| |
Records |
|
Author |
d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Kalyuzhnaya, A.S.; Rozova, M.G.; Antipov, E.V.; Van Tendeloo, G. |
| |
Title |
Tetrahedral chain order in the Sr2Fe2O5 brownmillerite |
Type |
A1 Journal article |
| |
Year |
2008 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| |
Volume |
20 |
Issue |
22 |
Pages |
7188-7194 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract  |
The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| |
Language |
|
Wos |
000261002200039 |
Publication Date |
2008-10-25 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
9.466 |
Times cited |
64 |
Open Access |
|
| |
Notes |
Iap Vi |
Approved |
Most recent IF: 9.466; 2008 IF: 5.046 |
| |
Call Number |
UA @ lucian @ c:irua:72945 |
Serial |
3511 |
| Permanent link to this record |
| |
|
| |
|
Author |
Abakumov, A.M.; King, G.; Laurinavichute, V.K.; Rozova, M.G.; Woodward, P.M.; Antipov, E.V. |
| |
Title |
The crystal structure of \alpha-K3AIF6: elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| |
Volume |
48 |
Issue |
19 |
Pages |
9336-9344 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The crystal structure of α-K3AlF6 was solved and refined from a combination of powder X-ray and neutron diffraction data (a = 18.8385(3)Å, c = 33.9644(6)Å, S.G. I41/a, Z = 80, RP(X-ray) = 0.037, RP(neutron) = 0.053). The crystal structure is of the A2BB′X6 elpasolite type with the a = b ≈ ae√5, c = 4ae superstructure (ae, parameter of the elpasolite subcell) and rock-salt-type ordering of the K and Al cations over the B and B′ positions, respectively. The remarkable feature of α-K3AlF6 is a rotation of 2/5 of the AlF6 octahedra by π/4 around one of the crystal axes of the elpasolite subcell, coinciding with the 4-fold symmetry axes of the AlF6 octahedra. The rotation of the AlF6 octahedra replaces the corner-sharing between the K and Al polyhedra by edge-sharing, resulting in an increase of coordination numbers of the K cations at the B positions up to 7 and 8. Due to significant deformations of the K polyhedra, the corner-sharing connectivity of the octahedral elpasolite framework is broken and the rotations of the AlF6 octahedra do not have a cooperative character. Elpasolites and double perovskites with similar structural organization are discussed. The difference in ionic radii of the B and B′ cations as well as the tolerance factor are proposed to be the parameters governing the formation of elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
| |
Language |
|
Wos |
000270091000039 |
Publication Date |
2009-09-03 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.857 |
Times cited |
20 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
| |
Call Number |
UA @ lucian @ c:irua:79733 |
Serial |
568 |
| Permanent link to this record |
| |
|
| |
|
Author |
Batuk, D.; Batuk, M.; Abakumov, A.M.; Hadermann, J. |
| |
Title |
Synergy between transmission electron microscopy and powder diffraction : application to modulated structures |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Acta crystallographica: section B: structural science |
Abbreviated Journal |
Acta Crystallogr B |
| |
Volume |
71 |
Issue |
71 |
Pages |
127-143 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The crystal structure solution of modulated compounds is often very challenging, even using the well established methodology of single-crystal X-ray crystallography. This task becomes even more difficult for materials that cannot be prepared in a single-crystal form, so that only polycrystalline powders are available. This paper illustrates that the combined application of transmission electron microscopy (TEM) and powder diffraction is a possible solution to the problem. Using examples of anion-deficient perovskites modulated by periodic crystallographic shear planes, it is demonstrated what kind of local structural information can be obtained using various TEM techniques and how this information can be implemented in the crystal structure refinement against the powder diffraction data. The following TEM methods are discussed: electron diffraction (selected area electron diffraction, precession electron diffraction), imaging (conventional high-resolution TEM imaging, high-angle annular dark-field and annular bright-field scanning transmission electron microscopy) and state-of-the-art spectroscopic techniques (atomic resolution mapping using energy-dispersive X-ray analysis and electron energy loss spectroscopy). |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
| |
Language |
|
Wos |
000352166500002 |
Publication Date |
2015-04-01 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2052-5206; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.032 |
Times cited |
11 |
Open Access |
|
| |
Notes |
Fwo G039211n |
Approved |
Most recent IF: 2.032; 2015 IF: NA |
| |
Call Number |
c:irua:124411 |
Serial |
3408 |
| Permanent link to this record |
| |
|
| |
|
Author |
Alekseeva, A.M.; Abakumov, A.M.; Leither-Jasper, A.; Schnelle, W.; Prots, Y.; Van Tendeloo, G.; Antipov, E.V.; Grin, Y. |
| |
Title |
Spatial separation of covalent, ionic, and metallic interactions in Mg11Rh18B8 and Mg3Rh5B3 |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Chemistry: a European journal |
Abbreviated Journal |
Chem-Eur J |
| |
Volume |
19 |
Issue |
52 |
Pages |
17860-17870 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The crystal structures of Mg11Rh18B8 and Mg3Rh5B3 have been investigated by using single-crystal X-ray diffraction. Mg11Rh18B8: space group P4/mbm; a=17.9949(7), c=2.9271(1)angstrom; Z=2. Mg3Rh5B3: space group Pmma; a=8.450(2), b=2.8644(6), c=11.602(2)angstrom; Z=2. Both crystal structures are characterized by trigonal prismatic coordination of the boron atoms by rhodium atoms. The [BRh6] trigonal prisms form arrangements with different connectivity patterns. Analysis of the chemical bonding by means of the electron-localizability/electron-density approach reveals covalent BRh interactions in these arrangements and the formation of BRh polyanions. The magnesium atoms that are located inside the polyanions interact ionically with their environment, whereas, in the structure parts, which are mainly formed by Mg and Rh atoms, multicenter (metallic) interactions are observed. Diamagnetic behavior and metallic electron transport of the Mg11Rh18B8 and Mg3Rh5B3 phases are in agreement with the bonding picture and the band structure. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| |
Language |
|
Wos |
000328531000028 |
Publication Date |
2013-12-02 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0947-6539; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
5.317 |
Times cited |
5 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 5.317; 2013 IF: 5.696 |
| |
Call Number |
UA @ lucian @ c:irua:113697 |
Serial |
3064 |
| Permanent link to this record |
| |
|
| |
|
Author |
King, G.; Abakumov, A.M.; Hadermann, J.; Alekseeva, A.M.; Rozova, M.G.; Perkisas, T.; Woodward, P.M.; Van Tendeloo, G.; Antipov, E.V. |
| |
Title |
Crystal structure and phase transitions in Sr3WO6 |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| |
Volume |
49 |
Issue |
13 |
Pages |
