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Author Bruno-Alfonso, A.; Hai, G.-Q.; Peeters, F.M.; Yeo, T.; Ryu, S.R.; McCombe, B.D.
Title High energy transitions of shallow magneto-donors in a GaAs/Al0.3Ga0.7As multiple quantum well Type A1 Journal article
Year 2001 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 13 Issue Pages (down) 9761-9772
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000172233300007 Publication Date 2002-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 7 Open Access
Notes Approved Most recent IF: 2.649; 2001 IF: 1.611
Call Number UA @ lucian @ c:irua:37301 Serial 1426
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Author Martens, T.; Mihailova, D.; van Dijk, J.; Bogaerts, A.
Title Theoretical characterization of an atmospheric pressure glow discharge used for analytical spectrometry Type A1 Journal article
Year 2009 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 81 Issue 21 Pages (down) 9096-9108
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We have investigated the plasma processes in an atmospheric pressure glow discharge (APGD) in He used for analytical spectrometry by means of fluid and Monte Carlo (MC) simulations. Typical results include the potential and electric field distributions in the plasma, the density profiles of the various plasma species throughout the discharge, the mean electron energy, as well as the rates of the various collision processes in the plasma, and the relative importance of the different production and loss rates for the various species. The similarities and differences with low-pressure glow discharges are discussed. The main differences are a very small cathode dark space region and a large positive column as well as the dominant role of molecular ions. Some characteristic features of the APGD, such as the occurrence of the different spatial zones in the discharge, are illustrated, with links to experimental observations.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000276191900062 Publication Date 2009-10-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700;1520-6882; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 15 Open Access
Notes Approved Most recent IF: 6.32; 2009 IF: 5.214
Call Number UA @ lucian @ c:irua:79554 Serial 3604
Permanent link to this record
 
 
Author Hai, G.Q.; Peeters, F.M.
Title Magnetopolaron effect in parabolic quantum wells in tilted magnetic fields Type A1 Journal article
Year 1999 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 60 Issue Pages (down) 8984-8991
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000082868800089 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 36 Open Access
Notes Approved Most recent IF: 3.836; 1999 IF: NA
Call Number UA @ lucian @ c:irua:27007 Serial 1922
Permanent link to this record
 
 
Author Savina, A.A.; Morozov, V.A.; Buzlukov, A.L.; Arapova, I.Y.; Stefanovich, S.Y.; Baklanova, Y.V.; Denisova, T.A.; Medvedeva, N.I.; Bardet, M.; Hadermann, J.; Lazoryak, B.I.; Khaikina, E.G.
Title New solid electrolyte Na9Al(MoO4)6 : structure and Na+ ion conductivity Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 20 Pages (down) 8901-8913
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract <script type='text/javascript'>document.write(unpmarked('Solid electrolytes are important materials with a wide range of technological applications. This work reports the crystal structure and electrical properties of a new solid electrolyte Na9Al(MoO4)(6). The monoclinic Na9Al(MoO4)(6) consists of isolated polyhedral, [Al(MoO4)(6)](9-) clusters composed of a central AlO6 octahedron sharing vertices with six MoO4 tetrahedra to form a three-dimensional framework. The AlO6 octahedron also shares edges with one NalO(6) octahedron and two Na2O(6) octahedra. Na3-Na5 atoms are located in the framework cavities. The structure is related to that of sodium ion conductor II-Na3Fe2(AsO4)(3). High-temperature conductivity measurements revealed that the conductivity (sigma) of Na9Al(MoO4)(6) at 803 K equals 1.63 X 10(-2) S cm(-1). The temperature behavior of the Na-23 and Al-27 nuclear magnetic resonance spectra and the spin-lattice relaxation rates of the Na-23 nuclei indicate the presence of fast Na+ ion diffusion in the studied compound. At T\u003C490 K, diffusion occurs by means of Na+ ion jumps exclusively through the sublattice of Na3-Na5 positions, whereas Na1 and Na2 become involved in the diffusion processes (through chemical exchange with the Na3-Na5 sublattice) only at higher temperatures.'));
Address
Corporate Author Thesis
Publisher American Chemical Society Place of Publication Washington, D.C Editor
Language Wos 000413884900037 Publication Date 2017-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 13 Open Access OpenAccess
Notes ; The research was performed within the state assignment of FASO of Russia (Themes 01201463330, A16-116122810214-9, and 0339-2016-0007), supported in part by the Russian Foundation for Basic Research (Projects 16-03-00510, 16-03-00164, and 17-03-00333). ; Approved Most recent IF: 9.466
Call Number UA @ lucian @ c:irua:147432 Serial 4886
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Author Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J.
