|   | 
Details
   web
Records
Author Li, K.; Idrissi, H.; Sha, G.; Song, M.; Lu, J.; Shi, H.; Wang, W.; Ringer, S.P.; Du, Y.; Schryvers, D.
Title Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys Type A1 Journal article
Year 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 118 Issue 118 Pages 352-362
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cut by the foil surface. The method can be performed on a regular foil specimen with a modem LaB6 or field-emission-gun transmission electron microscope. Precisions around +/- 16% have been obtained for precipitate volume fractions of needle-like beta ''/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is dose to that directly obtained using 3DAP analysis by a misfit of 45%, and the estimated precision for number density measurement is about +/- 11%. The limitations of the method are also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000383292000042 Publication Date 2016-06-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.714 Times cited 9 Open Access
Notes This work is financially supported by National Natural Science Foundation of China (51501230 and 51531009) and Postdoctoral Science Foundation of Central South University (502042057). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21 and FWO project G.0576.09N. Approved Most recent IF: 2.714
Call Number EMAT @ emat @ c:irua:137171 Serial 4334
Permanent link to this record
 

 
Author Du, C.; Hoefnagels, J.P.M.; Kolling, S.; Geers, M.G.D.; Sietsma, J.; Petrov, R.; Bliznuk, V.; Koenraad, P.M.; Schryvers, D.; Amin-Ahmadi, B.
Title Martensite crystallography and chemistry in dual phase and fully martensitic steels Type A1 Journal article
Year 2018 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 139 Issue Pages 411-420
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Lath martensite is important in industry because it is the key strengthening component in many advanced high strength steels. The study of crystallography and chemistry of lath martensite is extensive in the literature, however, mostly based on fully martensitic steels. In this work, lath martensite in dual phase steels is investigated with a focus on the substructure identification of the martensite islands and microstructural bands using electron backscattered diffraction, and on the influence of the accompanied tempering process during industrial coating process on the distribution of alloying elements using atom probe tomography. Unlike findings for the fully martensitic steels, no martensite islands with all 24 Kurdjumov-Sachs variants have been observed. Almost all martensite islands contain only one main packet with all six variants and minor variants from the remaining three packets of the same prior austenite grain. Similarly, the martensite bands are typically composed of connected domains originating from prior austenite grains, each containing one main packets (mostly with all variants) and few separate variants. The effect of tempering at similar to 450 degrees C (due to the industrial zinc coating process) has also been investigated. The results show a strong carbon partitioning to lath boundaries and Cottrell atmospheres at dislocation core regions due to the thermal process of coating. In contrast, auto-tempering contributes to the carbon redistribution only in a limited manner. The substitutional elements are all homogenously distributed. The phase transformation process has two effects on the material: mechanically, the earlier-formed laths are larger and softer and therefore more ductile (as revealed by nanoindentation); chemically, due to the higher dislocation density inside the later-formed laths, which are generally smaller, carbon Cottrell atmospheres are predominantly observed.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000431469300044 Publication Date 2018-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.714 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.714
Call Number UA @ lucian @ c:irua:151554 Serial 5033
Permanent link to this record
 

 
Author Pourbabak, S.; Montero-Sistiaga, M.L.; Schryvers, D.; Van Humbeeck, J.; Vanmeensel, K.
Title Microscopic investigation of as built and hot isostatic pressed Hastelloy X processed by Selective Laser Melting Type A1 Journal article
Year 2019 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 153 Issue Pages 366-371
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Microstructural characteristics of Hastelloy X produced by Selective Laser Melting have been investigated by various microscopic techniques in the as built (AB) condition and after hot isostatic pressing (HIP). At sub-grain level the AB material consists of columnar high density dislocation cells while the HIP sample consists of columnar sub-grains with lower dislocation density that originate from the original dislocation cells, contradicting existing models. The sub-grains contain nanoscale precipitates enriched in Al, Ti, Cr and O, located at sub-grain boundaries in the AB condition and within the grains after HIP. At some grain boundaries, micrometer sized chromium carbides are detected after HIP. Micro hardness within the grains was found to decrease after HIP, which was attributed to the decrease in dislocation density due to recovery annealing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472696900040 Publication Date 2019-05-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.714 Times cited 2 Open Access Not_Open_Access
Notes S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine and financial support. This work was also made possible through the AUHA13009 grant “TopSPIN for TEM nanostatistics” of the Flemish HERCULES foundation. Approved Most recent IF: 2.714
Call Number EMAT @ emat @UA @ admin @ c:irua:159974 Serial 5178
Permanent link to this record
 

 
Author Boyat, X.; Ballat-Durand, D.; Marteau, J.; Bouvier, S.; Favergeon, J.; Orekhov, A.; Schryvers, D.
Title Interfacial characteristics and cohesion mechanisms of linear friction welded dissimilar titanium alloys: Ti–5Al–2Sn–2Zr–4Mo–4Cr (Ti17) and Ti–6Al–2Sn–4Zr–2Mo (Ti6242) Type A1 Journal article
Year 2019 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 158 Issue Pages 109942
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A detailed microstructural examination endeavoring to understand the interfacial phenomena yielding to cohesion

in solid-state assembling processes was performed. This study focuses on the transition zone of a dissimilar

titanium alloy joint obtained by Linear Friction Welding (LFW) the β-metastable Ti17 to the near-α

Ti6242. The transition zone delimitating both alloys is characterized by a sharp microstructure change from

acicular HCP (Hexagonal Close-Packed) α′ martensitic laths in the Ti6242 to equiaxed BCC β (Body-Centered