6058-6065 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The crystal structures of the beta and gamma polymorphs of Sr3WO6 and the gamma <->beta phase transition have been investigated using electron diffraction, synchrotron X-ray powder diffraction, and neutron powder diffraction. The gamma-Sr3WO6 polymorph is stable above T-c approximate to 470 K and adopts a monoclinically distorted double perovskite A(2)BB'O-6= Sr2SrWO6 structure (space group Cc, a = 10.2363(1)angstrom, b= 17.9007(1)angstrom, c= 11.9717(1)angstrom, beta=125.585(1)degrees at T= 1373 K, Z=12, corresponding to a = a(p)+1/2b(p) – 1/2c(p), b =3/2b(p) + 3/2c(p), c =-b(p) + c(p), a(p),b(p), c(p), lattice vectors of the parent Fm (3) over barm double perovskite structure). Upon cooling it undergoes a continuous phase transition into the triclinically distorted beta-Sr3WO6 phase (space group Cl, a = 10.09497(3)angstrom, b = 17.64748(5)angstrom, c = 11.81400(3)angstrom, alpha = 89.5470(2)degrees, beta= 125.4529(2)degrees, gamma =90.2889(2)degrees at T= 300 K). Both crystal structures of Sr3WO6 belong to a family of double perovskites with broken corner sharing connectivity of the octahedral framework. A remarkable feature of the gamma-Sr3WO6 structure is a non-cooperative rotation of the WO6 octahedra. One third of the WO6 octahedra are rotated by 45 about either the bp or the cp axis of the parent double perovskite structure. As a result, the WO6 octahedra do not share corners but instead share edges with the coordination polyhedra of the Sr cations at the B positions increasing their coordination number from 6 to 7 or 8. The crystal structure of the beta-phase is very close to the structure of the gamma-phase; decreasing symmetry upon the gamma ->beta transformation occurs because of unequal octahedral rotation angles about the bp and cp axes and increasing distortions of the WO6 octahedra. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
| |
Language |
|
Wos |
000279211500036 |
Publication Date |
2010-06-09 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.857 |
Times cited |
18 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2010 IF: 4.326 |
| |
Call Number |
UA @ lucian @ c:irua:83877 |
Serial |
562 |
| Permanent link to this record |
| |
|
| |
|
Author |
King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. |
| |
Title |
The high-temperature polymorphs of K3AlF6 |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| |
Volume |
50 |
Issue |
16 |
Pages |
7792-7801 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
| |
Language |
|
Wos |
000293493100052 |
Publication Date |
2011-07-11 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.857 |
Times cited |
19 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2011 IF: 4.601 |
| |
Call Number |
UA @ lucian @ c:irua:91131 |
Serial |
1468 |
| Permanent link to this record |
| |
|
| |
|
Author |
Bagiński, M.; Pedrazo-Tardajos, A.; Altantzis, T.; Tupikowska, M.; Vetter, A.; Tomczyk, E.; Suryadharma, R.N.S.; Pawlak, M.; Andruszkiewicz, A.; Górecka, E.; Pociecha, D.; Rockstuhl, C.; Bals, S.; Lewandowski, W. |
| |
Title |
Understanding and Controlling the Crystallization Process in Reconfigurable Plasmonic Superlattices |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
| |
Volume |
|
Issue |
|
Pages |
acsnano.0c09746 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
| |
Abstract |
The crystallization of nanomaterials is a primary source of solid-state, photonic structures. Thus, a detailed understanding of this process is of paramount importance for the successful application of photonic nanomaterials in emerging optoelectronic technologies. While colloidal crystallization has been thoroughly studied, for example, with advanced in situ electron microscopy methods, the noncolloidal crystallization (freezing) of nanoparticles (NPs) remains so far unexplored. To fill this gap, in this work, we present proof-of principle experiments decoding a crystallization of reconfigurable assemblies of NPs at a solid state. The chosen material corresponds to an excellent testing bed, as it enables both in situ and ex situ investigation using X-ray diffraction (XRD), transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atomic force microscopy (AFM), and optical spectroscopy in visible and ultraviolet range (UV−vis) techniques. In particular, ensemble measurements with small-angle XRD highlighted the dependence of the correlation length in the NPs assemblies on the number of heating/cooling cycles and the rate of cooling. Ex situ TEM imaging further supported these results by revealing a dependence of domain size and structure on the sample preparation route and by showing we can control the domain size over 2 orders of magnitude. The application of HAADF-STEM tomography, combined with in situ thermal control, provided three-dimensional single-particle level information on the positional order evolution within assemblies. This combination of real and reciprocal space provides insightful information on the anisotropic, reversibly reconfigurable assemblies of NPs. TEM measurements also highlighted the importance of interfaces in the polydomain structure of nanoparticle solids, allowing us to understand experimentally observed differences in UV−vis extinction spectra of the differently prepared crystallites. Overall, the obtained results show that the combination of in situ heating HAADF-STEM tomography with XRD and ex situ TEM techniques is a powerful approach to study nanoparticle freezing processes and to reveal the crucial impact of disorder in the solid-state aggregates of NPs on their plasmonic properties. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000634569100101 |
Publication Date |
2021-02-23 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.942 |
Times cited |
10 |
Open Access |
OpenAccess |
| |
Notes |
Ministerstwo Nauki i Szkolnictwa Wyzszego, 0112/DIA/2019/48 ; European Commission, 731019 E171000009 (EUSMI) ; Narodowe Centrum Nauki, 2016/21/N/ST5/03356 ; Deutsche Forschungsgemeinschaft, RO 3640/12-1 ; Fundacja na rzecz Nauki Polskiej, First TEAM2016–2/15 ; European Research Council, 815128 (REALNANO) ; sygma; |
Approved |
Most recent IF: 13.942 |
| |
Call Number |
EMAT @ emat @c:irua:175872 |
Serial |
6673 |
| Permanent link to this record |
| |
|
| |
|
Author |
Dubourdieu, C.; Rauwel, E.; Roussel, H.; Ducroquet, F.; Hollaender, B.; Rossell, M.; Van Tendeloo, G.; Lhostis, S.; Rushworth, S. |
| |
Title |
Addition of yttrium into HfO2 films: microstructure and electrical properties |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Vac Sci Technol A |
| |
Volume |
27 |
Issue |
3 |
Pages |
503-514 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The cubic phase of HfO2 was stabilized by addition of yttrium in thin films grown on Si/SiO2 by metal-organic chemical vapor deposition. The cubic phase was obtained for contents of 6.5 at. % Y or higher at a temperature as low as 470 °C. The complete compositional range (from 1.5 to 99.5 at. % Y) was investigated. The crystalline structure of HfO2 was determined from x-ray diffraction, electron diffraction, and attenuated total-reflection infrared spectroscopy. For cubic films, the continuous increase in the lattice parameter indicates the formation of a solid-solution HfO2Y2O3. As shown by x-ray photoelectron spectroscopy, yttrium silicate is formed at the interface with silicon; the interfacial layer thickness increases with increasing yttrium content and increasing film thickness. The dependence of the intrinsic relative permittivity r as a function of Y content was determined. It exhibits a maximum of ~30 for ~8.8 at. % Y. The cubic phase is stable upon postdeposition high-temperature annealing at 900 °C under NH3. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| |
Language |
|
Wos |
000265739100016 |
Publication Date |
2009-05-02 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0734-2101; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
1.374 |
Times cited |
29 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 1.374; 2009 IF: 1.297 |
| |
Call Number |
UA @ lucian @ c:irua:77054 |
Serial |
58 |
| Permanent link to this record |
| |
|
| |
|
Author |