Title Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 20 Pages (down) 8811-8823
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000413884900028 Publication Date 2017-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 7 Open Access Not_Open_Access
Notes This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. Approved Most recent IF: 9.466
Call Number EMAT @ emat @c:irua:147241 Serial 4768
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Author Brito, B.G.A.; Hai, G.-Q.; Teixeira Rabelo, J.N.; Cândido, L.
Title A quantum Monte Carlo study on electron correlation in all-metal aromatic clusters MAl4 – (M = Li, Na, K, Rb, Cu, Ag and Au) Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 18 Pages (down) 8639-8645
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using fixed-node diffusion quantum Monte Carlo (FN-DMC) simulation we investigate the electron correlation in all-metal aromatic clusters MAl4- (with M = Li, Na, K, Rb, Cu, Ag and Au). The electron detachment energies and electron affinities of the clusters are obtained. The vertical electron detachment energies obtained from the FN-DMC calculations are in very good agreement with the available experimental results. Calculations are also performed within the Hartree-Fock approximation, density-functional theory (DFT), and the couple-cluster (CCSD(T)) method. From the obtained results, we analyse the impact of the electron correlation effects in these bimetallic clusters and find that the correlation of the valence electrons contributes significantly to the detachment energies and electron affinities, varying between 20% and 50% of their total values. Furthermore, we discuss the electron correlation effects on the stability of the clusters as well as the accuracy of the DFT and CCSD(T) calculations in the present systems.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000334602900052 Publication Date 2014-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 10 Open Access
Notes ; This research was supported by CNPq, FAPESP and FAPEG (Brazil). ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:117247 Serial 2781
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Author Hai, G.Q.; Studart, N.; Peeters, F.M.
Title Multisubband electron transport in δ-doped semiconductor systems Type A1 Journal article
Year 1995 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 52 Issue Pages (down) 8363-8371
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1995RV81800091 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 0163-1829 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.736 Times cited 65 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:12194 Serial 2242
Permanent link to this record
 
 
Author Hai; Studart; Peeters, F.M.
Title Multisubband electron-transport in delta-doped semiconductor systems Type A1 Journal article
Year 1995 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 52 Issue 11 Pages (down) 8363-8371
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electron transport properties in delta-doped semiconductor systems-are studied. The subband electronic structure of the delta-doped system is obtained by solving the coupled Schrodinger and Poisson equations. The screening of the quasi-two-dimensional electron gas is taken into account for the ionized impurity scattering through the matrix dielectric function within the random-phase approximation. The quantum and transport mobilities are calculated numerically as a function of the total electron density and the width of the doped layer at zero temperature. The intersubband scattering and the effect of empty subbands above the Fermi level on the electron mobilities are investigated. The calculated mobilities are in reasonable agreement with the available experimental results.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1995RV81800091 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.736 Times cited 67 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:95353 Serial 2243
Permanent link to this record
 
 
Author Hai, G.Q.; Peeters, F.M.; Studart, N.; Wang, Y.J.; McCombe, B.D.
Title Interface effects on magnetopolarons in GaAs/AlxGa1-xAs quantum wells at high magnetic fields Type A1 Journal article
Year 1998 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 58 Issue Pages (down) 7822-7829
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000076130500055 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 8 Open Access
Notes Approved Most recent IF: 3.836; 1998 IF: NA
Call Number UA @ lucian @ c:irua:24161 Serial 1693
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Author Nicholas, R.J.; Sasaki, S.; Miura, N.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Devreese, J.T.; Lawless, M.J.; Ashenford, D.E.; Lunn, B.
