|   | 
Details
   web
Records
Author (down) Volkov, V.V.; Van Tendeloo, G.; Vargaftik, M.N.; Moiseev, I.I.
Title High-resolution electron microscopy observations of large Pd clusters Type A1 Journal article
Year 1993 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth
Volume 132 Issue Pages 359-363
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1993MA03200001 Publication Date 2002-10-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.698 Times cited 7 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:6839 Serial 1452
Permanent link to this record
 

 
Author (down) Volkov, V.V.; Van Tendeloo, G.; van Landuyt, J.; Amelinckx, S.; Busheva, E.E.; Shabunina, G.G.; Aminov, T.G.; Novotortsev, V.M.
Title HREM image analysis up to structure determination of SbCrSe3: a new 1D ferromagnet Type A1 Journal article
Year 1997 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 132 Issue Pages 257-266
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos A1997YE01700005 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 1 Open Access
Notes Approved Most recent IF: 2.299; 1997 IF: 1.486
Call Number UA @ lucian @ c:irua:21421 Serial 1500
Permanent link to this record
 

 
Author (down) Volkov, V.V.; Van Tendeloo, G.; Tsirkov, G.A.; Cherkashina, N.V.; Vargaftik, M.N.; Moiseev, I.I.; Novotortsev, V.M.; Kvit, A.V.; Chuvilin, A.L.
Title Long- and short-distance ordering of the metal cores of giant Pd clusters Type A1 Journal article
Year 1996 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth
Volume 163 Issue Pages 377-387
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1996UW51100006 Publication Date 2003-04-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.698 Times cited 28 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:16866 Serial 1834
Permanent link to this record
 

 
Author (down) Volkov, V.V.; van Landuyt, J.; Marushkin, K.M.; Gijbels, R.; Férauge, C.; Vasilyev, M.G.; Shelyakin, A.A.; Sokolovsky, A.A.
Title Characterization of LPE grown InGaAsP/InP heterostructures: IR-LED at 1.66 μm used for the remote monitoring of methane gas Type A1 Journal article
Year 1997 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth
Volume 173 Issue Pages 285-296
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1997XC98100008 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0248 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.751 Times cited 4 Open Access
Notes Approved Most recent IF: 1.751; 1997 IF: 1.259
Call Number UA @ lucian @ c:irua:20459 Serial 324
Permanent link to this record
 

 
Author (down) Volkov, V.V.; van Landuyt, J.; Marushkin, K.; Gijbels, R.; Férauge, C.; Vasilyev, M.G.; Shelyakin, A.A.; Sokolovsky, A.A.
Title LPE growth and characterization of InGaAsP/InP heterostructures: IR-emitting diodes at 1.66 μm: application to the remote monitoring of methane gas Type A1 Journal article
Year 1997 Publication Sensors and actuators : A : physical Abbreviated Journal Sensor Actuat A-Phys
Volume 62 Issue 1/3 Pages 624-632
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Highly effective IR light-emitting diodes operating at the wavelength 1.66 mu m and based on the buried heterostructure In0.88Ga0.12As0.26P0.74/ In0.72Ga0.28As0.62P0.38/In0.53Ga0.47As/InP have been grown by liquid-phase epitaxy (LPE) and characterized in detail by means of transmission electron microscopy (TEM), high-resolution electron microscopy (HREM),electron diffraction (ED), X-ray diffraction (XRD), secondary-ion mass spectrometry (SIMS) and electroluminescence measurements. The InGaAsP epilayers are found to be well lattice matched and of good structural quality. A tentative explanation is presented for the spinodal decomposition observed in InGaAsP alloys. A new type of selective CK, gas sensor has been developed and fabricated an the basis of the IR light-emitting diode mentioned above. Especially designed for the remote control of CH4 gas via fibre optics, an integrated optoelectronic readout scheme has been developed and tested, It is shown that the proposed type of sensor can be used for the quantitative remote control of CH4 gas concentration (0.2-100%) via a fibre glass line up to a distance of 2 x 1 km. (C) 1997 Elsevier Science S.A.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos A1997YD90600029 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0924-4247; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.499 Times cited 3 Open Access
Notes Approved Most recent IF: 2.499; 1997 IF: 0.635
Call Number UA @ lucian @ c:irua:20455 Serial 1855
Permanent link to this record
 

 
Author (down) Volkov, V.V.; van Landuyt, J.; Amelinckx, S.; Pervov, V.S.; Makhonina, E.V.
Title Electron microscopic and X-ray structural analysis of the layered crystals TaReSe4: structure, defect structure, and microstructure, including rotation twins Type A1 Journal article
Year 1998 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 135 Issue Pages 235-255
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000072900200008 Publication Date 2002-10-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 3 Open Access
Notes Approved Most recent IF: 2.299; 1998 IF: 1.432
Call Number UA @ lucian @ c:irua:29672 Serial 938
Permanent link to this record
 