Vervloessem, E.; Gromov, M.; De Geyter, N.; Bogaerts, A.; Gorbanev, Y.; Nikiforov, A. |
| |
Title |
NH3and HNOxFormation and Loss in Nitrogen Fixation from Air with Water Vapor by Nonequilibrium Plasma |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
ACS Sustainable Chemistry and Engineering |
Abbreviated Journal |
|
| |
Volume |
11 |
Issue |
10 |
Pages |
4289-4298 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| |
Abstract |
The current global energy crisis indicated that increasing our
insight into nonfossil fuel nitrogen fixation pathways for synthetic fertilizer
production is more crucial than ever. Nonequilibrium plasma is a good candidate
because it can use N2 or air as a N source and water directly as a H source, instead
of H2 or fossil fuel (CH4). In this work, we investigate NH3 gas phase formation
pathways from humid N2 and especially humid air up to 2.4 mol % H2O (100%
relative humidity at 20 °C) by optical emission spectroscopy and Fouriertransform
infrared spectroscopy. We demonstrate that the nitrogen fixation
capacity is increased when water vapor is added, as this enables HNO2 and NH3
production in both N2 and air. However, we identified a significant loss
mechanism for NH3 and HNO2 that occurs in systems where these species are
synthesized simultaneously; i.e., downstream from the plasma, HNO2 reacts with NH3 to form NH4NO2, which rapidly decomposes
into N2 and H2O. We also discuss approaches to prevent this loss mechanism, as it reduces the effective nitrogen fixation when not
properly addressed and therefore should be considered in future works aimed at optimizing plasma-based N2 fixation. In-line removal
of HNO2 or direct solvation in liquid are two proposed strategies to suppress this loss mechanism. Indeed, using liquid H2O is
beneficial for accumulation of the N2 fixation products. Finally, in humid air, we also produce NH4NO3, from the reaction of HNO3
with NH3, which is of direct interest for fertilizer application. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000953337700001 |
Publication Date |
2023-03-13 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2168-0485 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
8.4 |
Times cited |
|
Open Access |
OpenAccess |
| |
Notes |
This research is supported by the Excellence of Science FWOFNRS project (NITROPLASM, FWO grant ID GoF9618n, EOS ID 30505023), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant No. 810182 − SCOPE ERC Synergy project), and the Fund for Scientific Research (FWO) Flanders Bioeconomy project (grant No. G0G2322N), funded by the European Union-NextGenerationEU. |
Approved |
Most recent IF: 8.4; 2023 IF: 5.951 |
| |
Call Number |
PLASMANT @ plasmant @c:irua:195878 |
Serial |
7254 |
| Permanent link to this record |
| |
|
| |
|
Author |
Sieger, M.; Pahlke, P.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Ottolinger, R.; Haenisch, J.; Holzapfel, B.; Usoskin, A.; Kursumovic, A.; MacManus-Driscoll, J.L.; Stafford, B.H.; Bauer, M.; Nielsch, K.; Schultz, L.; Huehne, R. |
| |
Title |
Tailoring microstructure and superconducting properties in thick BaHfO3 and Ba2YNb/Ta)O-6 doped YBCO films on technical templates |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
IEEE transactions on applied superconductivity |
Abbreviated Journal |
|
| |
Volume |
27 |
Issue |
4 |
Pages |
6601407 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The current transport capability of YBa2Cu3O7-x(YBCO) based coated conductors (CCs) is mainly limited by two features: the grain boundaries of the used textured template, which are transferred into the superconducting film through the buffer layers, and the ability to pin magnetic flux lines by incorporation of defined defects in the crystal lattice. By adjusting the deposition conditions, it is possible to tailor the pinning landscape in doped YBCO in order to meet specific working conditions (T, B) for CC applications. To study these effects, we deposited YBCO layers with a thickness of about 1-2 mu m using pulsed laser deposition on buffered rolling-assisted biaxially textured Ni-W substrates as well as on metal tapes having either an ion-beam-texturedYSZbuffer or an MgO layer textured by inclined substrate deposition. BaHfO3 and the mixed double-perovskite Ba2Y(Nb/Ta)O-6 were incorporated as artificial pinning centers in these YBCO layers. X-ray diffraction confirmed the epitaxial growth of the superconductor on these templates as well as the biaxially oriented incorporation of the secondary phase additions in the YBCO matrix. A critical current density J(c) of more than 2 MA/cm(2) was achieved at 77 K in self-field for 1-2 mu m thick films. Detailed TEM (transmission electron microscopy) studies revealed that the structure of the secondary phase can be tuned, forming c-axis aligned nanocolumns, ab-oriented platelets, or a combination of both. Transport measurements show that the J(c) anisotropy in magnetic fields is reduced by doping and the peak in the J(c) (theta) curves can be correlated to the microstructural features. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| |
Language |
|
Wos |
000394588100001 |
Publication Date |
2016-12-24 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1051-8223 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
|
Times cited |
12 |
Open Access |
OpenAccess |
| |
Notes |
; This work was supported by EUROTAPES, a collaborative project funded by the European Commission's Seventh Framework Program (FP7/2007-2013) under Grant Agreement no. 280432. ; |
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:141961 |
Serial |
4693 |
| Permanent link to this record |
| |
|
| |
|
Author |
Vodolazov, D.Y.; Peeters, F.M. |
| |
Title |
Origin of the hysteresis of the current voltage characteristics of superconducting microbridges near the critical temperature |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
84 |
Issue |
9 |
Pages |
094511 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The current voltage (IV) characteristics of short [with length L less than or similar to xi(T)] and long [L >> xi(T)] microbridges are theoretically investigated near the critical temperature of the superconductor. Calculations are made in the nonlocal (local) limit when the inelastic relaxation length due to electron-phonon interactions L(in) = (D tau(in))(1/2) is larger (smaller) than the temperature-dependent coherence length xi(T) (D is the diffusion coefficient, tau(in) is the inelastic relaxation time of the quasiparticle distribution function). We find that, in both limits, the origin of the hysteresis in the IV characteristics is mainly connected with the large time scale over which the magnitude of the order parameter varies in comparison with the time-scale variation of the superconducting phase difference across the microbridge in the resistive state. In the nonlocal limit, the time-averaged heating and cooling of quasiparticles are found in different areas of the microbridge, which are driven, respectively, by oscillations of the order parameter and the electric field. We show that, by introducing an additional term in the time-dependent Ginzburg-Landau equation, it is possible to take into account the cooling effect in the local limit too. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000294920900009 |
Publication Date |
2011-09-14 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| |
Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme“Scientific and educational personnel of innovative Russia in 2009-2013,” the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| |
Call Number |
UA @ lucian @ c:irua:105573 |
Serial |
2527 |
| Permanent link to this record |
| |
|
| |