Title Interband magnetooptical studies of resonant polaron coupling in CdTe/Cd1-xMnxTe quantum-wells Type A1 Journal article
Year 1994 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 50 Issue 11 Pages (down) 7596-7601
Keywords A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract Magnetoreflectivity measurements of the 1s and 2s exciton energies in a CdTe/Cd1-xMnxTe superlattice have been made in magnetic fields up to 45 T, showing the resonant polaron coupling of electrons to LO phonons. Strong reflectivity features are seen for both the 1s and 2s excitons, which show a strong field-dependent spin splitting due to the dilute magnetic barriers. At B-z=0, the 2s exciton feature is observed lying 18 meV above the Is state, and is shifted upward in energy by the magnetic fields. No resonant behavior occurs when the 2s state passes through the LO-phonon energy of 21 meV, but at higher fields of around 20 T, the resonances for both spin states (sigma(+/-)) of the 2s exciton broaden and show a strong anticrossing behavior. These experiments are shown to be in excellent agreement with a theoretical treatment which includes the resonant polaron coupling of the electrons alone. Both experiment and theory demonstrate an extremely strong resonant splitting of the 2s exciton states of approximately 11 meV, which is over 50% of the LO-phonon energy. The dominance of single-particle polaron coupling is attributed to the relative sizes of the polaron (35 Angstrom A) and the exciton (50 Angstrom A) radius.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1994PJ43700045 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.736 Times cited 10 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:99837 Serial 1687
Permanent link to this record
 
 
Author Mikhailova, D.; Karakulina, O.M.; Batuk, D.; Hadermann, J.; Abakumov, A.M.; Herklotz, M.; Tsirlin, A.A.; Oswald, S.; Giebeler, L.; Schmidt, M.; Eckert, J.; Knapp, M.; Ehrenberg, H.
Title Layered-to-Tunnel Structure Transformation and Oxygen Redox Chemistry in LiRhO2upon Li Extraction and Insertion Type A1 Journal article
Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 55 Issue 55 Pages (down) 7079-7089
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Layered Li(M,Li)O2 (where M is a transition metal) ordered rock-salt-type structures are used in advanced metal-ion batteries as one of the best hosts for the reversible intercalation of Li ions. Besides the conventional redox reaction involving oxidation/reduction of the M cation upon Li extraction/insertion, creating oxygen-located holes because of the partial oxygen oxidation increases capacity while maintaining the oxidized oxygen species in the lattice through high covalency of the M–O bonding. Typical degradation mechanism of the Li(M,Li)O2 electrodes involves partially irreversible M cation migration toward the Li positions, resulting in gradual capacity/voltage fade. Here, using LiRhO2 as a model system (isostructural and isoelectronic to LiCoO2), for the first time, we demonstrate an intimate coupling between the oxygen redox and M cation migration. A formation of the oxidized oxygen species upon electrochemical Li extraction coincides with transformation of the layered Li1–xRhO2 structure into the γ-MnO2-type rutile–ramsdellite intergrowth LiyRh3O6 structure with rutile-like [1 × 1] channels along with bigger ramsdellite-like [2 × 1] tunnels through massive and concerted Rh migration toward the empty positions in the Li layers. The oxidized oxygen dimers with the O–O distances as short as 2.26 Å are stabilized in this structure via the local Rh–O configuration reminiscent to that in the μ-peroxo-μ-hydroxo Rh complexes. The LiyRh3O6 structure is remarkably stable upon electrochemical cycling illustrating that proper structural implementation of the oxidized oxygen species can open a pathway toward deliberate employment of the anion redox chemistry in high-capacity/high-voltage positive electrodes for metal-ion batteries. Upon chemical or electrochemical oxidation, layered LiRhO2 shows a unique structural transformation that involves both cation migration and oxidation of oxygen resulting in a stable tunnel-like rutile−ramsdellite intergrowth LiyRh3O6 structure. This structure demonstrates excellent performance with the steady and reversible capacity of ∼200 mAh/g. The stability of LiyRh3O6 is rooted in the accommodation of partially oxidized oxygen species through the formation of short O−O distances that are compatible with the connectivity of RhO6 octahedra.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000380181400035 Publication Date 2016-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 12 Open Access
Notes Bundesministerium fur Bildung und Forschung, 03SF0477B ; Fonds Wetenschappelijk Onderzoek, G040116N ; Approved Most recent IF: 4.857
Call Number EMAT @ emat @ c:irua:140848 Serial 4424
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Author Clavel, J.; Lembrechts, J.; Lenoir, J.; Haider, S.; McDougall, K.; Nunez, M.A.; Alexander, J.; Barros, A.; Milbau, A.; Seipel, T.; Pauchard, A.; Fuentes-Lillo, E.; Backes, A.R.; Dar, P.; Reshi, Z.A.; Aleksanyan, A.; Zong, S.; Sierra, J.R.A.; Aschero, V.; Verbruggen, E.; Nijs, I.