 
Author (down) Volkov, V.V.; van Heurck, C.; van Landuyt, J.; Amelinckx, S.; Zhukov, E.G.; Polulyak, E.S.; Novotortsev, V.M.
Title Electron microscopy and X-ray study of the growth of FeCr2S4 spinel single crystals by chemical vapour transport Type A1 Journal article
Year 1993 Publication Crystal research and technology Abbreviated Journal Cryst Res Technol
Volume 28 Issue 8 Pages 1051-1061
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The growth features of FeCr2S4 spinel single crystals prepared by chemical vapour transport were studied by means of scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy, electron diffraction and X-ray analysis. Our results indicate that the epitaxial growth of the new phases FeCr7S12 and FeCr8S12, both based on the NiAs structure, can essentially inhibit the growth of large FeCr2S4 spinel single crystals in the octahedral habit. The new phases are fully characterised and the effects of defect ordering in these new phases are also reported.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos A1993MN86700003 Publication Date 2007-01-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0232-1300;1521-4079; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.935 Times cited 1 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:6788 Serial 952
Permanent link to this record
 

 
Author (down) Volkov, V.V.; Luyten, W.; van Landuyt, J.; Férauge, C.; Oksenoid, K.G.; Gijbels, R.; Vasilev, M.G.; Shelyakin, A.A.; Lazarev, V.B.
Title Electron microscopy and mass-spectrometry study of In GaAsP/InP heterostructures (p-i-n diodes) grown by liquid phase epitaxy Type A1 Journal article
Year 1993 Publication Physica status solidi: A: applied research Abbreviated Journal
Volume 140 Issue Pages 73-85
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos A1993MM00800004 Publication Date 2007-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8965;1521-396X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 7 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:6159 Serial 945
Permanent link to this record
 

 
Author (down) Vlasov, I.L.; Lebedev, O.I.; Ralchenko, V.G.; Goovaerts, E.; Bertoni, G.; Van Tendeloo, G.; Konov, V.I.
Title Hybrid diamond-graphite nanowires produced by microwave plasma chemical vapor deposition Type A1 Journal article
Year 2007 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 19 Issue 22 Pages 4058-4062
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Nanostructured and organic optical and electronic materials (NANOrOPT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000251383900055 Publication Date 2007-11-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 75 Open Access
Notes Approved Most recent IF: 19.791; 2007 IF: NA
Call Number UA @ lucian @ c:irua:66983 Serial 1518
Permanent link to this record
 

 
Author (down) Vlasov, I.I.; Turner, S.; Van Tendeloo, G.; Shiryaev, A.A.
Title Recent results on characterization of detonation nanodiamonds Type H3 Book chapter
Year 2012 Publication Abbreviated Journal
Volume Issue Pages 291-322
Keywords H3 Book chapter; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Elsevier Place of Publication Amsterdam Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-1-4377-3465-2 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:105303 Serial 2840
Permanent link to this record
 

 
Author (down) Vlasov, I.I.; Shenderova, O.; Turner, S.; Lebedev, O.I.; Basov, A.A.; Sildos, I.; Rähn, M.; Shiryaev, A.A.; Van Tendeloo, G.
Title Nitrogen and luminescent nitrogen-vacancy defects in detonation nanodiamond Type A1 Journal article
Year 2010 Publication Small Abbreviated Journal Small
Volume 6 Issue 5 Pages 687-694
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract An efficient method to investigate the microstructure and spatial distribution of nitrogen and nitrogen-vacancy (N-V) defects in detonation nanodiamond (DND) with primary particle sizes ranging from approximately 3 to 50 nm is presented. Detailed analysis reveals atomic nitrogen concentrations as high as 3 at% in 50% of diamond primary particles with sizes smaller than 6 nm. A non-uniform distribution of nitrogen within larger primary DND particles is also presented, indicating a preference for location within the defective central part or at twin boundaries. A photoluminescence (PL) spectrum with well-pronounced zero-phonon lines related to the N-V centers is demonstrated for the first time for electron-irradiated and annealed DND particles at continuous laser excitation. Combined Raman and PL analysis of DND crystallites dispersed on a Si substrate leads to the conclusion that the observed N-V luminescence originates from primary particles with sizes exceeding 30 nm. These findings demonstrate that by manipulation of the size/nitrogen content in DND there are prospects for mass production of nanodiamond photoemitters based on bright and stable luminescence from nitrogen-related defects.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000275972400013 Publication Date 2010-01-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810;1613-6829; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 84 Open Access
Notes Esteem 026019 Approved Most recent IF: 8.643; 2010 IF: 7.336
Call Number UA @ lucian @ c:irua:82364 Serial 2341
Permanent link to this record
 