Cubic) subgrains in the Ti17; these α′ plates were shown to precipitate within prior-β subgrains remarkably more

rotated than the ones formed in the Ti17. Both α′ and β microstructures were found to be intermingled within

transitional subgrains demarcating a limited gradient from one chemical composition to the other. These peculiar

interfacial grains revealed that the cohesive mechanisms between the rubbing surfaces occurred in the

single-phase β domain under severe strain and high-temperature conditions. During the hot deformation process,

the mutual migration of the crystalline interfaces from one material to another assisted by a continuous dynamic

recrystallization process was identified as the main adhesive mechanism at the junction zone. The latter led to

successful cohesion between the rubbing surfaces. Once the reciprocating motion stopped, fast cooling caused

both materials to experience either a βlean→α′ or βlean→βmetastable transformation in the interfacial zone depending

on their local chemical composition. The limited process time and the subsequent hindered chemical

homogenization at the transition zone led to retaining the so-called intermingled α’/βm subgrains constituting

the border between both Ti-alloys.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000503314000018 Publication Date 2019-10-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.714 Times cited Open Access
Notes The authors gratefully acknowledge the financial support of the French National Research Agency (ANR) through the OPTIMUM ANR- 14-CE27-0017 project. The authors would also like to thank the Hautsde- France Region and the European Regional Development Fund (ERDF) 2014/2020 for the co-funding of this work. The authors would also like to thank ACB for providing LFW samples as well as Airbus for their technical support. Approved Most recent IF: 2.714
Call Number EMAT @ emat @c:irua:165084 Serial 5441
Permanent link to this record
 

 
Author Charalampopoulou, E.; Lambrinou, K.; Van der Donck, T.; Paladino, B.; Di Fonzo, F.; Azina, C.; Eklund, P.; Mraz, S.; Schneider, J.M.; Schryvers, D.; Delville, R.
Title Early stages of dissolution corrosion in 316L and DIN 1.4970 austenitic stainless steels with and without anticorrosion coatings in static liquid lead-bismuth eutectic (LBE) at 500 degrees C Type A1 Journal article
Year 2021 Publication Materials Characterization Abbreviated Journal Mater Charact
Volume 178 Issue Pages 111234
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This work addresses the early stages (<= 1000 h) of the dissolution corrosion behavior of 316L and DIN 1.4970 austenitic stainless steels in contact with oxygen-poor (C-O < 10(-8) mass%), static liquid lead-bismuth eutectic (LBE) at 500 degrees C for 600-1000 h. The objective of this study was to determine the relative early-stage resistance of the uncoated steels to dissolution corrosion and to assess the protectiveness of select candidate coatings (Cr2AlC, Al2O3, V2AlxCy). The simultaneous exposure of steels with intended differences in microstructure and thermomechanical state showed the effects of steel grain size, density of annealing/deformation twins, and secondary precipitates on the steel dissolution corrosion behavior. The findings of this study provide recommendations on steel manufacturing with the aim of using the steels to construct Gen-IV lead-cooled fast reactors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000752582700001 Publication Date 2021-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.714 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.714
Call Number UA @ admin @ c:irua:186509 Serial 7061
Permanent link to this record
 

 
Author Schryvers, D.; Boullay, P.; Potapov, P.L.; Kohn, R.V.; Ball, J.M.
Title Microstructures and interfaces in Ni-Al martensite: comparing HRTEM observations with continuum theories Type A1 Journal article
Year 2002 Publication International journal of solids and structures Abbreviated Journal Int J Solids Struct
Volume 39 Issue Pages 3543-3554
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000176752500014 Publication Date 2002-10-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7683; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.76 Times cited 13 Open Access
Notes Approved Most recent IF: 2.76; 2002 IF: 1.080
Call Number UA @ lucian @ c:irua:48771 Serial 2078
Permanent link to this record
 

 
Author Van Aert, S.; den Dekker, A.J.; van Dyck, D.; van den Bos, A.
Title High-resolution electron microscopy and electron tomography: resolution versus precision Type A1 Journal article
Year 2002 Publication Journal of structural biology Abbreviated Journal J Struct Biol
Volume 138 Issue Pages 21-33
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000177978800003 Publication Date 2002-09-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1047-8477; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.767 Times cited 33 Open Access
Notes Approved Most recent IF: 2.767; 2002 IF: 4.194
Call Number UA @ lucian @ c:irua:47520 Serial 1446
Permanent link to this record
 

 
Author Van Havenbergh, K.; Turner, S.; Driesen, K.; Bridel, J.-S.; Van Tendeloo, G.
Title Solidelectrolyte interphase evolution of carbon-coated silicon nanoparticles for lithium-ion batteries monitored by transmission electron microscopy and impedance spectroscopy Type A1 Journal article
Year 2015 Publication Energy technology Abbreviated Journal Energy Technol-Ger
Volume 3 Issue 3 Pages 699-708
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The main drawbacks of silicon as the most promising anode material for lithium-ion batteries (theoretical capacity=3572 mAh g−1) are lithiation-induced volume changes and the continuous formation of a solidelectrolyte interphase (SEI) upon cycling. A recent strategy is to focus on the influence of coatings and composite materials. To this end, the evolution of the SEI, as well as an applied carbon coating, on nanosilicon electrodes during the first electrochemical cycles is monitored. Two specific techniques are combined: Transmission Electron Microscopy (TEM) is used to study the surface evolution of the nanoparticles on a very local scale, whereas electrochemical impedance spectroscopy (EIS) provides information on the electrode level. A TEMEELS fingerprint signal of carbonate structures from the SEI is discovered, which can be used to differentiate between the SEI and a graphitic carbon matrix. Furthermore, the shielding effect of the carbon coating and the thickness evolution of the SEI are described.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000357869100003 Publication Date 2015-06-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4288; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.789 Times cited Open Access
Notes IWT Flanders Approved Most recent IF: 2.789; 2015 IF: 2.824
Call Number c:irua:126676 Serial 3051
Permanent link to this record
 

 
Author Van Havenbergh, K.; Turner, S.; Marx, N.; Van Tendeloo, G.
Title The mechanical behavior during (de)lithiation of coated silicon nanoparticles as anode material for lithium-ion batteries studied by InSitu transmission electron microscopy Type A1 Journal article
Year 2016 Publication Energy technology Abbreviated Journal Energy Technol-Ger
Volume 4 Issue 4 Pages 1005-1012
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract One approach to cope with the continuous irreversible capacity loss in Si-based electrodes, attributed to lithiation-induced volume changes and the formation of a solid-electrolyte interface (SEI), is by coating silicon nanoparticles. A coating can improve the conductivity of the electrode, form a chemical shield against the electrolyte, or provide mechanical confinement to reduce the volume increase. The influence of such a coating on the mechanical behavior of silicon nanoparticles during Li insertion and Li extraction was investigated by insitu transmission electron microscopy. The type of coating was shown to influence the size of the unreacted core that remains after reaction of silicon with lithium. Furthermore, two mechanisms to relieve the stress generated during volume expansion are reported: the initiation of cracks and the formation of nanovoids. Both result in a full reaction of the silicon nanoparticles, whereas with the formation of cracks, additional surface area is created, on which an SEI can be formed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382549500012 Publication Date 2016-06-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4296; 2194-4288 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.789 Times cited 6 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:137167 Serial 4406
Permanent link to this record
 

