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Author Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. url  doi
openurl 
  Title Electron Bessel beam diffraction for precise and accurate nanoscale strain mapping Type A1 Journal article
  Year (down) 2019 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 114 Issue 24 Pages 243501  
  Keywords A1 Journal article; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT)  
  Abstract Strain has a strong effect on the properties of materials and the performance of electronic devices. Their ever shrinking size translates into a constant demand for accurate and precise measurement methods with a very high spatial resolution. In this regard, transmission electron microscopes are key instruments thanks to their ability to map strain with a subnanometer resolution. Here, we present a method to measure strain at the nanometer scale based on the diffraction of electron Bessel beams. We demonstrate that our method offers a strain sensitivity better than 2.5 × 10−4 and an accuracy of 1.5 × 10−3, competing with, or outperforming, the best existing methods with a simple and easy to use experimental setup.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472599100019 Publication Date 2019-06-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 17 Open Access OpenAccess  
  Notes Deutsche Forschungsgemeinschaft, RO2057/12-2 ; Fonds Wetenschappelijk Onderzoek, G.0934.17N ; Approved Most recent IF: 3.411  
  Call Number EMAT @ emat @UA @ admin @ c:irua:160119 Serial 5181  
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Author Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. doi  openurl
  Title Electron Bessel beam diffraction patterns, line scan of Si/SiGe multilayer Type Dataset
  Year (down) 2019 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:169114 Serial 6865  
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Author Grieb, T.; Krause, F.F.; Schowalter, M.; Zillmann, D.; Sellin, R.; Müller-Caspary, K.; Mahr, C.; Mehrtens, T.; Bimberg, D.; Rosenauer, A. pdf  url
doi  openurl
  Title Strain analysis from nano-beam electron diffraction : influence of specimen tilt and beam convergence Type A1 Journal article
  Year (down) 2018 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 190 Issue 190 Pages 45-57  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Strain analyses from experimental series of nano-beam electron diffraction (NBED) patterns in scanning transmission electron microscopy are performed for different specimen tilts. Simulations of NBED series are presented for which strain analysis gives results that are in accordance with experiment. This consequently allows to study the relation between measured strain and actual underlying strain. A two-tilt method which can be seen as lowest-order electron beam precession is suggested and experimentally implemented. Strain determination from NBED series with increasing beam convergence is performed in combination with the experimental realization of a probe-forming aperture with a cross inside. It is shown that using standard evaluation techniques, the influence of beam convergence on spatial resolution is lower than the influence of sharp rings around the diffraction disc which occur at interfaces and which are caused by the tails of the intensity distribution of the electron probe. (C) 2018 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000432868800006 Publication Date 2018-04-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 1 Open Access OpenAccess  
  Notes ; This work was supported by the German Research Foundation (DFG) under Contracts RO2057/11-1 and RO2057/12-1. ; Approved Most recent IF: 2.843  
  Call Number UA @ lucian @ c:irua:151454 Serial 5041  
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Author Mahr, C.; Müller-Caspary, K.; Graf, M.; Lackmann, A.; Grieb, T.; Schowalter, M.; Krause, F.F.; Mehrtens, T.; Wittstock, A.; Weissmueller, J.; Rosenauer, A. doi  openurl
  Title Measurement of local crystal lattice strain variations in dealloyed nanoporous gold Type A1 Journal article
  Year (down) 2018 Publication Materials research letters Abbreviated Journal Mater Res Lett  
  Volume 6 Issue 1 Pages 84-92  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Reversible macroscopic length changes in nanoporous structures can be achieved by applying electric potentials or by exposing them to different gases or liquids. Thus, these materials are interesting candidates for applications as sensors or actuators. Macroscopic length changes originate from microscopic changes of crystal lattice parameters. In this report, we show spatially resolved measurements of crystal lattice strain in dealloyed nanoporous gold. The results confirm theory by indicating a compression of the lattice along the axis of cylindrically shaped ligaments and an expansion in radial direction. Furthermore, we show that curved npAu surfaces show inward relaxation of the surface layer. [GRAPHICS] .  