Title Roadside disturbance promotes plant communities with arbuscular mycorrhizal associations in mountain regions worldwide Type A1 Journal article
Year 2024 Publication Ecography Abbreviated Journal
Volume Issue Pages (down) e07051-14
Keywords A1 Journal article; Plant and Ecosystems (PLECO) – Ecology in a time of change
Abstract We assessed the impact of road disturbances on the dominant mycorrhizal types in ecosystems at the global level and how this mechanism can potentially lead to lasting plant community changes. We used a database of coordinated plant community surveys following mountain roads from 894 plots in 11 mountain regions across the globe in combination with an existing database of mycorrhizal-plant associations in order to approximate the relative abundance of mycorrhizal types in natural and disturbed environments. Our findings show that roadside disturbance promotes the cover of plants associated with arbuscular mycorrhizal (AM) fungi. This effect is especially strong in colder mountain environments and in mountain regions where plant communities are dominated by ectomycorrhizal (EcM) or ericoid-mycorrhizal (ErM) associations. Furthermore, non-native plant species, which we confirmed to be mostly AM plants, are more successful in environments dominated by AM associations. These biogeographical patterns suggest that changes in mycorrhizal types could be a crucial factor in the worldwide impact of anthropogenic disturbances on mountain ecosystems. Indeed, roadsides foster AM-dominated systems, where AM-fungi might aid AM-associated plant species while potentially reducing the biotic resistance against invasive non-native species, often also associated with AM networks. Restoration efforts in mountain ecosystems will have to contend with changes in the fundamental make-up of EcM- and ErM plant communities induced by roadside disturbance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001198654900001 Publication Date 2024-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0906-7590 ISBN Additional Links UA library record; WoS full record
Impact Factor 5.9 Times cited Open Access
Notes Approved Most recent IF: 5.9; 2024 IF: 4.902
Call Number UA @ admin @ c:irua:205605 Serial 9224
Permanent link to this record
 
 
Author Sreepal, V.; Yagmurcukardes, M.; Vasu, K.S.; Kelly, D.J.; Taylor, S.F.R.; Kravets, V.G.; Kudrynskyi, Z.; Kovalyuk, Z.D.; Patane, A.; Grigorenko, A.N.; Haigh, S.J.; Hardacre, C.; Eaves, L.; Sahin, H.; Geim, A.K.; Peeters, F.M.; Nair, R.R.