 
Author Rehor, I.; Mackova, H.; Filippov, S.K.; Kucka, J.; Proks, V.; Slegerova, J.; Turner, S.; Van Tendeloo, G.; Ledvina, M.; Hruby, M.; Cigler, P.;
Title Fluorescent nanodiamonds with bioorthogonally reactive protein-resistant polymeric coatings Type A1 Journal article
Year 2014 Publication ChemPlusChem Abbreviated Journal Chempluschem
Volume 79 Issue 1 Pages 21-24
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The novel synthesis of a polymeric interface grown from the surface of bright fluorescent nanodiamonds is reported. The polymer enables bioorthogonal attachment of various molecules by click chemistry; the particles are resistant to nonspecific protein adsorption and show outstanding colloidal stability in buffers and biological media. The coating fully preserves the unique optical properties of the nitrogen-vacancy centers that are crucial for bioimaging and sensoric applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000337974900002 Publication Date 2013-12-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2192-6506; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.797 Times cited 34 Open Access
Notes EU 7FP Program (no.262348); European Soft Matter Infrastructure; ESMI; ERC (grant no.246791)-COUNTATOMS; FWO Approved Most recent IF: 2.797; 2014 IF: 2.997
Call Number UA @ lucian @ c:irua:113088 Serial 1235
Permanent link to this record
 

 
Author Corthals, S.; van Noyen, J.; Liang, D.; Ke, X.; Van Tendeloo, G.; Jacobs, P.; Sels, B.
Title A cyclic catalyst pretreatment in CO2 for high yield production of Carbon nanofibers with narrow diameter distribution Type A1 Journal article
Year 2011 Publication Catalysis letters Abbreviated Journal Catal Lett
Volume 141 Issue 11 Pages 1621-1624
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This paper presents a cyclic catalyst pretreatment process to improve the CNF yield with narrow size distribution by sequentially feeding the CVD reactor with CH4/CO2 mixtures (carbon deposition) and CO2 (carbon removal) prior to the actual growth process. A mechanism based on a break-up of large Ni particles tentatively explains the beneficial effect of the cyclic carbon deposition/removal CVD procedure.
Address
Corporate Author Thesis
Publisher Place of Publication Basel Editor
Language Wos 000296471400006 Publication Date 2011-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1011-372X;1572-879X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.799 Times cited 1 Open Access
Notes Iwt; Iap Approved Most recent IF: 2.799; 2011 IF: 2.242
Call Number UA @ lucian @ c:irua:91888 Serial 598
Permanent link to this record
 

 
Author Wang, J.; Nguyen, M.D.; Gauquelin, N.; Verbeeck, J.; Do, M.T.; Koster, G.; Rijnders, G.; Houwman, E.
Title On the importance of the work function and electron carrier density of oxide electrodes for the functional properties of ferroelectric capacitors Type A1 Journal article
Year 2020 Publication Physica Status Solidi-Rapid Research Letters Abbreviated Journal Phys Status Solidi-R
Volume 14 Issue 14 Pages 1900520
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract It is important to understand the effect of the interfaces between the oxide electrode layers and the ferroelectric layer on the polarization response for optimizing the device performance of all-oxide ferroelectric devices. Herein, the effects of the oxide La0.07Ba0.93SnO3 (LBSO) as an electrode material in an PbZr0.52Ti0.48O3 (PZT) ferroelectric capacitor are compared with those of the more commonly used SrRuO3 (SRO) electrode. SRO (top)/PZT/SRO (bottom), SRO/PZT/LBSO, and SRO/PZT/2 nm SRO/LBSO devices are fabricated. Only marginal differences in crystalline properties, determined by X-ray diffraction and scanning transmission electron microscopy, are found. High-quality polarization loops are obtained, but with a much larger coercive field for the SRO/PZT/LBSO device. In contrast to the SRO/PZT/SRO device, the polarization decreases strongly with increasing field cycling. This fatigue problem can be remedied by inserting a 2 nm SRO layer between PZT and LBSO. It is argued that strongly increased charge injection into the PZT occurs at the bottom interface, because of the low PZT/LBSO interfacial barrier and the much lower carrier density in LBSO, as compared with that in SRO, causing a low dielectric constant, depleted layer in LBSO. The charge injection creates a trapped space charge in the PZT, causing the difference in fatigue behavior.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000506195600001 Publication Date 2019-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6254 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 6 Open Access OpenAccess
Notes ; This work was supported by Nederlandse Organisatie voor Wetenschappelijk Onderzoek through grant no.13HTSM01. ; Approved Most recent IF: 2.8; 2020 IF: 3.032
Call Number UA @ admin @ c:irua:165681 Serial 6316
Permanent link to this record
 