|
Author |
Nguyen, N.T.T.; Peeters, F.M. |
| |
Title |
The breakdown of Kohn's theorem in few-electron parabolic quantum dots doped with a single magnetic impurity Mn2+ |
Type |
P1 Proceeding |
| |
Year |
2010 |
Publication |
Journal of physics : conference series
T2 – Conference on Quantum Dots 2010 (QD2010), APR 26-30, 2010, Nottingham, ENGLAND |
Abbreviated Journal |
|
| |
Volume |
|
Issue |
|
Pages |
012031-12034 |
| |
Keywords |
P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
The cyclotron resonance (CR) absorption spectrum is calculated for a II-VI parabolic quantum dot (QD) containing few electrons and a single magnetic dopant (Mn(2+)). We find that Kohn's theorem no longer holds for this system and that the CR spectrum depends on the number of electrons inside the QD. The electron-Mn-ion interaction strength can be tuned for example by the magnetic field and by moving the Mn-ion to different positions inside the QD. We demonstrate that due to the presence of the Mn-ion the relative motion of the electrons couple with their center-of-mass motion through the electron-Mn-ion spin-spin exchange term resulting in an electron-electron interaction dependence of the magneto-optical absorption spectrum. At the ferromagnetic-antiferromagnetic transition we observe significant discontinuities in the CR lines. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| |
Language |
|
Wos |
000294907400031 |
Publication Date |
2010-09-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
245 |
Series Issue |
|
Edition |
|
| |
ISSN |
1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:113080 |
Serial |
3572 |
| Permanent link to this record |
| |
|
| |
|
Author |
Sena, S.H.R.; Pereira, J.M.; Farias, G.A.; Peeters, F.M. |
| |
Title |
Cyclotron resonance of trilayer graphene |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
86 |
Issue |
8 |
Pages |
085412 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The cyclotron resonance energies, the corresponding oscillator strengths, and the cyclotron absorption spectrum for trilayer graphene are calculated for both ABA and ABC stacking. A gate potential across the stacked layers leads to (1) a reduction of the transition energies, (2) a lifting of the degeneracy of the zero Landau level, and (3) the removal of the electron-hole symmetry. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| |
Language |
|
Wos |
000307273100009 |
Publication Date |
2012-08-08 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| |
Notes |
; This work was supported by the National Council for the Improvement of Higher education (CAPES), the Brazilian Council for Research (CNPq), the Flemish Science Foundation (FWO-V1), the bilateral projects between Flanders and Brazil and the CNPq and FWO-V1, and the ESF-Eurographene project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| |
Call Number |
UA @ lucian @ c:irua:100815 |
Serial |
604 |
| Permanent link to this record |
| |
|
| |
|
Author |
Dirtu, A.C.; Buczyńska, A.J.; Godoi, A.F.L.; Favoreto, R.; Bencs, L.; Potgieter-Vermaak, S.S.; Godoi, R.H.M.; Van Grieken, R.; Van Vaeck, L. |
| |
Title |
Methods, fluxes and sources of gas phase alkyl nitrates in the coastal air |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Environmental monitoring and assessment |
Abbreviated Journal |
|
| |
Volume |
186 |
Issue |
10 |
Pages |
6445-6457 |
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
| |
Abstract |
The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO2 levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000341497800035 |
Publication Date |
2014-06-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1420-2026; 1573-2967 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
no |
| |
Call Number |
UA @ admin @ c:irua:118906 |
Serial |
8224 |
| Permanent link to this record |
| |
|
| |
|
Author |
Gatto Rotondo, G.; Darchuk, L.; Swaenen, M.; Van Grieken, R. |
| |
Title |
Micro-Raman and SEM analysis of minerals from the Darhib mine, Egypt |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Journal of analytical sciences, methods and instrumentation |
Abbreviated Journal |
|
| |
Volume |
2 |
Issue |
1 |
Pages |
42-47 |
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The Darhib mine is one of the several talc deposits in the Hamata area of southeastern Egypt. Several specimens of minerals coming from this mine were subjected to complementary investigation by micro-Raman spectrometry and scanning electron microscopy. The difficulty in their identification is the appearance of most of them: they are all very small and only visible under the mineral binocular microscope(×10 – ×40). They appear as small crystals in fissures and holes and a visual determination on colour and crystal gives only a guess of what kind of mineral it could be. Therefore, only after analyzing them by micro-Raman and scanning electron microscopy it was possible to identify their structure and they can be divided in three main groups: one is quite generic and several minerals of different species were identified, such as quartz, talc, mottramite and chrysocolla, very common in the talc mine (these ones are Si-based minerals); the other one is constituted by four samples which are Zn and/or Cu rich, which means minerals of the rosasite or aurichalcite groups; the last group is constituted by two samples containing mainly Pb.. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
|
Publication Date |
2012-03-31 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2164-2745; 2164-2753 |
ISBN |
|
Additional Links |
UA library record |
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
no |
| |
Call Number |
UA @ admin @ c:irua:102567 |
Serial |
8232 |
| Permanent link to this record |
| |
|
| |
|
Author |
Monico, L.; Sorace, L.; Cotte, M.; de Nolf, W.; Janssens, K.; Romani, A.; Miliani, C. |
| |
Title |
Disclosing the binding medium effects and the pigment solubility in the (photo)reduction process of chrome yellows (PbCrO4/PbCr1-xSxO4) |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
ACS Omega |
Abbreviated Journal |
|
| |
Volume |
4 |
Issue |
4 |
Pages |
6607-6619 |
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The darkening due to chemical alteration of chrome yellows (PbCrO4/PbCr1-xSxO4) is a phenomenon threatening a large number of 19th-20th century paintings, including the Amsterdam Sunflowers by Vincent van Gogh. Our earlier studies have proven that the alteration is due to a Cr(VI) -> Cr(III) reduction with Cr(V)-species that are formed as long-lived intermediates and that bCr(1-x)S(x)O(4) (0 < x <= 0.8) types undergo reduction more readily than monoclinic, S-free, PbCrO4. In this context, there is still lack of knowledge about the effects of the chemical properties of the binding medium (i.e., chemical composition and drying process) and the solubility of chrome yellows on the overall reduction pathways. Here, we study a series of naturally and photochemically aged mock-up paints prepared by mixing chrome yellow powders (PbCrO4/PbCr0.2S0.8O4) with either linseed oil or a water-based acrylic emulsion as the binding medium. Equivalent paints made up of the highly soluble K2CrO4 were also investigated and used as benchmarks to provide a more in-depth understanding of the influence of the solubility on the chromate reduction pathways in the two different binders. A combination of synchrotron radiation-based Cr K-edge X-ray absorption near edge structure (XANES), electron paramagnetic resonance (EPR), and UV-Visible spectroscopy measurements shows that: (1) the Cr(VI) reduction results from the interaction between the pigment and the binder; (2) the process is more significant in oil, giving rise to Cr(V)- and Cr(III)-species as well as oxidized organic compounds; (3) the lightfastness of the chrome yellow pigment is enhanced in the acrylic binder; and (4) the tendency toward chromium reduction increases with increasing solubility of the pigment. Based on our findings, we propose a scheme for the mechanism of the (photo)reduction process of chrome yellows in the oil and acrylic binder. Overall, our results provide new insights into the factors driving the degradation of lead chromate-based paints in artworks and contribute to the development of strategies for preserving them over time. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000466552500057 |