  Address  
  Corporate Author Thesis  
  Publisher Taylor & Francis Place of Publication Abingdon Editor  
  Language Wos 000428141500013 Publication Date 2017-11-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2166-3831 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.773 Times cited 4 Open Access Not_Open_Access  
  Notes ; This work has been supported by the Deutsche Forschungsgemeinschaft (DFG) under contracts no. RO2057/12-1 (SP 6), WI4497/1-1 (SP 2) and WE1424/17-1 (SP 3) within the research unit FOR2213 (www.nagocat.de). K.M.-C acknowledges support by the DFG under contract no. MU3660/1-1 and T.G. under contract no. RO2057/ 11-1. ; Approved Most recent IF: 4.773  
  Call Number UA @ lucian @ c:irua:150921 Serial 4973  
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Author Mahr, C.; Kundu, P.; Lackmann, A.; Zanaga, D.; Thiel, K.; Schowalter, M.; Schwan, M.; Bals, S.; Wittstock, A.; Rosenauer, A. pdf  url
doi  openurl
  Title Quantitative determination of residual silver distribution in nanoporous gold and its influence on structure and catalytic performance Type A1 Journal article
  Year (down) 2017 Publication Journal of catalysis Abbreviated Journal J Catal  
  Volume 352 Issue 352 Pages 52-58  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Large efforts have been made trying to understand the origin of the high catalytic activity of dealloyed nanoporous gold as a green catalyst for the selective promotion of chemical reactions at low temperatures. Residual silver, left in the sample after dealloying of a gold-silver alloy, has been shown to have a strong influence on the activity of the catalyst. But the question of how the silver is distributed within the porous structure has not finally been answered yet. We show by quantitative energy dispersive X-ray tomography measurements that silver forms clusters that are distributed irregularly, both on the surface and inside the ligaments building up the porous structure. Furthermore, we find that the role of the residual silver is ambiguous. Whereas CO oxidation is supported by more residual silver, methanol oxidation to methyl formate is hindered. Structural characterisation reveals larger ligaments and pores for decreasing residual silver concentration.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000408299600006 Publication Date 2017-05-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9517 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.844 Times cited 42 Open Access OpenAccess  
  Notes This work was supported by the Deutsche Forschungsgemeinschaft (DFG) under contracts no. RO2057/12-1 (SP 6) and WI4497/1-1 (SP 2) within the research unit FOR2213 (www.nagocat. de) and the European Research Council (ERC Starting Grant No. 335078-COLOURATOMS). (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara Approved Most recent IF: 6.844  
  Call Number EMAT @ emat @c:irua:144434UA @ admin @ c:irua:144434 Serial 4623  
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Author Grieb, T.; Krause, F.F.; Mahr, C.; Zillmann, D.; Müller-Caspary, K.; Schowalter, M.; Rosenauer, A. pdf  doi
openurl 
  Title Optimization of NBED simulations for disc-detection measurements Type A1 Journal article
  Year (down) 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 181 Issue Pages 50-60  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Nano-beam electron diffraction (NBED) is a method which can be applied to measure lattice strain and polarisation fields in strained layer heterostructures and transistors. To investigate precision, accuracy and spatial resolution of such measurements in dependence of properties of the specimen as well as electron optical parameters, simulations of NBED patterns are required which allow to predict the result of common disc-detection algorithms. In this paper we demonstrate by focusing on the detection of the central disc in crystalline silicon that such simulations require to take several experimental characteristics into account in order to obtain results which are comparable to those from experimental NBED patterns. These experimental characteristics are the background intensity, the presence of Poisson noise caused by electron statistics and blurring caused by inelastic scattering and by the transfer quality of the microscope camera. By means of these optimized simulations, different effects of specimen properties on disc detection – such as strain, surface morphology and compositional changes on the nanometer scale – are investigated and discussed in the context of misinterpretation in experimental NBED evaluations. It is shown that changes in surface morphology and chemical composition lead to measured shifts of the central disc in the NBED pattern of tens to hundreds of grad. These shifts are of the same order of magnitude or even larger than shifts that could be caused by an electric polarisation field in the range of MV/cm. (C) 2017 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000411170800006 Publication Date 2017-05-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 6 Open Access Not_Open_Access  
  Notes ; This work was supported by the German Research Foundation (DFG) under Contract No. R02057/11-1, R02057/4-2 and MU3660/1-1. ; Approved Most recent IF: 2.843  
  Call Number UA @ lucian @ c:irua:146725 Serial 4792  
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