 
Author Nord, M.; Webster, R.W.H.; Paton, K.A.; McVitie, S.; McGrouther, D.; MacLaren, I.; Paterson, G.W.
Title Fast pixelated detectors in scanning transmission electron microscopy. Part I: data acquisition, live processing, and storage Type A1 Journal article
Year 2020 Publication Microscopy And Microanalysis Abbreviated Journal Microsc Microanal
Volume 26 Issue 4 Pages Pii S1431927620001713-666
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The use of fast pixelated detectors and direct electron detection technology is revolutionizing many aspects of scanning transmission electron microscopy (STEM). The widespread adoption of these new technologies is impeded by the technical challenges associated with them. These include issues related to hardware control, and the acquisition, real-time processing and visualization, and storage of data from such detectors. We discuss these problems and present software solutions for them, with a view to making the benefits of new detectors in the context of STEM more accessible. Throughout, we provide examples of the application of the technologies presented, using data from a Medipix3 direct electron detector. Most of our software are available under an open source licence, permitting transparency of the implemented algorithms, and allowing the community to freely use and further improve upon them.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000555537900004 Publication Date 2020-07-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 4 Open Access OpenAccess
Notes ; The performance of this work was mainly supported by the Engineering and Physical Sciences Research Council (EPSRC) of the UK via the project “Fast Pixel Detectors: a paradigm shift in STEM imaging” (grant no. EP/M009963/1). G.W.P. received additional support from the EPSRC under grant no. EP/M024423/1. M.N. received additional support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 838001. The studentship of R.W.H.W. was supported by the EPSRC Doctoral Training Partnership grant no. EP/N509668/1. S.McV. was supported by EPSRC grant no. EP/M024423/1. I.M. was supported by EPSRC grant no. EP/M009963/1. The studentship of K.A.P. was funded entirely by the UK Science and Technology Facilities Council (STFC) Industrial CASE studentship “Next2 TEM Detection” (no. ST/P002471/1) with Quantum Detectors Ltd. as the industrial partner. D.McG. was also supported by EPSRC grant no. EP/M009963/1. As an inventor of intellectual property related to the MERLIN detector hardware, he is a beneficiary of the license agreement between the University of Glasgow and Quantum Detectors Ltd. The development of the integration of TopSpin with the Merlin readout of the Medipix3 camera has been performed with the aid of financial assistance from the EPSRC under grant no. EP/R511705/1 and through direct collaboration between NanoMEGAS and Quantum Detectors Ltd. ; Approved Most recent IF: 2.8; 2020 IF: 1.891
Call Number UA @ admin @ c:irua:171185 Serial 6518
Permanent link to this record
 

 
Author Paterson, G.W.; Webster, R.W.H.; Ross, A.; Paton, K.A.; Macgregor, T.A.; McGrouther, D.; MacLaren, I.; Nord, M.
Title Fast pixelated detectors in scanning transmission electron microscopy. part II : post-acquisition data processing, visualization, and structural characterization Type A1 Journal article
Year 2020 Publication Microscopy And Microanalysis Abbreviated Journal Microsc Microanal
Volume 26 Issue 5 Pages 944-963
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Fast pixelated detectors incorporating direct electron detection (DED) technology are increasingly being regarded as universal detectors for scanning transmission electron microscopy (STEM), capable of imaging under multiple modes of operation. However, several issues remain around the post-acquisition processing and visualization of the often very large multidimensional STEM datasets produced by them. We discuss these issues and present open source software libraries to enable efficient processing and visualization of such datasets. Throughout, we provide examples of the analysis methodologies presented, utilizing data from a 256 x 256 pixel Medipix3 hybrid DED detector, with a particular focus on the STEM characterization of the structural properties of materials. These include the techniques of virtual detector imaging; higher-order Laue zone analysis; nanobeam electron diffraction; and scanning precession electron diffraction. In the latter, we demonstrate a nanoscale lattice parameter mapping with a fractional precision <= 6 x 10(-4) (0.06%).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000576859800011 Publication Date 2020-09-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 3 Open Access OpenAccess
Notes ; G.W.P. and M.N. were the principal authors of the fpd and pixStem libraries reported herein (details of all contributions are documented in the repositories) and have made all of these available under open source licence GPLv3 for the benefit of the community. R.W.H.W., A.R., and K.A.P. have also made contributions to the source codes in these libraries. G.W.P and M.N. have led the data acquisition and analysis, and the drafting of this manuscript. The performance of this work was mainly supported by Engineering and Physical Sciences Research Council (EPSRC) of the UK via the project “Fast Pixel Detectors: a paradigm shift in STEM imaging” (Grant No. EP/M009963/1). G.W.P. received additional support from the EPSRC under Grant No. EP/M024423/1. M.N. received additional support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 838001. R.W.H.W., A.R., K.A.P., T.A.M., D.McG., and I.M. have all contributed either through acquisition and analysis of data or through participation in the revision of the manuscript. The studentships of R.W.H.W. and T.A.M. were supported by the EPSRC Doctoral Training Partnership Grant No. EP/N509668/1. I.M. and D.McG. were supported by EPSRC Grant No. EP/M009963/1. The studentship of K.A.P. was funded entirely by the UK Science and Technology Facilities Council (STFC) Industrial CASE studentship “Next2 TEM Detection” (No. ST/ P002471/1) with Quantum Detectors Ltd. as the industrial partner. As an inventor of intellectual property related to the MERLIN detector hardware, D.McG. is a beneficiary of the license agreement between the University of Glasgow and Quantum Detectors Ltd. We thank Diamond Quantum Detectors Ltd. for Medipix3 detector support; Dr. Bruno Humbel from Okinawa Institute of Science and Technology; and Dr. Caroline Kizilyaprak from the University of Lausanne for providing the liver sample; Dr. Ingrid Hallsteinsen and Prof. Thomas Tybell from the Norwegian University of Science and Technology (NTNU) for providing the La0.7Sr0.3MnO3/LaFeO3/SrTiO3 sample shown in Figure 4; and NanoMEGAS for the loan of the DigiSTAR precession system and TopSpin acquisition software. The development of the integration of TopSpin with the Merlin readout of the Medipix3 camera has been performed with the aid of financial assistance from the EPSRC under Grant No. EP/R511705/1 and through direct collaboration between NanoMEGAS and Quantum Detectors Ltd. ; Approved Most recent IF: 2.8; 2020 IF: 1.891
Call Number UA @ admin @ c:irua:172695 Serial 6519
Permanent link to this record
 