 
Author (down) Vlasov, I.I.; Barnard, A.S.; Ralchenko, V.G.; Lebedev, O.I.; Kanzyuba, M.V.; Saveliev, A.V.; Konov, V.I.; Goovaerts, E.
Title Nanodiamond photoemitters based on strong narrow-band luminescence from silicon-vacancy defects Type A1 Journal article
Year 2009 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 21 Issue 7 Pages 808-812
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Nanostructured and organic optical and electronic materials (NANOrOPT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000263737800012 Publication Date 2008-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 98 Open Access
Notes Approved Most recent IF: 19.791; 2009 IF: NA
Call Number UA @ lucian @ c:irua:74513 Serial 2253
Permanent link to this record
 

 
Author (down) Vlasov, E.; Skorikov, A.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Verbeeck, J.; Bals, S.
Title Secondary electron induced current in scanning transmission electron microscopy: an alternative way to visualize the morphology of nanoparticles Type A1 Journal article
Year 2023 Publication ACS materials letters Abbreviated Journal ACS Materials Lett.
Volume Issue Pages 1916-1921
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron tomography (ET) is a powerful tool to determine the three-dimensional (3D) structure of nanomaterials in a transmission electron microscope. However, the acquisition of a conventional tilt series for ET is a time-consuming process and can therefore not provide 3D structural information in a time-efficient manner. Here, we propose surface-sensitive secondary electron (SE) imaging as an alternative to ET for the investigation of the morphology of nanomaterials. We use the SE electron beam induced current (SEEBIC) technique that maps the electrical current arising from holes generated by the emission of SEs from the sample. SEEBIC imaging can provide valuable information on the sample morphology with high spatial resolution and significantly shorter throughput times compared with ET. In addition, we discuss the contrast formation mechanisms that aid in the interpretation of SEEBIC data.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001006191600001 Publication Date 2023-06-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2639-4979 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access OpenAccess
Notes The funding for this project was provided by European Research Council (ERC Consolidator Grant 815128, REALNANO). J.V. acknowledges the eBEAM project, which is supported by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 101017720 (FET-Proactive EBEAM). L.M.L.-M. acknowledges funding from MCIN/AEI/10.13039/501100011033 (grant # PID2020-117779RB-I00). Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:197004 Serial 8795
Permanent link to this record
 

 
Author (down) Vlasov, E.; Heyvaert, W.; Ni, B.; Van Gordon, K.; Girod, R.; Verbeeck, J.; Liz-Marzán, L.M.; Bals, S.
Title High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods Type A1 Journal Article
Year 2024 Publication ACS Nano Abbreviated Journal ACS Nano
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods. However, the technique is time-consuming and consequently lacks statistical value. To address this issue, we introduce herein a high-throughput methodology that combines images acquired by secondary electron-based electron beam-induced current (SEEBIC) with quantitative image analysis. As a result, the geometric chirality of hundreds of nanoparticles can be quantified in less than 1 h. When combining the drastic gain in data collection efficiency of SEEBIC with a limited number of ET data sets, a better understanding of how the chiral structure of individual chiral nanoparticles translates into the ensemble chiroptical response can be reached.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links
Impact Factor 17.1 Times cited Open Access
Notes The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.) and from MCIN/AEI/10.13039/501100011033 (Grant PID2020-117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021-097588 to K.V.G.). Funded by the European Union under Project 101131111 − DELIGHT, JV acknowledges the eBEAM project supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07- 2020: emerging paradigms and communities. Approved Most recent IF: 17.1; 2024 IF: 13.942
Call Number EMAT @ emat @ Serial 9121
Permanent link to this record
 

 
Author (down) Vlasov, E.; Denisov, N.; Verbeeck, J.
Title Low-cost electron detector for scanning electron microscope Type A1 Journal article
Year 2023 Publication HardwareX Abbreviated Journal HardwareX
Volume 14 Issue Pages e00413
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron microscopy is an indispensable tool for the characterization of (nano) materials. Electron microscopes are typically very expensive and their internal operation is often shielded from the user. This situation can provide fast and high quality results for researchers focusing on e.g. materials science if they have access to the relevant instruments. For researchers focusing on technique development, wishing to test novel setups, however, the high entry price can lead to risk aversion and deter researchers from innovating electron microscopy technology further. The closed attitude of commercial entities about how exactly the different parts of electron microscopes work, makes it even harder for newcomers in this field. Here we propose an affordable, easy-to-build electron detector for use in a scanning electron microscope (SEM). The aim of this project is to shed light on the functioning of such detectors as well as show that even a very modest design can lead to acceptable performance while providing high flexibility for experimentation and customization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001042486000001 Publication Date 2023-03-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2468-0672 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access OpenAccess
Notes The authors acknowledge the financial support of the Research Foundation Flanders (FWO, Belgium) project SBO [Grant No. S000121N]. JV acknowledges funding from the HORIZON-INFRA-2022-TECH-01-01 project IMPRESS [Grant No. 101094299]. Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:195886 Serial 7252
Permanent link to this record
 