Title Two-dimensional covalent crystals by chemical conversion of thin van der Waals materials Type A1 Journal article
Year 2019 Publication Nano letters Abbreviated Journal Nano Lett
Volume 19 Issue 9 Pages (down) 6475-6481
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Most of the studied two-dimensional (2D) materials have been obtained by exfoliation of van der Waals crystals. Recently, there has been growing interest in fabricating synthetic 2D crystals which have no layered bulk analogues. These efforts have been focused mainly on the surface growth of molecules in high vacuum. Here, we report an approach to making 2D crystals of covalent solids by chemical conversion of van der Waals layers. As an example, we used 2D indium selenide (InSe) obtained by exfoliation and converted it by direct fluorination into indium fluoride (InF3), which has a nonlayered, rhombohedral structure and therefore cannot possibly be obtained by exfoliation. The conversion of InSe into InF3 is found to be feasible for thicknesses down to three layers of InSe, and the obtained stable InF3 layers are doped with selenium. We study this new 2D material by optical, electron transport, and Raman measurements and show that it is a semiconductor with a direct bandgap of 2.2 eV, exhibiting high optical transparency across the visible and infrared spectral ranges. We also demonstrate the scalability of our approach by chemical conversion of large-area, thin InSe laminates obtained by liquid exfoliation, into InF3 films. The concept of chemical conversion of cleavable thin van der Waals crystals into covalently bonded noncleavable ones opens exciting prospects for synthesizing a wide variety of novel atomically thin covalent crystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000486361900083 Publication Date 2019-08-20
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 32 Open Access
Notes ; This work was supported by the Royal Society, the European Research Council (contract 679689 and EvoluTEM 715502), and Engineering and Physical Sciences Research Council, U.K. (EP/N013670/1), The authors acknowledge the use of the facilities at the Henry Royce Institute for Advanced Materials and associated support services. H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 117F095. M.Y. acknowledges the Flemish Science Foundation (FWO-Vl) for a postdoctoral fellowship. S.J.H. and D.J.K. acknowledge support from EPSRC (EP/P009050/1) and the NowNANO CDT. ; Approved Most recent IF: 12.712
Call Number UA @ admin @ c:irua:162818 Serial 5431
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Author Rakesh Roshan, S.C.; Yedukondalu, N.; Pandey, T.; Kunduru, L.; Muthaiah, R.; Rajaboina, R.K.; Ehm, L.; Parise, J.B.
Title Effect of atomic mass contrast on lattice thermal conductivity : a case study for alkali halides and alkaline-earth chalcogenides Type A1 Journal article
Year 2023 Publication ACS applied electronic materials Abbreviated Journal
Volume 5 Issue 11 Pages (down) 5852-5863
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Lattice thermal conductivity (kappa(L)) is of great scientific interest for the development of efficient energy conversion technologies. Therefore, microscopic understanding of phonon transport is critically important for designing functional materials. In our previous study (Roshan et al., ACS Applied Energy Mater. 2021, 5, 882-896), anomalous kappa(L) trends were predicted for rocksalt alkaline-earth chalcogenides (AECs). In the present work, we extended it to alkali halides (AHs) and conducted a thorough investigation to explore the role of atomic mass contrast on lattice dynamics and phonon transport properties of 36 binary compounds (20 AHs + 16 AECs). The calculated spectral and cumulative kappa(L) reveal that low-lying optical phonon modes significantly boost kappa(L) alongside acoustic phonons in materials where the atomic mass ratio approaches unity and cophonocity nears zero. Phonon scattering rates are relatively low for materials with a mass ratio close to one, and the corresponding phonon lifetimes are higher, which enhances kappa(L). Phonon lifetimes play a critical role, outweighing phonon group velocities, in determining the anomalous trends in kappa(L) for both AHs and AECs. To further explore the role of atomic mass contrast in kappa(L), the effect of tensile lattice strain on phonon transport has also been investigated. Under tensile strain, both group velocities and phonon lifetimes decrease in the low frequency range, leading to a decrease in kappa(L). This work provides insights on how atomic mass contrast can tune the contribution of optical phonons to kappa(L) and its implications on scattering rates by either enhancing or suppressing kappa(L). These insights would aid in the selection of elements for designing new functional materials with and without atomic mass contrast to achieve relatively high and low kappa(L) values, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001096792500001 Publication Date 2023-10-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2637-6113 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:201198 Serial 9026
Permanent link to this record
 
 
Author Hai, G.-Q.; Studart, N.; Peeters, F.M.; Koenraad, P.M.; Wolter, J.H.
Title Intersubband-coupling and screening effects on the electron transport in a quasi-two-dimensional δ-doped semiconductor system Type A1 Journal article
Year 1996 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 80 Issue Pages (down) 5809-5814
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The effects due to intersubband coupling and screening on the ionized impurity scattering are studied for a quasi-two-dimensional electron system in delta-doped semiconductors. We found that intersubband coupling plays an essential role in describing the screening properties and the effect of ionized impurity scattering on the mobility in a multisubband system. At the onset of the occupation of a higher subband, the screening due to the intersubband coupling leads to a reduction of the small angle scattering rate in the lower subband. We showed that such an effect is significant in a delta-doped quantum well and results in a pronounced increase of the quantum mobility at the onset of the occupation of a higher subband. (C) 1996 American Institute of Physics.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos A1996VU98700039 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.183 Times cited 40 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:15789 Serial 1712
Permanent link to this record
 
 
Author Shi, J.M.; Peeters, F.M.; Hai, G.Q.; Devreese, J.T.