 
Author Ning, S.; Xu, W.; Ma, Y.; Loh, L.; Pennycook, T.J.; Zhou, W.; Zhang, F.; Bosman, M.; Pennycook, S.J.; He, Q.; Loh, N.D.
Title Accurate and Robust Calibration of the Uniform Affine Transformation Between Scan-Camera Coordinates for Atom-Resolved In-Focus 4D-STEM Datasets Type A1 Journal article
Year 2022 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume Issue Pages 1-11
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Accurate geometrical calibration between the scan coordinates and the camera coordinates is critical in four-dimensional scanning transmission electron microscopy (4D-STEM) for both quantitative imaging and ptychographic reconstructions. For atomic-resolved, in-focus 4D-STEM datasets, we propose a hybrid method incorporating two sub-routines, namely a J-matrix method and a Fourier method, which can calibrate the uniform affine transformation between the scan-camera coordinates using raw data, without a priori knowledge about the crystal structure of the specimen. The hybrid method is found robust against scan distortions and residual probe aberrations. It is also effective even when defects are present in the specimen, or the specimen becomes relatively thick. We will demonstrate that a successful geometrical calibration with the hybrid method will lead to a more reliable recovery of both the specimen and the electron probe in a ptychographic reconstruction. We will also show that, although the elimination of local scan position errors still requires an iterative approach, the rate of convergence can be improved, and the residual errors can be further reduced if the hybrid method can be firstly applied for initial calibration. The code is made available as a simple-to-use tool to correct affine transformations of the scan-camera coordinates in 4D-STEM experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000767045700001 Publication Date 2022-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited Open Access OpenAccess
Notes N. D. Loh kindly acknowledges support from NUS Early Career Research Award (R-154-000-B35-133), MOE’s AcRF Tier 1 grant nr. R-284-000-172-114 and NRF CRP grant number NRF-CRP16-2015-05. Q. He would also like to acknowledge the support of the National Research Foundation (NRF) Singapore, under its NRF Fellowship (NRF-NRFF11-2019-0002). W. Zhou acknowledges the support from Beijing Outstanding Young Scientist Program (BJJWZYJH01201914430039). F. Zhang acknowledges the support of the National Natural Science Foundation of China (11775105, 12074167). T. J. Pennycook acknowledges funding under the European Union’s Horizon 2020 research and innovation programme from the European Research Council (ERC) Grant agreement No. 802123-HDEM. Approved Most recent IF: 2.8
Call Number EMAT @ emat @c:irua:186958 Serial 6957
Permanent link to this record
 

 
Author Yu, C.-P.; Friedrich, T.; Jannis, D.; Van Aert, S.; Verbeeck, J.
Title Real-Time Integration Center of Mass (riCOM) Reconstruction for 4D STEM Type A1 Journal article
Year 2022 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume Issue Pages 1-12
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A real-time image reconstruction method for scanning transmission electron microscopy (STEM) is proposed. With an algorithm requiring only the center of mass of the diffraction pattern at one probe position at a time, it is able to update the resulting image each time a new probe position is visited without storing any intermediate diffraction patterns. The results show clear features at high spatial frequency, such as atomic column positions. It is also demonstrated that some common post-processing methods, such as band-pass filtering, can be directly integrated in the real-time processing flow. Compared with other reconstruction methods, the proposed method produces high-quality reconstructions with good noise robustness at extremely low memory and computational requirements. An efficient, interactive open source implementation of the concept is further presented, which is compatible with frame-based, as well as event-based camera/file types. This method provides the attractive feature of immediate feedback that microscope operators have become used to, for example, conventional high-angle annular dark field STEM imaging, allowing for rapid decision-making and fine-tuning to obtain the best possible images for beam-sensitive samples at the lowest possible dose.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000792176100001 Publication Date 2022-04-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 7 Open Access OpenAccess
Notes Bijzonder Onderzoeksfonds UGent; H2020 European Research Council, 770887 ; H2020 European Research Council, 823717 ; H2020 European Research Council, ESTEEM3 / 823717 ; H2020 European Research Council, PICOMETRICS / 770887 ; Fonds Wetenschappelijk Onderzoek, 30489208 ; Herculesstichting; esteem3reported; esteem3jra Approved Most recent IF: 2.8
Call Number EMAT @ emat @c:irua:188538 Serial 7068
Permanent link to this record
 

 
Author De wael, A.; De Backer, A.; Yu, C.-P.; Sentürk, D.G.; Lobato, I.; Faes, C.; Van Aert, S.
Title Three Approaches for Representing the Statistical Uncertainty on Atom-Counting Results in Quantitative ADF STEM Type A1 Journal article
Year 2022 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume Issue Pages 1-9
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A decade ago, a statistics-based method was introduced to count the number of atoms from annular dark-field scanning transmission electron microscopy (ADF STEM) images. In the past years, this method was successfully applied to nanocrystals of arbitrary shape, size, and composition (and its high accuracy and precision has been demonstrated). However, the counting results obtained from this statistical framework are so far presented without a visualization of the actual uncertainty about this estimate. In this paper, we present three approaches that can be used to represent counting results together with their statistical error, and discuss which approach is most suited for further use based on simulations and an experimental ADF STEM image.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000854930500001 Publication Date 2022-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record
Impact Factor (up) 2.8 Times cited Open Access OpenAccess
Notes This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp. The authors are grateful to L.M. Liz-Marzán (CIC biomaGUNE and Ikerbasque) for providing the samples. esteem3reported; esteem3jra Approved Most recent IF: 2.8
Call Number EMAT @ emat @c:irua:190585 Serial 7119
Permanent link to this record
 

 
Author Vega Ibañez, F.; Béché, A.; Verbeeck, J.
Title Can a programmable phase plate serve as an aberration corrector in the transmission electron microscope (TEM)? Type A1 Journal article
Year 2022 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume Issue Pages Pii S1431927622012260-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Current progress in programmable electrostatic phase plates raises questions about their usefulness for specific applications. Here, we explore different designs for such phase plates with the specific goal of correcting spherical aberration in the transmission electron microscope (TEM). We numerically investigate whether a phase plate could provide down to 1 angstrom ngstrom spatial resolution on a conventional uncorrected TEM. Different design aspects (fill factor, pixel pattern, symmetry) were evaluated to understand their effect on the electron probe size and current density. Some proposed designs show a probe size () down to 0.66 angstrom, proving that it should be possible to correct spherical aberration well past the 1 angstrom limit using a programmable phase plate consisting of an array of electrostatic phase-shifting elements.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000849975400001 Publication Date 2022-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 3 Open Access OpenAccess
Notes All authors acknowledge funding from the Flemish Research Fund under contract G042820N “Exploring adaptive optics in transmission electron microscopy”. J.V. acknowledges funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3 and from the University of Antwerp through a TOP BOF project.; esteem3reported; esteem3jra Approved Most recent IF: 2.8
Call Number UA @ admin @ c:irua:190627 Serial 7134
Permanent link to this record
 

