “isophilic” atomic arrangements along the column can be distinguished from more random ones using HAADF-STEM imaging. The trends and ratios of the simulated intensity spreads due to different compositional ordering along 11 M–O columns along the c-axis of the Mo,V oxide bronze qualitatively match those observed in experimental HAADF-STEM data. Instrumental and sample-based noise adds to the variability but does not significantly distort the relative ratios of column intensity variation. We observed that we only required seven random configurations to represent the intensity variations along columns.

Keywords

compositional disorderHAADF-STEM imaginginstrumental and sample-based noiseMo,V-bronzemultislice frozen-phonon simulationsvirtual crystal approximation
Type
Materials Science Applications
Information
Microscopy and Microanalysis , Volume 26 , Issue 1 , February 2020 , pp. 46 - 52
Copyright
Copyright © Microscopy Society of America 2019

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References

Blom, DA (2012). Multislice frozen phonon high angle annular dark-field image simulation study of Mo-V-Nb-Te-O complex oxidation catalyst “M1”. Ultramicroscopy 112, 69–75.CrossRefGoogle ScholarPubMed
Blom, DA & Vogt, T (2018). Multi-slice frozen phonon simulations of high-angle annular dark field scanning transmission electron microscopy images of the structurally and compositionally complex Mo-V-Nb-Te oxide catalyst. Adv Struct Chem Imaging 4, 9.CrossRefGoogle ScholarPubMed
Carlino, E & Grillo, V (2005). Atomic-resolution quantitative composition analysis using scanning transmission electron microscopy Z-contrast experiments. Phys Rev B 71, 235303.CrossRefGoogle Scholar
E, H, MacArthur, KE, Pennycook, TJ, Okunishi, E, D'Alfonso, AJ, Lugg, NR, Allen, LJ & Nellist, PD (2013). Probe integrated scattering cross sections in the analysis of atomic resolution HAADF STEM images. Ultramicroscopy 133, 109–119.CrossRefGoogle ScholarPubMed
Esser, BD, Hauser, AJ, Williams, REA, Allen, LJ, Woodward, PM, Yang, FY & McComb, DW (2016). Quantitative STEM imaging of order-disorder phenomena in double perovskite thin films. Phys Rev Lett 117, 176101.CrossRefGoogle ScholarPubMed
Findlay, SD, Shibata, N, Sawada, H, Okunishi, E, Kondo, Y & Ikuhara, Y (2010). Dynamics of annular bright field imaging in scanning transmission electron microscopy. Ultramicroscopy 110, 903–923.CrossRefGoogle ScholarPubMed
Findlay, SD, Shibata, N, Sawada, H, Okunishi, E, Kondo, Y, Yamamoto, T & Ikuhara, Y (2009). Robust atomic resolution imaging of light elements using scanning transmission electron microscopy. Appl Phys Lett 95, 191913.CrossRefGoogle Scholar
Geiser, BP, Kelly, TF, Larson, DJ, Schneir, J & Roberts, JP (2007). Spatial distribution maps for atom probe tomography. Microsc Microanal 13, 437–447.CrossRefGoogle ScholarPubMed
Haider, M, Uhlemann, S, Schwan, E, Rose, H, Kabius, B & Urban, K (1998). Electron microscopy image enhanced. Nature 392, 768–769.CrossRefGoogle Scholar
Hill, R, Blenkinsopp, P, Thompson, S, Vickerman, J & Fletcher, JS (2011). A new time-of-flight SIMS instrument for 3D imaging and analysis. Surf Interface Anal 43, 506–509.CrossRefGoogle Scholar
Holmberg, J, Grasselli, RK & Andersson, A (2004). Catalytic behavior of M1, M2, and M1/M2 physical mixtures of the Mo-V-Nb-Te-oxide system in propane and propene ammoxidation. Appl Catal A 270, 121–134.CrossRefGoogle Scholar
Howie, A (1979). Image contrast and localized signal selection techniques. J Microsc 117, 11–23.CrossRefGoogle Scholar
Jones, L (2016). Quantitative ADF STEM: Acquisition, analysis and interpretation. IOP Conf Ser Mater Sci Eng 109, 012008.CrossRefGoogle Scholar
Kelly, TF, Gibb, TT, Olson, JD, Martens, RL, Shepard, JD, Wiener, SA, Kunicki, TC, Ulfig, RM, Lenz, DR, Strennen, EM, Oltman, E, Bunton, JH & Strait, DR (2004). First data from a commercial local electrode atom probe (LEAP). Microsc Microanal 10, 373–383.CrossRefGoogle Scholar
Kirkland, EJ (2010). Advanced Computing in Electron Microscopy, 2nd ed. New York, NY: Springer.CrossRefGoogle Scholar
Klenov, DO & Stemmer, S (2006). Contributions to the contrast in experimental high-angle annular dark-field images. Ultramicroscopy 106, 889–901.CrossRefGoogle ScholarPubMed
Krivanek, OL, Dellby, N & Lupini, AR (1999). Towards sub-Å electron beams. Ultramicroscopy 78, 1–11.CrossRefGoogle Scholar