Publication Date |
2019-04-10 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2470-1343 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
|
Times cited |
4 |
Open Access |
|
| |
Notes |
; The research was financially supported by the European research project IPERION-CH, funded by the European Commission, H2020-INFRAIA-2014-2015 (grant agreement n. 654028), and by the project AMIS, within the program Dipartimenti di Eccellenza 2018-2022, funded by MIUR and University of Perugia. The University of Perugia is also acknowledged for financial support under the program “Ricerca di Base 2017”. L.S. acknowledges the financial support of Ente CRF. For the beamtime grants received, we thank the ESRF (experiment no. HG64 and in-house beamtimes). ; |
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ admin @ c:irua:160416 |
Serial |
5577 |
| Permanent link to this record |
| |
|
| |
|
Author |
Monico, L.; d'Acapito, F.; Cotte, M.; Janssens, K.; Romani, A.; Ricci, G.; Miliani, C.; Cartechini, L. |
| |
Title |
Total electron yield (TEY) detection mode Cr K-edge XANES spectroscopy as a direct method to probe the composition of the surface of darkened chrome yellow (PbCr1-xSxO4) and potassium chromate paints |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms |
Abbreviated Journal |
|
| |
Volume |
539 |
Issue |
|
Pages |
141-147 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Antwerp X-ray Imaging and Spectroscopy (AXIS) |
| |
Abstract |
The darkening of chromate-pigments, including chrome yellows (PbCr1-xSxO4), is a surface phenomenon affecting late 19th-early 20th c. paintings, such as those by Van Gogh. Exploring analytical strategies that contribute to a deep understanding of darkening is therefore significant for the long-term conservation of unique masterpieces. Here, we examined the capabilities of Cr K-edge XANES spectroscopy collected at the same time in X-ray fluorescence yield (XFY) and total electron yield (TEY) detection modes to selectively study the surface composition of darkened oil paint mock-ups composed of chrome yellow (PbCr0.2S0.8O4) or potassium chromate. By discussing advantages and drawbacks in using XFY/TEY modes in relation to XFY & mu;-XANES analysis from sectioned samples, we aim at assessing if TEY-XANES spectroscopy: (i) is a selective surface method to determine the abundance of different Cr-species from paint fragments; (ii) can contribute to optimize the analytical strategy by limiting time consuming sample preparation procedures; (iii) can decrease the probability of radiation damage. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
001041485400001 |
Publication Date |
2023-04-10 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0168-583x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
1.3 |
Times cited |
|
Open Access |
OpenAccess |
| |
Notes |
|
Approved |
Most recent IF: 1.3; 2023 IF: 1.109 |
| |
Call Number |
UA @ admin @ c:irua:198427 |
Serial |
8944 |
| Permanent link to this record |
| |
|
| |
|
Author |
Monico, L.; Janssens, K.; Vanmeert, F.; Cotte, M.; Brunetti, B.G.; van der Snickt, G.; Leeuwestein, M.; Plisson, J.S.; Menu, M.; Miliani, C. |
| |
Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : part 5 : effects of nonoriginal surface coatings into the nature and distribution of chromium and sulfur species in chrome yellow paints |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| |
Volume |
86 |
Issue |
21 |
Pages |
10804-10811 |
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The darkening of lead chromate yellow pigments, caused by a reduction of the chromate ions to Cr(III) compounds, is known to affect the appearance of several paintings by Vincent van Gogh. In previous papers of this series, we demonstrated that the darkening is activated by light and depends on the chemical composition and crystalline structure of the pigments. In this work, the results of Part 2 are extended and complemented with a new study aimed at deepening the knowledge of the nature and distribution of Cr and S species at the interface between the chrome yellow paint and the nonoriginal coating layer. For this purpose, three microsamples from two varnished paintings by Van Gogh and a waxed low relief by Gauguin (all originally uncoated) have been examined. Because nonoriginal coatings are often present in artwork by Van Gogh and contemporaries, the understanding of whether or not their application has influenced the morphological and/or physicochemical properties of the chrome yellow paint underneath is relevant in view of the conservation of these masterpieces. In all the samples studied, microscopic X-ray fluorescence (mu-XRF) and X-ray absorption near edge structure (mu-XANES) investigations showed that Cr(III)-based alteration products are present in the form of grains inside the coating (generally enriched of S species) and also homogeneously widespread at the paint surface. The distribution of Cr(III) species may be explained by the mechanical friction caused by the coating application by brush that picked up and redistributed the superficial Cr compounds, likely already present in the reduced state as result of the photodegradation process. The analysis of the XANES profiles allowed us to obtain new insights into the nature of the Cr(III) alteration products, that were identified as sulfate-, oxide-, organo-metal-, and chloride-based compounds. Building upon the knowledge acquired through the examination of original paint samples and from the investigation of aged model paints in the last Part 4 paper, in this study we aim to characterize a possible relation between the chemical composition of the coating and the chrome yellow degradation pathways by studying photochemically aged model samples covered with a dammar varnish contaminated with sulfide and sulfate salts. Cr speciation results did not show any evidence of the active role of the varnish and added S species on the reduction process of chrome yellows. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000344510200043 |
Publication Date |
2014-10-10 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
6.32 |
Times cited |
25 |
Open Access |
|
| |
Notes |
; This research was supported by the Italian projects PRIN (SICH) and PON (ITACHA). The text also presents results from Interuniversity Attraction Poles Programme Belgian Science Policy (S2-ART project S4DA), GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments EC-799 and EC-1051). L.M. acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam) and Muriel Geldof (Cultural Heritage Agency of The Netherlands) for selecting and sharing the information on the cross-section taken from Bank of the Seine. All the staff of the Van Gogh Museum, the Kroller-Muller Museum, and the Musee d'Orsay are acknowledged for the agreeable cooperation. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
| |
Call Number |
UA @ admin @ c:irua:122100 |
Serial |
5570 |
| Permanent link to this record |
| |
|
| |
|
Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Dik, J.; Radepont, M.; Hendriks, E.; Geldof, M.; Cotte, M. |
| |
Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 2 : original paint layer samples |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| |
Volume |
83 |
Issue |
4 |
Pages |
1224-1231 |
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO4 to Cr2O3·2H2O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000287176900012 |
Publication Date |
2011-02-14 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
6.32 |
Times cited |
84 |
Open Access |
|
| |
Notes |
; This research was funded by grants from ESRF (experiment EC-504) and by HASYLAB (experiments 11-20080130 EC and 11-20070157 EC) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Van Gogh Museum, Amsterdam, is acknowledged for their agreeable cooperation and for the authorization to publish the images of the paintings in this article. L.M. was financially supported by the Erasmus Placement in the framework of Lifelong Learning Programme (A.Y. 2009-2010). The EU Community's FP7 Research Infrastructures program under the CHARISMA Project (Grant Agreement 228330) is also acknowledged. ; |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
| |
Call Number |
UA @ admin @ c:irua:88795 |
Serial |
5571 |
| Permanent link to this record |
| |
|
| |
|
Author |
Peeters, M.; Compernolle, T.; Van Passel, S. |
| |
Title |
Influence of information provided at the moment of a fire alarm on the choice of exit |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Fire Safety Journal |
Abbreviated Journal |
Fire Safety J |
| |
Volume |
117 |
Issue |
|
Pages |
103221-103228 |
| |
Keywords |
A1 Journal article; Economics; Engineering Management (ENM); Center for Oncological Research (CORE) |
| |
Abstract |
The data generated in buildings are used for all types of purposes. The quality of information used in assisting people to escape an emergency situation is of importance. In practice today, none of the data-generating systems that aid in the escape from emergency situations is validated on a regular basis. This study is based on the smart building concept. The rationale behind this concept is to provide information about a building and the usage of that building at each moment in time. An experiment was conducted to measure the impact of different types of information on participants' choice of exit, exit time and distance travelled. Seven identical floors of one building were used with different setups to see if the choice of exit is influenced by the type of information provided at the moment of an alarm. It was found that the information does have a significant impact on the choice of exit, escape speed and distance travelled. Furthermore, it was shown that false information can increase the time it takes to leave the building and the distance travelled, impacting the survival rate. The more imperative information is visualised, the stronger its influence is on the choices made. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000579650800011 |
Publication Date |
2020-09-15 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0379-7112 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.1 |
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 3.1; 2020 IF: 1.165 |
| |
Call Number |
UA @ admin @ c:irua:175125 |
Serial |
6929 |
| Permanent link to this record |
| |
|
| |
|
Author |
van der Graaf, W.N.P.; Tempelman, C.H.L.; Hendriks, F.C.; Ruiz-Martinez, J.; Bals, S.; Weckhuysen, B.M.; Pidko, E.A.; Hensen, E.J.M. |
| |
Title |
Deactivation of Sn-Beta during carbohydrate conversion |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
| |
Volume |
564 |
Issue |
564 |
Pages |
113-122 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The deactivation of Sn-Beta zeolite catalyst during retro-aldolization and isomerization of glucose is investigated. Confocal fluorescence microscopy reveals that retro-aldolization of glucose in CH3OH at 160 degrees C is accompanied with the build-up of insoluble oligomeric deposits in the micropores, resulting in a rapid catalyst deactivation. These deposits accumulate predominantly in the outer regions of the zeolite crystals, which points to mass transport limitations. Glucose isomerization in water is not only accompanied by the formation of insoluble deposits in the micropores, but also by the structural degradation of the zeolite due to desilication and destannation. Enhanced and sustained catalytic performance can be achieved by using ethanol/water mixtures as the reaction solvent instead of water. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| |
Language |
|
Wos |
000443669800012 |
Publication Date |
2018-07-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0926-860x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.339 |
Times cited |
25 |
Open Access |
OpenAccess |
| |
Notes |
; This work was performed in the framework of the CatchBio programme and the Joint Scientific Thematic Research Programme funded by the The Netherlands Organization for Scientific Research (NWO) and the Chinese Ministry of Science and Technology. J.R.M. acknowledges the Dutch Science Foundation (NWO) for his personal VENI grant. ; |
Approved |
Most recent IF: 4.339 |
| |
Call Number |
UA @ lucian @ c:irua:153715UA @ admin @ c:irua:153715 |
Serial |
5088 |
| Permanent link to this record |
| |
|
| |
|
Author |
Batuk, D.; Batuk, M.; Tsirlin, A.A.; Hadermann, J.; Abakumov, A.M. |
| |
Title |
Trapping of Oxygen Vacancies at Crystallographic Shear Planes in Acceptor-Doped Pb-Based Ferroelectrics |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
| |
Volume |
54 |
Issue |
54 |
Pages |
14787-14790 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The defect chemistry of the ferroelectric material PbTiO3 after doping with Fe(III) acceptor ions is reported. Using advanced transmission electron microscopy and powder X-ray and neutron diffraction, we demonstrate that even at concentrations as low as circa 1.7% (material composition approximately ABO2.95), the oxygen vacancies are trapped into extended planar defects, specifically crystallographic shear planes. We investigate the evolution of these defects upon doping and unravel their detailed atomic structure using the formalism of superspace crystallography, thus unveiling their role in nonstoichiometry in the Pb-based perovskites. |
| |
Address |
Chemistry Department, Moscow State University, 119991, Moscow (Russia). artem.abakumov@uantwerpen.be |
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
English |
Wos |
000367723400031 |
Publication Date |
2015-10-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1433-7851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
11.994 |
Times cited |
3 |
Open Access |
|
| |
Notes |
A.M.A. is grateful to the Russian Science Foundation (grant 14-13-00680). AT was funded by the Mobilitas grant MTT77 of the ESF and by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
| |
Call Number |
c:irua:131104 |
Serial |
4080 |
| Permanent link to this record |
| |
|
| |
|
Author |
Monico, L.; Cartechini, L.; Rosi, F.; Chieli, A.; Grazia, C.; De Meyer, S.; Nuyts, G.; Vanmeert, F.; Janssens, K.; Cotte, M.; De Nolf, W.; Falkenberg, G.; Sandu, I.C.A.; Tveit, E.S.; Mass, J.; De Freitas, R.P.; Romani, A.; Miliani, C. |
| |
Title |
Probing the chemistry of CdS paints in The Scream by in situ noninvasive spectroscopies and synchrotron radiation x-ray techniques |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Science Advances |
Abbreviated Journal |
|
| |
Volume |
6 |
Issue |
20 |
Pages |