Title Donor transition energy in GaAs-superlattices in a magnetic field along the growth axis Type A1 Journal article
Year 1991 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 44 Issue Pages (down) 5692-5702
Keywords A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1991GF44300042 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 0163-1829 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.736 Times cited 78 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:915 Serial 749
Permanent link to this record
 
 
Author Morozov, V.; Deyneko, D.; Basoyich, O.; Khaikina, E.G.; Spassky, D.; Morozov, A.; Chernyshev, V.; Abakumov, A.; Hadermann, J.
Title Incommensurately modulated structures and luminescence properties of the AgxSm(2-x)/3WO4 (x=0.286, 0.2) scheelites as thermographic phosphors Type A1 Journal article
Year 2018 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 30 Issue 14 Pages (down) 4788-4798
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ag+ for Sm3+ substitution in the scheelite-type AgxSm(2-x)/3 square(1-2x)/3WO4 tungstates has been investigated for its influence on the cation-vacancy ordering and luminescence properties. A solid state method was used to synthesize the x = 0.286 and x = 0.2 compounds, which exhibited (3 + 1)D incommensurately modulated structures in the transmission electron microscopy study. Their structures were refined using high resolution synchrotron powder X-ray diffraction data. Under near-ultraviolet light, both compounds show the characteristic emission lines for (4)G(5/2) -> H-6(J) (J = 5/2, 7/2, 9/2, and 11/2) transitions of the Sm3+ ions in the range 550-720 nm, with the J = 9/2 transition at the similar to 648 nm region being dominant for all photoluminescence spectra. The intensities of the (4)G(5/2) -> H-6(9/2) and (4)G(5/2) -> H-6(7/2) bands have different temperature dependencies. The emission intensity ratios (R) for these bands vary reproducibly with temperature, allowing the use of these materials as thermographic phosphors.
Address
Corporate Author Thesis
Publisher American Chemical Society Place of Publication Washington, D.C Editor
Language Wos 000440105500037 Publication Date 2018-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 2 Open Access Not_Open_Access
Notes ; This research was supported by FWO (Project G039211N), Flanders Research Foundation. The research was carried out within the state assignment of FASO of Russia (Themes No. 0339-2016-0007). V.M. thanks the Russian Foundation for Basic Research (Grant 18-03-00611) for financial support. E.G.K. and O.B. acknowledge financial support from the Russian Foundation for Basic Research (Grant 16-03-00510). D.D. thanks the Foundation of the Russian Federation President (Grant MK-3502.2018.5) for financial support. We are grateful to the ESRF for granting the beamtime. V.C. is grateful for the financial support of the Russian Ministry of Science and Education (Project No. RFMEFI61616X0069). We are grateful to the ESRF for the access to ID22 station (experiment MA-3313). ; Approved Most recent IF: 9.466
Call Number UA @ lucian @ c:irua:153156 Serial 5107
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Author Su, Y.; Prestat, E.; Hu, C.; Puthiyapura, V.K.; Neek-Amal, M.; Xiao, H.; Huang, K.; Kravets, V.G.; Haigh, S.J.; Hardacre, C.; Peeters, F.M.; Nair, R.R.