 
Author (down) Vlasov, E.
Title Exploiting secondary electrons in transmission electron microscopy for 3D characterization of nanoparticle morphologies Type Doctoral thesis
Year 2024 Publication Abbreviated Journal
Volume Issue Pages x, 118 p.
Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)
Abstract Electron tomography (ET) is an indispensable tool for determining the three-dimensional (3D) structure of nanomaterials in (scanning) transmission electron microscopy ((S)TEM). ET enables 3D characterization of a variety of nanomaterials across different fields, including life sciences, chemistry, solid-state physics, and materials science down to atomic resolution. However, the acquisition of a conventional tilt series for ET is a time-consuming process and thus cannot capture fast transformations of materials in realistic conditions. Moreover, only a limited number of nanoparticles (NPs) can be investigated, hampering a general understanding of the average properties of the material. Therefore, alternative characterization techniques that allow for high-resolution characterization of the surface structure without the need to acquire a full tilt series in ET are required which would enable a more time-efficient investigation with better statistical value. In the first part of this work, an alternative technique for the characterization of the morphology of NPs to improve the throughput and temporal resolution of ET is presented. The proposed technique exploits surface-sensitive secondary electron (SE) imaging in STEM employed using a modification of electron beam-induced current (EBIC) setup. The time- and dose efficiency of SEEBIC are tested in comparison with ET and superior spatial resolution is shown compared to conventional scanning electron microscopy. Finally, contrast artefacts arising in SEEBIC images are described, and their origin is discussed. The second part of my thesis focuses on real applications of the proposed technique and introduces a high-throughput methodology that combines images acquired by SEEBIC with quantitative image analysis to retrieve information about the helicity of gold nanorods. It shows that SEEBIC imaging overcomes the limitation of ET providing a general understanding of the connection between structure and chiroptical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-06-17
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 Most recent IF: NA
Call Number UA @ admin @ c:irua:204905 Serial 9149
Permanent link to this record
 

 
Author (down) Vladimirova, S.A.; Rumyantseva, M.N.; Filatova, D.G.; Chizhov, A.S.; Khmelevsky, N.O.; Konstantinova, E.A.; Kozlovsky, V.F.; Marchevsky, A.V.; Karakulina, O.M.; Hadermann, J.; Gaskov, A.M.
Title Cobalt location in p -CoO x / n -SnO 2 nanocomposites: Correlation with gas sensor performances Type A1 Journal Article
Year 2017 Publication Journal Of Alloys And Compounds Abbreviated Journal J Alloy Compd
Volume 721 Issue Pages 249-260
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p – n junction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000405252400030 Publication Date 2017-06-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.133 Times cited Open Access Not_Open_Access
Notes This work was supported by ERA-Net.Plus grant N 096 FONSENS. EPR experiments were performed using the facilities of the Collective Use Center at the Moscow State University. Approved Most recent IF: 3.133
Call Number EMAT @ emat @ Serial 4711
Permanent link to this record
 

 
Author (down) Vladimirova, S.A.; Rumyantseva, M.N.; Filatova, D.G.; Chizhov, A.S.; Khmelevsky, N.O.; Konstantinova, E.A.; Kozlovsky, V.F.; Marchevsky, A.V.; Karakulina, O.M.; Hadermann, J.; Gaskov, A.M.
Title Cobalt location in p-CoOxIn-SnO2 nanocomposites : correlation with gas sensor performances Type A1 Journal article
Year 2017 Publication Journal of alloys and compounds Abbreviated Journal J Alloy Compd
Volume 721 Issue Pages 249-260
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p – n junction. (C) 2017 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388 ISBN Additional Links UA library record; ; WoS full record; WoS citing articles
Impact Factor 3.133 Times cited Open Access Not_Open_Access: Available from 10.10.2019
Notes ; This work was supported by ERA-Net.Plus grant N 096 FON-SENS. EPR experiments were performed using the facilities of the Collective Use Center at the Moscow State University. ; Approved Most recent IF: 3.133
Call Number UA @ lucian @ c:irua:145142 Serial 4714
Permanent link to this record
 