 
Author Friedrich, T.; Yu, C.-P.; Verbeeck, J.; Van Aert, S.
Title Phase object reconstruction for 4D-STEM using deep learning Type A1 Journal article
Year 2023 Publication Microscopy and microanalysis Abbreviated Journal
Volume 29 Issue 1 Pages 395-407
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this study, we explore the possibility to use deep learning for the reconstruction of phase images from 4D scanning transmission electron microscopy (4D-STEM) data. The process can be divided into two main steps. First, the complex electron wave function is recovered for a convergent beam electron diffraction pattern (CBED) using a convolutional neural network (CNN). Subsequently, a corresponding patch of the phase object is recovered using the phase object approximation. Repeating this for each scan position in a 4D-STEM dataset and combining the patches by complex summation yields the full-phase object. Each patch is recovered from a kernel of 3x3 adjacent CBEDs only, which eliminates common, large memory requirements and enables live processing during an experiment. The machine learning pipeline, data generation, and the reconstruction algorithm are presented. We demonstrate that the CNN can retrieve phase information beyond the aperture angle, enabling super-resolution imaging. The image contrast formation is evaluated showing a dependence on the thickness and atomic column type. Columns containing light and heavy elements can be imaged simultaneously and are distinguishable. The combination of super-resolution, good noise robustness, and intuitive image contrast characteristics makes the approach unique among live imaging methods in 4D-STEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001033590800038 Publication Date 2023-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.8 Times cited 1 Open Access OpenAccess
Notes We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no. 770887 PICOMETRICS) and funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 823717 ESTEEM3. J.V. and S.V.A acknowledge funding from the University of Antwerp through a TOP BOF project. The direct electron detector (Merlin, Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. This work was supported by the FWO and FNRS within the 2Dto3D project of the EOS program (grant number 30489208). Approved Most recent IF: 2.8; 2023 IF: 1.891
Call Number UA @ admin @ c:irua:198221 Serial 8912
Permanent link to this record
 

 
Author Gholam, S.; Denisov, N.; Orekhov, A.; Verbeeck, J.; Hadermann, J.
Title An Investigation on 3D Electron Diffraction and 4-Dimensional Scanning Diffraction Tomography Using a Scanning Electron Microscope Type P1 Conference Proceedings
Year 2024 Publication Microscopy and Microanalysis Abbreviated Journal
Volume 30 Issue Supplement_1 Pages
Keywords P1 Conference Proceedings; Electron Microscopy for Materials Science (EMAT) ;
Abstract During the last decade, 3D-Electron Diffraction (3D-ED) has emerged as a powerful technique for studying the structure of sub-micron particles. It is used in a variety of applications, from unit cell and space group determination to the complete solution of the structure similar to X-ray diffraction techniques. So far, this technique has been only implemented in Transmission Electron Microscopes (TEMs). Performing such an experiment in a Scanning Electron Microscope (SEM) can be challenging, mainly due to the lower acceleration voltage. This lower beam energy raises concerns about severe multiple scattering and limited transmissivity of the sample for the weakly accelerated electrons.

In this work, we show the possibilities of operating similar studies in a modified SEM. For this aim, we equipped our SEM with a custom stage and holder, a direct electron detector and a custom high-angle annular dark-field detector (HAADF). A range of samples was studied in the form of lamellas and sub-micron particles, and the quality of the diffraction data was evaluated for different purposes, such as unit cell determination and space group determination. Moreover, the ability to integrate the diffraction data for structure solution and refinement has been assessed and compared to similar data acquired in a TEM.

Finally, we also demonstrate the potential for combining diffraction tomography and 4-dimensional scanning transmission electron microscopy (4D-STEM) in our setup. This method opens an avenue to obtain multiple 3DED datasets out of 5D-STEM data. These 3DED datasets can be created using object tracking methods from several regions of a multi-domain particle or from multiple single crystals within the scanning region. This provides an attractive route to high-throughput and statistically relevant characterization of polycrystalline materials or powders of nanoparticles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links
Impact Factor (up) 2.8 Times cited Open Access
Notes The authors acknowledge the financial support of the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. The authors are also grateful to Amsterdam Scientific Instruments. Approved Most recent IF: 2.8; 2024 IF: 1.891
Call Number EMAT @ emat @ Serial 9269
Permanent link to this record
 

 
Author Stoops, T.; De Backer, A.; Lobato, I.; Van Aert, S.
Title Obtaining 3D Atomic Reconstructions from Electron Microscopy Images Using a Bayesian Genetic Algorithm: Possibilities, Insights, and Limitations Type A1 Journal Article
Year 2024 Publication Microscopy and Microanalysis Abbreviated Journal
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The Bayesian genetic algorithm (BGA) is a powerful tool to reconstruct the 3D structure of mono-atomic single-crystalline metallic nanoparticles imaged using annular dark field scanning transmission electron microscopy. The number of atoms in a projected atomic column in the image is used as input to obtain an accurate and atomically precise reconstruction of the nanoparticle, taking prior knowledge and the finite precision of atom counting into account. However, as the number of parameters required to describe a nanoparticle with atomic detail rises quickly with the size of the studied particle, the computational costs of the BGA rise to prohibitively expensive levels. In this study, we investigate these computational costs and propose methods and control parameters for efficient application of the algorithm to nanoparticles of at least up to 10 nm in size.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-10-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links
Impact Factor (up) 2.8 Times cited Open Access
Notes European Research Council, 770887 ; Research Foundation Flanders, G034621N G0A7723N 40007495 ; FWO and F.R.S-FNRS; Flemish Government; Approved Most recent IF: 2.8; 2024 IF: 1.891
Call Number EMAT @ emat @ Serial 9270
Permanent link to this record
 