Li, X, Buttrey, DJ, Blom, DA & Vogt, T (2011). Improvement of the structural model for the M1 phase Mo-V-Nb-Te-O propane (amm)oxidation catalyst. Top Catal 54, 614–622.CrossRefGoogle Scholar
MacArthur, KE, Brown, HG, Findlay, SD & Allen, LJ (2017). Probing the effect of electron channeling on atomic resolution energy dispersive X-ray quantification. Ultramicroscopy 182, 264–275.CrossRefGoogle Scholar
Momma, K & Izumi, F (2011). VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J Appl Crystallogr 44, 1272–1276.CrossRefGoogle Scholar
Pennycook, SJ & Boatner, LA (1988). Chemically sensitive structure-imaging with a scanning transmission electron microscope. Nature 336, 565–567.CrossRefGoogle Scholar
Pennycook, SJ & Jesson, DE (1990). High-resolution incoherent imaging of crystals. Phys Rev Lett 64, 938–942.CrossRefGoogle ScholarPubMed
Pyrz, WD, Blom, DA, Sadakane, M, Kodato, K, Ueda, W, Vogt, T & Buttrey, DJ (2010 a). Atomic-scale investigation of two-component MoVO complex oxide catalyst using aberration-corrected high-angle annular dark-field imaging. Chem Mater 22, 2033–2040.CrossRefGoogle Scholar
Pyrz, WD, Blom, DA, Sadakane, M, Kodato, K, Ueda, W, Vogt, T & Buttrey, DJ (2010 b). Atomic-level imaging of Mo-V-O complex oxide phase intergrowth, grain boundaries, and defects using HAADF-STEM. Proc Natl Acad Sci USA 107, 6152–6157.CrossRefGoogle ScholarPubMed
Pyrz, WD, Blom, DA, Shiju, NR, Guliants, VV, Vogt, T & Buttrey, DJ (2008 a). Using aberration-corrected STEM imaging to explore chemical and structural variations in the M1 phase of the MoVNbTeO Oxidation Catalyst. J Phys Chem C 112, 10043–10049.CrossRefGoogle Scholar
Pyrz, WD, Blom, DA, Shiju, NR, Guliants, VV, Vogt, T & Buttrey, DJ (2009). The effect of Nb or Ta substitution into the M1 phase of the MoV(Nb,Ta)TeO selective oxidation catalyst. Catal Today 142, 320–328.CrossRefGoogle Scholar
Pyrz, WD, Blom, DA, Vogt, T & Buttrey, DJ (2008 b). Direct imaging of the MoVTeNbO M1 phase using an aberration-corrected high-resolution scanning transmission electron microscope. Angew Chem Int Ed 47, 2788–2791.CrossRefGoogle ScholarPubMed
Rosenauer, A, Mehrtens, T, Müller, K, Gries, K, Schowalter, M, Satyam, PV, Bley, S, Tessarek, C, Hommel, D, Sebald, K, Seyfried, M, Gutowski, J, Avramescu, A, Engl, K & Lutgen, S (2011). Composition mapping in InGaN by scanning transmission electron microscopy. Ultramicroscopy 111, 1316–1327.CrossRefGoogle ScholarPubMed
Sadakane, M, Yamagata, K, Kodato, K, Endo, K, Toriumi, K, Ozawa, Y, Ozeki, T, Nagai, T, Matsui, Y, Sakaguchi, N, Pyrz, WD, Buttrey, DJ, Blom, DA, Vogt, T & Ueda, W (2009). Synthesis of orthorhombic Mo-V-Sb oxide species by assembly of pentagonal Mo6O21 polyoxometalate building blocks. Angew Chem Int Ed 48, 3782–3786.CrossRefGoogle ScholarPubMed
Seyf, HR, Yates, L, Bougher, TL, Graham, S, Cola, BA, Detchprohm, T, Ji, M-H, Kim, J, Dupuis, R, Lv, W & Henry, A (2017). Rethinking phonons: The issue of disorder. npj Comput Mater 49, 1–8.Google Scholar
Towns, J, Cockerill, T, Dahan, M, Foster, I, Gaither, K, Grimshaw, A, Hazlewood, V, Lathrop, S, Lifka, D, Peterson, GD, Roskies, R, Scott, JR & Wilkins-Diehr, N (2014). XSEDE: Accelerating scientific discovery. Comput Sci Eng 16, 62–74.CrossRefGoogle Scholar
Treacy, MMJ (2011). Z dependence of electron scattering by single atoms into annular dark-field detectors. Microsc Microanal 17, 847–858.CrossRefGoogle Scholar
Vogt, T, Blom, DA, Jones, L & Buttrey, DJ (2016). ADF-STEM imaging of nascent phases and extended disorder within the Mo-V-Nb-Te-O catalyst system. Top Catal 59, 1489–1495.CrossRefGoogle Scholar
Wachs, I, Jehng, J-M & Ueda, W (2005). Determination of the chemical nature of active surface sites present on bulk mixed metal oxide catalysts. J Phys Chem B 109, 2275–2284.CrossRefGoogle ScholarPubMed
Wang, ZL (1988). The “frozen-lattice” approach for incoherent phonon excitation in electron scattering. How accurate is it? Acta Crystallogr A 54, 460–467.CrossRefGoogle Scholar
Yamashita, S, Koshiya, S, Nagai, T, Kikkawa, J, Ishizuka, K & Kimoto, K (2015). Quantitative annular dark-field imaging of single-layer graphene- II: Atomic-resolution image contrast. Microscopy 64, 409–418.CrossRefGoogle ScholarPubMed
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