eaay3514 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The degradation of cadmium sulfide (CdS)-based oil paints is a phenomenon potentially threatening the iconic painting The Scream (ca. 1910) by Edvard Munch (Munch Museum, Oslo) that is still poorly understood. Here, we provide evidence for the presence of cadmium sulfate and sulfites as alteration products of the original CdS-based paint and explore the external circumstances and internal factors causing this transformation. Macroscale in situ noninvasive spectroscopy studies of the painting in combination with synchrotron-radiation x-ray microspectroscopy investigations of a microsample and artificially aged mock-ups show that moisture and mobile chlorine compounds are key factors for promoting the oxidation of CdS, while light (photodegradation) plays a less important role. Furthermore, under exposure to humidity, parallel/secondary reactions involving dissolution, migration through the paint, and recrystallization of water-soluble phases of the paint are associated with the formation of cadmium sulfates. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000533573300009 |
Publication Date |
2020-05-16 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2375-2548 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.6 |
Times cited |
4 |
Open Access |
|
| |
Notes |
; The research was financially supported by the European research project IPERION-CH, funded by the European Commission, H2020-INFRAIA-2014-2015 (grant agreement no. 654028); the project AMIS, within the program Dipartimenti di Eccellenza 2018-2022 (funded by MIUR and University of Perugia); and the program “Ricerca di Base 2017” (funded by University of Perugia). S.D.M. and K.J. acknowledge the GOA Project SolarPaint from the University of Antwerp Research Council and projects G056619N and G054719N from FWO (Brussels). F.V. and K.J. acknowledge support from Interreg Project Smart*Light and thank BELSPO (Brussels) for financial support via FED-tWIN mandate PRF055. L.M. acknowledges the Erasmus+ program (Staff Mobility for training, A. Y. 2018 to 2019) of the European Commission. In situ noninvasive analyses were performed using the European MOLAB platform, which is financially supported by the European project IPERION-CH. For the beamtime grants received, the authors thank the ESRF-ID21 beamline (experiment nos. HG32, HG64, and HG95), DESY-P06 beamline, a member of the Helmholtz Association HGF (experiment nos. I-20130221 EC and I-20160126 EC), and the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. ; |
Approved |
Most recent IF: 13.6; 2020 IF: NA |
| |
Call Number |
UA @ admin @ c:irua:169519 |
Serial |
6585 |
| Permanent link to this record |
| |
|
| |
|
Author |
da Pieve, F.; Hogan, C.; Lamoen, D.; Verbeeck, J.; Vanmeert, F.; Radepont, M.; Cotte, M.; Janssens, K.; Gonze, X.; Van Tendeloo, G. |
| |
Title |
Casting light on the darkening of colors in historical paintings |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| |
Volume |
111 |
Issue |
20 |
Pages |
208302-208305 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| |
Abstract |
The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify the composition of the damaged paint work and demonstrate possible physicochemical processes, induced by illumination and exposure to humidity and air, that cause photoactivation of the original pigment and the degradation of the secondary minerals. The results suggest a new path for the darkening process which was never considered by previous studies and prompt a critical examination of their findings. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| |
Language |
|
Wos |
000327244500003 |
Publication Date |
2013-11-15 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
8.462 |
Times cited |
30 |
Open Access |
|
| |
Notes |
Vortex; ERC FP7; COUNTATOMS; ECASJO_; |
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
| |
Call Number |
UA @ lucian @ c:irua:111396UA @ admin @ c:irua:111396 |
Serial |
287 |
| Permanent link to this record |
| |
|
| |
|
Author |
Houben, K.; Jochum, J.K.; Lozano, D.P.; Bisht, M.; Menendez, E.; Merkel, D.G.; Ruffer, R.; Chumakov, A., I; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Couet, S.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
| |
Title |
In situ study of the \alpha-Sn to \beta-Sn phase transition in low-dimensional systems : phonon behavior and thermodynamic properties |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
100 |
Issue |
7 |
Pages |
075408 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The densities of phonon states of thin Sn films on InSb substrates are determined during different stages of the alpha-Sn to beta-Sn phase transition using nuclear inelastic x-ray scattering. The vibrational entropy and internal energy per atom as a function of temperature are obtained by numerical integration of the phonon density of states. The free energy as a function of temperature for the nanoscale samples is compared to the free energy obtained from ab initio calculations of bulk tin in the alpha-Sn and beta-Sn phase. In thin films this phase transition is governed by the interplay between the vibrational behavior of the film (the phase transition is driven by the vibrational entropy) and the stabilizing influence of the substrate (which depends on the film thickness). This brings a deeper understanding of the role of lattice vibrations in the phase transition of nanoscale Sn. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000478992800005 |
Publication Date |
2019-08-08 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
| |
Notes |
; This work was supported by the Research Foundation Flanders (FWO) and the Concerted Research Action (Grant No. GOA14/007). K.H., S.C., D.P.L., and E.M. wish to thank the FWO for financial support. The authors gratefully acknowledge the European Synchrotron Radiation Facility (ESRF) for the granted beam time and the use of the in situ UHV preparation chamber. The authors thank B. Opperdoes for technical support and T. Peissker and R. Lieten for fruitful discussions. ; |
Approved |
Most recent IF: 3.836 |
| |
Call Number |
UA @ admin @ c:irua:161836 |
Serial |
5416 |
| Permanent link to this record |
| |
|
| |
|
Author |
Yang, C.H.; Peeters, F.M.; Xu, W. |
| |
Title |
Density of states and magneto-optical conductivity of graphene in a perpendicular magnetic field |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
20 |
Pages |
205428 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The density of states (DOS) and the optical conductivity of graphene is calculated in the presence of a perpendicular magnetic field and where scattering on charged and short-range impurities is included. The standard Kubo formula is employed where the self-energy induced by impurity scattering and the Green's function are calculated self-consistently including inter-Landau level (LL) coupling and screening effects. It is found that the scattering from those two types of impurities results in a symmetric LL broadening and asymmetric inter-LL coupling renormalizes the LL positions to lower energy. The peak position and intensity of the magneto-optical conductivity depends on the filling factor and the broadened DOS. Good agreement is found with recent cyclotron resonance measurements. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000284400700003 |
Publication Date |
2010-11-18 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
39 |
Open Access |
|
| |
Notes |
; This work was supported by the National Natural Science Foundation of China under Grant No. 10804053, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the Chinese Academy of Sciences and Department of Science and Technology of Yunnan Province. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:95543 |
Serial |
641 |