 
Author van Oeffelen, L.; Van Roy, W.; Idrissi, H.; Charlier, D.; Lagae, L.; Borghs, G.
Title Ion current rectification, limiting and overlimiting conductances in nanopores Type A1 Journal article
Year 2015 Publication PLoS ONE Abbreviated Journal Plos One
Volume 10 Issue 10 Pages e0124171
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Previous reports on Poisson-Nernst-Planck (PNP) simulations of solid-state nanopores have focused on steady state behaviour under simplified boundary conditions. These are Neumann boundary conditions for the voltage at the pore walls, and in some cases also Donnan equilibrium boundary conditions for concentrations and voltages at both entrances of the nanopore. In this paper, we report time-dependent and steady state PNP simulations under less restrictive boundary conditions, including Neumann boundary conditions applied throughout the membrane relatively far away from the nanopore. We simulated ion currents through cylindrical and conical nanopores with several surface charge configurations, studying the spatial and temporal dependence of the currents contributed by each ion species. This revealed that, due to slow co-diffusion of oppositely charged ions, steady state is generally not reached in simulations or in practice. Furthermore, it is shown that ion concentration polarization is responsible for the observed limiting conductances and ion current rectification in nanopores with asymmetric surface charges or shapes. Hence, after more than a decade of collective research attempting to understand the nature of ion current rectification in solid-state nanopores, a relatively intuitive model is retrieved. Moreover, we measured and simulated current-voltage characteristics of rectifying silicon nitride nanopores presenting overlimiting conductances. The similarity between measurement and simulation shows that overlimiting conductances can result from the increased conductance of the electric double-layer at the membrane surface at the depletion side due to voltage-induced polarization charges.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000354916100012 Publication Date 2015-05-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.806 Times cited 11 Open Access
Notes Approved Most recent IF: 2.806; 2015 IF: 3.234
Call Number c:irua:126366 Serial 1744
Permanent link to this record
 

 
Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Antipov, E.V.
Title Chemistry and structure of anion-deficient perovskites with translational interfaces Type A1 Journal article
Year 2008 Publication Journal of the American Ceramic Society Abbreviated Journal J Am Ceram Soc
Volume 91 Issue 6 Pages 1807-1813
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Columbus, Ohio Editor
Language Wos 000256410700010 Publication Date 2008-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7820;1551-2916; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.841 Times cited 39 Open Access
Notes Approved Most recent IF: 2.841; 2008 IF: 2.101
Call Number UA @ lucian @ c:irua:70088 Serial 355
Permanent link to this record
 

 
Author Fang, P.a.; Gu, H.; Wang, P.l.; Van Landuyt, J.; Vleugels, J.; Van der Biest, O.;
Title Effect of powder coating on stabilizer distribution in CeO2-stabilized ZrO2 ceramics Type A1 Journal article
Year 2005 Publication Journal of the American Ceramic Society Abbreviated Journal J Am Ceram Soc
Volume 88 Issue 7 Pages 1929-1934
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The phase and microstructure relationship of 12 mol% CeO2-stabilized ZrO2 ceramics prepared from coated powder was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersed Xray spectroscopy (EDS). As compared with the sample prepared with co-precipitated method, which exhibited a similar grain size distribution, the EDS analysis revealed that the powder coating induced a wide distribution of CeO2 solubility, which decreases monotonically with the increase of grain size. This variation of stabilizer content from grain to grain rendered many large grains in the monoclinic phase. Stronger cerium segregation to grain boundaries was observed between large grains, which often form thin amorphous films there. The inhomogeneous; CeO2 distribution keeps more tetragonal ZrO2 grains close to the phase boundary to facilitate the transforming toughness. Addition of an Al2O3 precursor in coated powders effectively raises the overall CeO2 stabilizer content in the grains and preserves more transformable tetragonal phase in the microstructure, which further enhanced the fracture toughness. The dependence of CeO2 solubility on grain size may be explained in a simple coating-controlled diffusion and growth process that deserves further investigation.
Address
Corporate Author Thesis
Publisher Place of Publication Columbus, Ohio Editor
Language Wos 000230128100040 Publication Date 2005-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7820;1551-2916; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.841 Times cited 11 Open Access
Notes Approved Most recent IF: 2.841; 2005 IF: 1.586
Call Number UA @ lucian @ c:irua:103156 Serial 830
Permanent link to this record
 

 
Author Bals, S.; Verbeeck, J.; Van Tendeloo, G.; Liu, Y.-L.; Grivel, J.-C.
Title Quantitative electron microscopy of (Bi,Pb)2Sr2Ca2Cu3O10+\delta/Ag multifilament tapes during initial stages of annealing Type A1 Journal article
Year 2005 Publication Journal of the American Ceramic Society Abbreviated Journal J Am Ceram Soc
Volume 88 Issue 2 Pages 431-436
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The microstructural and compositional evolution during initial annealing of a superconducting (Bi,Pb)(2)Sr2Ca2Cu3O10+delta/Ag tape is studied using quantitative transmission electron microscopy. Special attention is devoted to the occurrence of Pb-rich liquids, which are crucial for the Bi2Sr2CaCu2O8+delta to (Bi,Pb)(2)Sr2Ca2Cu3O10+delta transformation. Ca and/or Pb-rich (Bi,Pb)(2)Sr2CaCu2O8+delta grains dissolve into a liquid, which reacts with Ca-rich phases to increase the liquid's Ca-content. This leads to (Bi,Pb)(2)Sr2Ca2Cu3O10+delta formation. Apparently, a Ca/Sr ratio of around I is sufficient to keep (Bi,Pb)(2)Sr2Ca2Cu3O10+delta nucleation going. It is confirmed that Ag particles are transported from the Ag-sheath into the oxide core by the liquid and not by mechanical treatment of the tape.
Address
Corporate Author Thesis
Publisher Place of Publication Columbus, Ohio Editor
Language Wos 000227510200030 Publication Date 2005-02-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7820;1551-2916; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (up) 2.841 Times cited 1 Open Access
Notes Approved Most recent IF: 2.841; 2005 IF: 1.586
Call Number UA @ lucian @ c:irua:54876UA @ admin @ c:irua:54876 Serial 2754
Permanent link to this record
 