 
Author (down) Vladimirova, N.V.; Frolov, A.S.; Sanchez-Barriga, J.; Clark, O.J.; Matsui, F.; Usachov, D.Y.; Muntwiler, M.; Callaert, C.; Hadermann, J.; Neudachina, V.S.; Tamm, M.E.; Yashina, L.V.
Title Occupancy of lattice positions probed by X-ray photoelectron diffraction : a case study of tetradymite topological insulators Type A1 Journal article
Year 2023 Publication Surfaces and interfaces Abbreviated Journal
Volume 36 Issue Pages 102516-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Occupancy of different structural positions in a crystal lattice often seems to play a key role in material prop-erties. Several experimental techniques have been developed to uncover this issue, all of them being mostly bulk sensitive. However, many materials including topological insulators (TIs), which are among the most intriguing modern materials, are intended to be used in devices as thin films, for which the sublattice occupancy may differ from the bulk. One of the possible approaches to occupancy analysis is X-ray Photoelectron Diffraction (XPD), a structural method in surface science with chemical sensitivity. We applied this method in a case study of Sb2(Te1-xSex)3 mixed crystals, which belong to prototypical TIs. We used high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) as a reference method to verify our analysis. We revealed that the XPD data for vacuum cleaved bulk crystals are in excellent agreement with the reference ones. Also, we demonstrate that the anion occupancy near a naturally formed surface can be rather different from that of the bulk. The present results are relevant for a wide range of compositions where the system remains a topological phase, as we ultimately show by probing the transiently occupied topological surface state above the Fermi level by ultrafast photoemission.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000901694900001 Publication Date 2022-11-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2468-0230 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.2 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.2; 2023 IF: NA
Call Number UA @ admin @ c:irua:193502 Serial 7327
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Varandani, D.; Hendrickx, M.; Hadermann, J.; Mehta, B.R.
Title Nanoscale photovoltage mapping in CZTSe/CuxSe heterostructure by using kelvin probe force microscopy Type A1 Journal article
Year 2020 Publication Materials Research Express Abbreviated Journal
Volume 7 Issue 1 Pages 016418
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In the present work, kelvin probe force microscopy (KPFM) technique has been used to study the CZTSe/CuxSe bilayer interface prepared by multi-step deposition and selenization process of metal precursors. Transmission electron microscopy (TEM) confirmed the bilayer configuration of the CZTSe/CuxSe sample. Two configuration modes (surface mode and junction mode) in KPFM have been employed in order to measure the junction voltage under illumination conditions. The results show that CZTSe/CuxSe has small junction voltage of similar to 21 mV and the presence of CuxSe secondary phase in the CZTSe grain boundaries changes the workfunction of the local grain boundaries region. The negligible photovoltage difference between grain and grain boundaries in photovoltage image indicates that CuxSe phase deteriorates the higher photovoltage at grain boundaries normally observed in CZTSe based device. These results can be important for understanding the role of secondary phases in CZTSe based junction devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000520120900001 Publication Date 2019-12-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes ; Authors acknowledges support provided DST in the forms of InSOL and Indo-Swiss projects. We also acknowledge Joke Hadermann EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Belgium for helping in TEM measurements. M V Manoj Vishwakarma acknowledges IIT Delhi for MHRD fellowship. Prof B R Mehta acknowledges the support of the Schlumberger chair professorship. M V also acknowledges the support of DST-FIST Raman facility. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:167843 Serial 6567
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Thota, N.; Karakulina, O.; Hadermann, J.; Mehta, B.R.
Title Role of graphene inter layer on the formation of the MoS2 – CZTS interface during growth Type P1 Proceeding
Year 2018 Publication (icc-2017) Abbreviated Journal
Volume Issue Pages
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract The growth of MoS2 layer near the Mo/CZTS interface during sulphurization process can have an impact on back contact cell parameters (series resistance and fill factor) depending upon the thickness or quality of MoS2. This study reports the dependence of the thickness of interfacial MoS2 layer on the growth of graphene at the interface between molybdenum back contact and deposited CZTS layer. The graphene layer reduces the accumulation of Zn/ZnS, Sn/SnO2 and formation of pores near the MoS2-CZTS interface. The use of graphene as interface layer can be potentially useful for improving the quality of Mo/MoS2/CZTS interface.
Address
Corporate Author Thesis
Publisher Amer inst physics Place of Publication Melville Editor
Language Wos 000436313003046 Publication Date 2018-05-09
Series Editor Series Title Abbreviated Series Title
Series Volume 1953 Series Issue Edition
ISSN 978-0-7354-1648-2; 0094-243x; 0094-243x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access OpenAccess
Notes ; The authors acknowledge support provided by DST project. M.V. acknowledges IIT Delhi for MHRD fellowship. Prof. B. R. Mehta acknowledges the support of the Schlumberger chair professorship. ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:153203 Serial 5126
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Kumar, M.; Hendrickx, M.; Hadermann, J.; Singh, A.P.; Batra, Y.; Mehta, B.R.
Title Enhancing the hydrogen evolution properties of kesterite absorber by Si-doping in the surface of CZTS thin film Type A1 Journal article
Year 2021 Publication Advanced Materials Interfaces Abbreviated Journal Adv Mater Interfaces
Volume Issue Pages 2002124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this work, the effects of Si-doping in Cu2ZnSnS4 are examined computationally and experimentally. The density functional theory calculations show that an increasing concentration of Si (from x = 0 to x = 1) yields a band gap rise due to shifting of the conduction band minimum towards higher energy states in the Cu2Zn(Sn1-xSix)S-4. CZTSiS thin film prepared by co-sputtering process shows Cu2Zn(Sn1-xSix)S-4 (Si-rich) and Cu2ZnSnS4 (S-rich) kesterite phases on the surface and in the bulk of the sample, respectively. A significant change in surface electronic properties is observed in CZTSiS thin film. Si-doping in CZTS inverts the band bending at grain-boundaries from downward to upward and the Fermi level of CZTSiS shifts upward. Further, the coating of the CdS and ZnO layer improves the photocurrent to approximate to 5.57 mA cm(-2) at -0.41 V-RHE in the CZTSiS/CdS/ZnO sample, which is 2.39 times higher than that of pure CZTS. The flat band potential increases from CZTS approximate to 0.43 V-RHE to CZTSiS/CdS/ZnO approximate to 1.31 V-RHE indicating the faster carrier separation process at the electrode-electrolyte interface in the latter sample. CdS/ZnO layers over CZTSiS significantly reduce the charge transfer resistance at the semiconductor-electrolyte interface.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000635804900001 Publication Date 2021-04-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2196-7350 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.279 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.279
Call Number UA @ admin @ c:irua:177688 Serial 6780
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Karakulina, O.M.; Abakumov, A.M.; Hadermann, J.; Mehta, B.R.
Title Nanoscale Characterization of Growth of Secondary Phases in Off-Stoichiometric CZTS Thin Films Type A1 Journal article
Year 2018 Publication Journal of nanoscience and nanotechnology Abbreviated Journal J Nanosci Nanotechno
Volume 18 Issue 3 Pages 1688-1695
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The presence of secondary phases is one of the main issues that hinder the growth of pure kesterite Cu2ZnSnS4 (CZTS) based thin films with suitable electronic and junction properties for efficient solar cell devices. In this work, CZTS thin films with varied Zn and Sn content have been prepared by RF-power controlled co-sputtering deposition using Cu, ZnS and SnS targets and a subsequent sulphurization step. Detailed TEM investigations show that the film shows a layered structure with the majority of the top layer being the kesterite phase. Depending on the initial thin film composition, either about ~1 μm Cu-rich and Zn-poor kesterite or stoichiometric CZTS is formed as top layer. X-ray diffraction, Raman spectroscopy and transmission electron microscopy reveal the presence of Cu2−x S, ZnS and SnO2 minor secondary phases in the form of nanoinclusions or nanoparticles or intermediate layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000426033400022 Publication Date 2018-03-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1533-4880 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.483 Times cited Open Access Not_Open_Access
Notes Manoj Vishwakarma acknowl- edges IIT Delhi for MHRD fellowship. Professor B. R. Mehta acknowledges the support of the Schlumberger chair professorship. Manoj Vishwakarma, Joke Hadermann and Olesia M. karakulina acknowledge support provided by InsoL-DST. Manoj Vishwakarma acknowledges sup- port provided by CSIR funded projects and the support of DST-FIST Raman facility. References Approved Most recent IF: 1.483
Call Number EMAT @ emat @c:irua:147505 Serial 4775
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Batra, Y.; Hadermann, J.; Singh, A.; Ghosh, A.; Mehta, B.R.
Title Exploring the role of graphene oxide as a co-catalyst in the CZTS photocathodes for improved photoelectrochemical properties Type A1 Journal article
Year 2022 Publication ACS applied energy materials Abbreviated Journal
Volume 5 Issue 6 Pages 7538-7549
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The hydrogen evolution properties of CZTS heterostructure photocathodes are reported with graphene oxide (GO) as a co-catalyst layer coated by a drop-cast method and an Al2O3 protection layer fabricated using atomic layer deposition. In the CZTS absorber, a minor deviation from stoichiometry across the cross section of the thin film results in nanoscale growth of spurious phases, but the kesterite phase remains the dominant phase. We have investigated the band alignment parameters such as the band gap, work function, and Fermi level position that are crucial for making kesterite-based heterostructure devices. The photocurrent density in the photocathode CZTS/CdS/ZnO is found to be improved to -4.71 mAmiddotcm(-2) at -0.40 V-RHE, which is 3 times that of the pure CZTS. This enhanced photoresponse can be attributed to faster carrier separation at p-n junction regions driven by upward band bending at CZTS grain boundaries and the ZnO layer. GO as a co-catalyst over the heterostructure photocathode significantly improves the photocurrent density to -6.14 mAmiddotcm(-2) at -0.40 V-RHE by effective charge migration in the CZTS/CdS/ZnO/GO configuration, but the onset potential shifts only after application of the Al2O3 protection layer. Significant photocurrents of -29 mAmiddotcm(-2) at -0.40 V-RHE and -8 mAmiddotcm(-2) at 0 V-RHE are observed, with an onset potential of 0.7 V-RHE in CZTS/CdS/ZnO/GO/Al2O3. The heterostructure configuration and the GO co-catalyst reduce the charge-transfer resistance, while the Al2O3 top layer provides a stable photocurrent for a prolonged time (similar to 16 h). The GO co-catalyst increases the flat band potential from 0.26 to 0.46 V-RHE in CZTS/CdS/ZnO/GO, which supports the bias-induced band bending at the electrolyte-electrode interface.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000820418400001 Publication Date 2022-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.4
Call Number UA @ admin @ c:irua:189666 Serial 7082
Permanent link to this record
 