| Permanent link to this record |
| |
|
| |
|
Author |
Van der Donck, M.; Zarenia, M.; Peeters, F.M. |
| |
Title |
Strong valley Zeeman effect of dark excitons in monolayer transition metal dichalcogenides in a tilted magnetic field |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
97 |
Issue |
8 |
Pages |
081109 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The dependence of the excitonic photoluminescence (PL) spectrum of monolayer transition metal dichalcogenides (TMDs) on the tilt angle of an applied magnetic field is studied. Starting from a four-band Hamiltonian we construct a theory which quantitatively reproduces the available experimental PL spectra for perpendicular and in-plane magnetic fields. In the presence of a tilted magnetic field, we demonstrate that the dark exciton PL peaks brighten due to the in-plane component of the magnetic field and split for light with different circular polarizations as a consequence of the perpendicular component of the magnetic field. This splitting is more than twice as large as the splitting of the bright exciton peaks in tungsten-based TMDs. We propose an experimental setup that will allow for accessing the predicted splitting of the dark exciton peaks in the PL spectrum. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
| |
Language |
|
Wos |
000425603600001 |
Publication Date |
2018-02-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
|
| |
Notes |
; This Rapid Communication was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836 |
| |
Call Number |
UA @ lucian @ c:irua:149913UA @ admin @ c:irua:149913 |
Serial |
4948 |
| Permanent link to this record |
| |
|
| |
|
Author |
Miranda, L.P.; Milovanović, S.P.; Filho, R.N.C.; Peeters, F.M. |
| |
Title |
Hall and bend resistance of a phosphorene Hall bar |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
104 |
Issue |
3 |
Pages |
035401 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The dependence of the Hall and bend resistances on a perpendicular magnetic field and on vacancy defects in a four-terminal phosphorene single layer Hall bar is investigated. A tight-binding model in combination with the Landauer-Buttiker formalism is used to calculate the energy spectrum, the lead-to-lead transmissions, and the Hall and bend resistances of the system. It is shown that the terminals with zigzag edge orientation are responsible for the absence of quantized plateaus in the Hall resistance and peaks in the longitudinal resistance. A negative bend resistance in the ballistic regime is found due to the presence of high- and low-energy transport modes in the armchair and zigzag terminals, respectively. The system density of states, with single vacancy defects, shows that the presence of in-gap states is proportional to the number of vacancies. Quantized plateaus in the Hall resistance are only formed in a sufficiently clean system. The effects of different kinds of vacancies where the plateaus are destroyed and a diffusive regime appears in the bend resistance are investigated. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000669002000003 |
Publication Date |
2021-07-01 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
OpenAccess |
| |
Notes |
|
Approved |
Most recent IF: 3.836 |
| |
Call Number |
UA @ admin @ c:irua:179704 |
Serial |
6997 |
| Permanent link to this record |
| |
|
| |
|
Author |
Charalampopoulou, E.; Delville, R.; Verwerft, M.; Lambrinou, K.; Schryvers, D. |
| |
Title |
Transmission electron microscopy study of complex oxide scales on DIN 1.4970 steel exposed to liquid Pb-Bi eutectic |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Corrosion science |
Abbreviated Journal |
Corrosion Science |
| |
Volume |
147 |
Issue |
|
Pages |
22-31 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The deployment of Gen-IV lead-cooled fast reactors requires a good compatibility between the selected structural/cladding steels and the inherently corrosive heavy liquid metal coolant. An effective liquid metal corrosion mitigation strategy involves the in-situ steel passivation in contact with the oxygen-containing Pb-alloy coolant. Transmission electron microscopy was used in this work to study the multi-layered oxide scales forming on an austenitic stainless steel fuel cladding exposed to oxygen-containing (CO ≈ 10−6 mass%) static liquid leadbismuth eutectic (LBE) for 1000 h between 400 and 500 °C. The oxide scale constituents were analyzed, including the intertwined phases comprising the innermost biphasic layer. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000456902100003 |
Publication Date |
2018-10-31 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0010938X |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
|
Times cited |
5 |
Open Access |
OpenAccess |
| |
Notes |
The authors would like to thank J. Joris for the technical support during corrosion testing and J. Lim for the manufacturing and calibration of the oxygen sensors and oxygen pumps used in this work. E. Charalampopoulou personally thanks H. Heidari, S. Pourbabak, A. Orekhov (EMAT) and N. Cautaerts (EMAT, SCK•CEN), for their valuable help with the training of the FEI Tecnai Osiris S/TEM and Jeol 3000 S/ TEM, respectively, as well as S. Van den Broeck (EMAT), J. Pakarinen (SCK•CEN) and W. Van Renterghem (SCK•CEN) for FIB sample preparation. Moreover, the authors gratefully acknowledge the funding provided in the framework of the ongoing development of the MYRRHA irradiation facility. The research leading to these results falls within the framework of the European Energy Research Alliance Joint Programme on Nuclear Materials (EERA JPNM). |
Approved |
Most recent IF: NA |
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:157541 |
Serial |
5164 |
| Permanent link to this record |
| |
|
| |
|
Author |
Heyne, M.H.; de Marneffe, J.-F.; Nuytten, T.; Meersschaut, J.; Conard, T.; Caymax, M.; Radu, I.; Delabie, A.; Neyts, E.C.; De Gendt, S. |
| |
Title |
The conversion mechanism of amorphous silicon to stoichiometric WS2 |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
| |
Volume |
6 |
Issue |
15 |
Pages |
4122-4130 |
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| |
Abstract |
The deposition of ultra-thin tungsten films and their related 2D chalcogen compounds on large area dielectric substrates by gas phase reactions is challenging. The lack of nucleation sites complicates the adsorption of W-related precursors and subsequent sulfurization usually requires high temperatures. We propose here a technique in which a thin solid amorphous silicon film is used as reductant for the gas phase precursor WF6 leading to the conversion to metallic W. The selectivity of the W conversion towards the underlying dielectric surfaces is demonstrated. The role of the Si surface preparation, the conversion temperature, and Si thickness on the formation process is investigated. Further, the in situ conversion of the metallic tungsten into thin stoichiometric WS2 is achieved by a cyclic approach based on WF6 and H2S pulses at the moderate temperature of 450 1C, which is much lower than usual oxide sulfurization processes. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000430538000036 |
Publication Date |
2018-03-20 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2050-7526 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
5.256 |
Times cited |
4 |
Open Access |
OpenAccess |
| |
Notes |
This work was supported throughout a strategic fundamental research grant for M. H. by the agency Flanders innovation & entrepreneurship (VLAIO). |
Approved |
Most recent IF: 5.256 |
| |
Call Number |
PLASMANT @ plasmant @c:irua:150968 |
Serial |
4921 |
| Permanent link to this record |