 
Author Batenburg, K.J.; Bals, S.; Sijbers, J.; Kübel, C.; Midgley, P.A.; Hernandez, J.C.; Kaiser, U.; Encina, E.R.; Coronado, E.A.; Van Tendeloo, G.
Title 3D imaging of nanomaterials by discrete tomography Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue 6 Pages 730-740
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract The field of discrete tomography focuses on the reconstruction of samples that consist of only a few different materials. Ideally, a three-dimensional (3D) reconstruction of such a sample should contain only one grey level for each of the compositions in the sample. By exploiting this property in the reconstruction algorithm, either the quality of the reconstruction can be improved significantly, or the number of required projection images can be reduced. The discrete reconstruction typically contains fewer artifacts and does not have to be segmented, as it already contains one grey level for each composition. Recently, a new algorithm, called discrete algebraic reconstruction technique (DART), has been proposed that can be used effectively on experimental electron tomography datasets. In this paper, we propose discrete tomography as a general reconstruction method for electron tomography in materials science. We describe the basic principles of DART and show that it can be applied successfully to three different types of samples, consisting of embedded ErSi2 nanocrystals, a carbon nanotube grown from a catalyst particle and a single gold nanoparticle, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000265816400005 Publication Date 2009-02-01
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 (up) 2.843 Times cited 220 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:74665 c:irua:74665 Serial 12
Permanent link to this record
 

 
Author Bertoni, G.; Verbeeck, J.
Title Accuracy and precision in model based EELS quantification Type A1 Journal article
Year 2008 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 108 Issue 8 Pages 782-790
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We present results on model based quantification of electron energy loss spectra (EELS), focusing on the factors that influence accuracy and precision in determining chemical concentrations. Several sources of systematical errors are investigated. The spectrometer entrance aperture determines the collection angle, and the effects of its position with respect to the transmitted beam are investigated, taking into account the diffraction by the crystal structure. The effect of the orientation of the sample is tested experimentally and theoretically on SrTiO3, and finally, a simulated experiment on c-BN at different thicknesses confirms the superior results of the model based method with respect to the conventional method. A test on a set of experimental reference compounds is presented, showing that remarkably good accuracy can be obtained. Recommendations are given to achieve high accuracy and precision in practice. (C) 2008 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000258241900010 Publication Date 2008-02-22
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 (up) 2.843 Times cited 44 Open Access
Notes Approved Most recent IF: 2.843; 2008 IF: 2.629
Call Number UA @ lucian @ c:irua:70550UA @ admin @ c:irua:70550 Serial 42
Permanent link to this record
 

 
Author Roelandts, T.; Batenburg, K.J.; Biermans, E.; Kübel, C.; Bals, S.; Sijbers, J.
Title Accurate segmentation of dense nanoparticles by partially discrete electron tomography Type A1 Journal article
Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 114 Issue Pages 96-105
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Accurate segmentation of nanoparticles within various matrix materials is a difficult problem in electron tomography. Due to artifacts related to image series acquisition and reconstruction, global thresholding of reconstructions computed by established algorithms, such as weighted backprojection or SIRT, may result in unreliable and subjective segmentations. In this paper, we introduce the Partially Discrete Algebraic Reconstruction Technique (PDART) for computing accurate segmentations of dense nanoparticles of constant composition. The particles are segmented directly by the reconstruction algorithm, while the surrounding regions are reconstructed using continuously varying gray levels. As no properties are assumed for the other compositions of the sample, the technique can be applied to any sample where dense nanoparticles must be segmented, regardless of the surrounding compositions. For both experimental and simulated data, it is shown that PDART yields significantly more accurate segmentations than those obtained by optimal global thresholding of the SIRT reconstruction.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000301954300011 Publication Date 2012-01-06
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 (up) 2.843 Times cited 34 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2012 IF: 2.470
Call Number UA @ lucian @ c:irua:97710 Serial 52
Permanent link to this record
 

 
Author van den Broek, W.; Verbeeck, J.; de Backer, S.; Scheunders, P.; Schryvers, D.
Title Acquisition of the EELS data cube by tomographic reconstruction Type A1 Journal article
Year 2006 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 106 Issue 4/5 Pages 269-276
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Energy filtered TEM, EFTEM, provides three-dimensional data, two spatial and one spectral dimension. We propose to acquire these data by measuring a series of images with a defocused energy filter. It will be shown that each image is a projection of the data on the detector and that reconstruction of the data out of a sufficient number of such projections using a tomographic reconstruction algorithm is possible. This technique uses only a fraction of the electron dose an energy filtered series (EFS) needs for the same spectral and spatial resolution and the same mean signal-to-noise ratio. (c) 2005 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000236042300003 Publication Date 2005-11-30
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 (up) 2.843 Times cited 6 Open Access
Notes Approved Most recent IF: 2.843; 2006 IF: 1.706
Call Number UA @ lucian @ c:irua:56910UA @ admin @ c:irua:56910 Serial 55
Permanent link to this record
 

 
Author Goris, B.; Roelandts, T.; Batenburg, K.J.; Heidari Mezerji, H.; Bals, S.
Title Advanced reconstruction algorithms for electron tomography : from comparison to combination Type A1 Journal article
Year 2013 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 127 Issue Pages 40-47
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract In this work, the simultaneous iterative reconstruction technique (SIRT), the total variation minimization (TVM) reconstruction technique and the discrete algebraic reconstruction technique (DART) for electron tomography are compared and the advantages and disadvantages are discussed. Furthermore, we describe how the result of a three dimensional (3D) reconstruction based on TVM can provide objective information that is needed as the input for a DART reconstruction. This approach results in a tomographic reconstruction of which the segmentation is carried out in an objective manner.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000316659100007 Publication Date 2012-08-02
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 (up) 2.843 Times cited 63 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2013 IF: 2.745
Call Number UA @ lucian @ c:irua:101217 Serial 72
Permanent link to this record