 
Author (down) Vishwakarma, M.; Agrawal, K.; Hadermann, J.; Mehta, B.R.
Title Investigating the effect of sulphurization on volatility of compositions in Cu-poor and Sn-rich CZTS thin films Type A1 Journal article
Year 2020 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 507 Issue Pages 145043
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In the present work, the Cu-poor and Sn-rich CZTS thin films were prepared in order to study the volatility of Sn with respect to other components. Thin film compositions were kept intentionally Sn-rich to understand the behaviour of loss and segregation of Sn during sulphurization. The homogeneous composition distribution in precursor thin films turns heterogeneous with a change in morphology after sulphurization. The inability of identifying nanoscale secondary phases in CZTS thin film by conventional analytical techniques such as XRD and Raman, can be fulfilled by employing HAADF-STEM analysis. XPS and HAADF-STEM analyses provide the quantification of nanoscale secondary phases across the thin film and surface, respectively. The volatility of Sn was revealed in the form of segregation in the middle layer of CZTS cross-sectional lamella rather than loss to annealing atmosphere. It was observed that among the cations of CZTS, Sn segregates more than Cu, while Zn segregates least. The nanoscale spurious phases were observed to vary across different regions in the sulphurized CZTS sample. The reactive annealing lead to grain growth and formation of grain boundary features in the CZTS thin films, where annealing significantly modifies the potential difference and band bending at grain boundaries with respect to intra-grains.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000520021200053 Publication Date 2019-12-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 4 Open Access OpenAccess
Notes ; Authors acknowledges support provided by DST, India in the forms of InSOL project. We also acknowledge Dr. Indrani Mishra for XPS measurements and DST-FIST Raman facility for Raman measurements. Manoj Vishwakarma acknowledges IIT Delhi, New Delhi, India for MHRD fellowship. Prof. B.R. Mehta acknowledges the support of the Schlumberger chair professorship. ; Approved Most recent IF: 6.7; 2020 IF: 3.387
Call Number UA @ admin @ c:irua:168603 Serial 6552
Permanent link to this record
 

 
Author (down) Villarreal, R.; Lin, P.-C.; Faraji, F.; Hassani, N.; Bana, H.; Zarkua, Z.; Nair, M.N.; Tsai, H.-C.; Auge, M.; Junge, F.; Hofsaess, H.C.; De Gendt, S.; De Feyter, S.; Brems, S.; Ahlgren, E.H.; Neyts, E.C.; Covaci, L.; Peeters, F.M.; Neek-Amal, M.; Pereira, L.M.C.
Title Breakdown of universal scaling for nanometer-sized bubbles in graphene Type A1 Journal article
Year 2021 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 21 Issue 19 Pages 8103-8110
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We report the formation of nanobubbles on graphene with a radius of the order of 1 nm, using ultralow energy implantation of noble gas ions (He, Ne, Ar) into graphene grown on a Pt(111) surface. We show that the universal scaling of the aspect ratio, which has previously been established for larger bubbles, breaks down when the bubble radius approaches 1 nm, resulting in much larger aspect ratios. Moreover, we observe that the bubble stability and aspect ratio depend on the substrate onto which the graphene is grown (bubbles are stable for Pt but not for Cu) and trapped element. We interpret these dependencies in terms of the atomic compressibility of the noble gas as well as of the adhesion energies between graphene, the substrate, and trapped atoms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000709549100026 Publication Date 2021-09-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 24 Open Access OpenAccess
Notes Approved Most recent IF: 12.712
Call Number UA @ admin @ c:irua:184137 Serial 6857
Permanent link to this record
 

 
Author (down) Villani, K.; Vermandel, W.; Smets, K.; Liang, D.; Van Tendeloo, G.; Martens, J.A.
Title Platinum particle size and support effects in NOx mediated carbon oxidation over platinum catalysts Type A1 Journal article
Year 2006 Publication Environmental science & technology Abbreviated Journal Environ Sci Technol
Volume 40 Issue 8 Pages 2727-2733
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Platinum metal was dispersed on microporous, mesoporous, and nonporous support materials including the zeolites Na-Y, Ba-Y, Ferrierite, ZSM-22, ETS-10, and AlPO-11, alumina, and titania. The oxidation of carbon black loosely mixed with catalyst powder was monitored gravimetrically in a gas stream containing nitric oxide, oxygen, and water. The carbon oxidation activity of the catalysts was found to be uniquely related to the Pt dispersion and little influenced by support type. The optimum dispersion is around 3-4% corresponding to relatively large Pt particle sizes of 2040 nm. The carbon oxidation activity reflects the NO oxidation activity of the platinum catalyst, which reaches an optimum in the 20-40 nm Pt particle size range. The lowest carbon oxidation temperatures were achieved with platinum loaded ZSM-22 and AlPO-11 zeolite crystallites bearing platinum of optimum dispersion on their external surfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000236992700038 Publication Date 2006-04-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936X;1520-5851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.198 Times cited 29 Open Access
Notes Comet; Goa Approved Most recent IF: 6.198; 2006 IF: 4.040
Call Number UA @ lucian @ c:irua:103628 Serial 2651
Permanent link to this record
 

 
Author (down) Villani, K.; Kirschhock, C.E.A.; Liang, D.; Van Tendeloo, G.; Martens, J.A.
Title Catalytic carbon oxidation over ruthenium-based catalysts Type A1 Journal article
Year 2006 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit
Volume 45 Issue 19 Pages 3106-3109
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000237533400016 Publication Date 2006-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851;1521-3773; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 36 Open Access
Notes Approved Most recent IF: 11.994; 2006 IF: 10.232
Call Number UA @ lucian @ c:irua:59449 Serial 291
Permanent link to this record
 

 
Author (down) Vijayakumar, J.; Savchenko, T.M.; Bracher, D.M.; Lumbeeck, G.; Béché, A.; Verbeeck, J.; Vajda, Š.; Nolting, F.; Vaz, Ca.f.; Kleibert, A.
Title Absence of a pressure gap and atomistic mechanism of the oxidation of pure Co nanoparticles Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal Nat Commun
Volume 14 Issue 1 Pages 174
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Understanding chemical reactivity and magnetism of 3<italic>d</italic>transition metal nanoparticles is of fundamental interest for applications in fields ranging from spintronics to catalysis. Here, we present an atomistic picture of the early stage of the oxidation mechanism and its impact on the magnetism of Co nanoparticles. Our experiments reveal a two-step process characterized by (i) the initial formation of small CoO crystallites across the nanoparticle surface, until their coalescence leads to structural completion of the oxide shell passivating the metallic core; (ii) progressive conversion of the CoO shell to Co<sub>3</sub>O<sub>4</sub>and void formation due to the nanoscale Kirkendall effect. The Co nanoparticles remain highly reactive toward oxygen during phase (i), demonstrating the absence of a pressure gap whereby a low reactivity at low pressures is postulated. Our results provide an important benchmark for the development of theoretical models for the chemical reactivity in catalysis and magnetism during metal oxidation at the nanoscale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000955726400021 Publication Date 2023-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited 1 Open Access OpenAccess
Notes Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, 200021160186 2002153540 ; EC | Horizon 2020 Framework Programme, 810310 823717 ; University of Basel | Swiss Nanoscience Institute, P1502 ; This work is funded by Swiss National Foundation (SNF) (Grants. No 200021160186 and 2002153540) and the Swiss Nanoscience Institut (SNI) (Grant No. SNI P1502). S.V. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 810310, which corresponds to the J. Heyrovsky Chair project (“ERA Chair at J. Heyrovský Institute of Physical Chemistry AS CR – The institutional approach towards ERA”). The funders had no role in the preparation of the article. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. We kindly acknowledge Anja Weber and Elisabeth Müller from PSI for their help in fabricating the sample markers. A.B. and J. Verbeeck received funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No. 823717 – ESTEEM3 reported Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number EMAT @ emat @c:irua:196738 Serial 8804
Permanent link to this record
 

 
Author (down) Vidick, D.; Ke, X.; Devillers, M.; Poleunis, C.; Delcorte, A.; Moggi, P.; Van Tendeloo, G.; Hermans, S.
Title Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers Type A1 Journal article
Year 2015 Publication Beilstein journal of nanotechnology Abbreviated Journal Beilstein J Nanotech
Volume 6 Issue 6 Pages 1287-1297
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Heterometal clusters containing Ru and Au, Co and/or Pt are anchored onto carbon nanotubes and nanofibers functionalized with chelating phosphine groups. The cluster anchoring yield is related to the amount of phosphine groups available on the nanocarbon surface. The ligands of the anchored molecular species are then removed by gentle thermal treatment in order to form nanoparticles. In the case of Au-containing clusters, removal of gold atoms from the clusters and agglomeration leads to a bimodal distribution of nanoparticles at the nanocarbon surface. In the case of Ru-Pt species, anchoring occurs without reorganization through a ligand exchange mechanism. After thermal treatment, ultrasmall (1-3 nm) bimetal Ru-Pt nanoparticles are formed on the surface of the nanocarbons. Characterization by high resolution transmission electron microscopy (HRTEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) confirms their bimetal nature on the nanoscale. The obtained bimetal nanoparticles supported on nanocarbon were tested as catalysts in ammonia synthesis and are shown to be active at low temperature and atmospheric pressure with very low Ru loading.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000355908400001 Publication Date 2015-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2190-4286; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.127 Times cited 7 Open Access
Notes 246791 Countatoms; 262348 Esmi Approved Most recent IF: 3.127; 2015 IF: 2.670
Call Number c:irua:126431 Serial 1420
Permanent link to this record