Title Self-limiting growth of two-dimensional palladium between graphene oxide layers Type A1 Journal article
Year 2019 Publication Nano letters Abbreviated Journal Nano Lett
Volume 19 Issue 7 Pages (down) 4678-4683
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The ability of different materials to display self-limiting growth has recently attracted an enormous amount of attention because of the importance of nanoscale materials in applications for catalysis, energy conversion, (opto)-electronics, and so forth. Here, we show that the electrochemical deposition of palladium (Pd) between graphene oxide (GO) sheets result in the self-limiting growth of 5-nm-thick Pd nanosheets. The self-limiting growth is found to be a consequence of the strong interaction of Pd with the confining GO sheets, which results in the bulk growth of Pd being energetically unfavorable for larger thicknesses. Furthermore, we have successfully carried out liquid exfoliation of the resulting Pd-GO laminates to isolate Pd nanosheets and have demonstrated their high efficiency in continuous flow catalysis and electrocatalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000475533900060 Publication Date 2019-06-07
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 17 Open Access
Notes ; This work was supported by the Royal Society, Engineering and Physical Sciences Research Council, U.K. (EP/S019367/1, EP/P025021/1, EP/K016946/1, and EP/ P009050/1), Graphene Flagship, and European Research Council (contract 679689 and EvoluTEM). We thank Dr. Sheng Zheng and Dr. K. S. Vasu at the University of Manchester for assisting us with sample preparation and characterization. The authors acknowledge the use of the facilities at the Henry Royce Institute for Advanced Materials and associated support services. V.K.P. and C.H. are grateful for the resources and support provided via membership in the UK Catalysis Hub Consortium and funding by EPSRC (Portfolio grants EP/K014706/2, EP/K014668/1, EP/K014854/1, EP/K014714/1, and EP/I019693/1). F.M.P. and M.N.-A. acknowledge the support from the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 12.712
Call Number UA @ admin @ c:irua:161245 Serial 5426
Permanent link to this record
 
 
Author Hai, G.Q.; Peeters, F.M.; Devreese, J.T.
Title Electron optical-phonon coupling in GaAs/AlxGa1-xAs quantum wells due to interface, slab and half-space modes Type A1 Journal article
Year 1993 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 48 Issue 7 Pages (down) 4666-4674
Keywords A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos A1993LW02600057 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.736 Times cited 102 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:5748 Serial 981
Permanent link to this record
 
 
Author Zhou, Z.; Tan, Y.; Yang, Q.; Bera, A.; Xiong, Z.; Yagmurcukardes, M.; Kim, M.; Zou, Y.; Wang, G.; Mishchenko, A.; Timokhin, I.; Wang, C.; Wang, H.; Yang, C.; Lu, Y.; Boya, R.; Liao, H.; Haigh, S.; Liu, H.; Peeters, F.M.; Li, Y.; Geim, A.K.; Hu, S.
Title Gas permeation through graphdiyne-based nanoporous membranes Type A1 Journal article
Year 2022 Publication Nature communications Abbreviated Journal Nat Commun
Volume 13 Issue 1 Pages (down) 4031-4036
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of similar to 0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000918423100001 Publication Date 2022-07-12
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 21 Open Access OpenAccess
Notes Approved Most recent IF: 16.6
Call Number UA @ admin @ c:irua:194402 Serial 7308
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Author Jacquet, S.H.M.; Henjes, J.; Dehairs, F.; Worobiec, A.; Savoye, N.; Cardinal, D.
Title Particulate ba-barite and acantharians in the Southern Ocean during the European iron fertilization experiment (EIFEX) Type A1 Journal article
Year 2007 Publication Journal of geophysical research: G: biogeosciences Abbreviated Journal
Volume 112 Issue 4 Pages (down) 04006,1-11
Keywords A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000250522300001 Publication Date 2007-10-22
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
Notes Approved no
Call Number UA @ admin @ c:irua:66683 Serial 8359
Permanent link to this record
 
 
Author Shi, J.M.; Peeters, F.M.; Farias, G.A.; Freire, J.A.K.; Hai, G.Q.; Devreese, J.T.; Bednarek, S.; Adamowski, J.
Title Polaron effect on D- centers in weakly polar semiconductors Type A1 Journal article
Year 1998 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 57 Issue Pages (down) 3900-3904
Keywords A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000072163300041 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 28 Open Access
Notes Approved Most recent IF: 3.836; 1998 IF: NA
Call Number UA @ lucian @ c:irua:21907 Serial 2665
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Author Bekaert, J.; Khestanova, E.; Hopkinson, D.G.; Birkbeck, J.; Clark, N.; Zhu, M.; Bandurin, D.A.; Gorbachev, R.; Fairclough, S.; Zou, Y.; Hamer, M.; Terry, D.J.; Peters, J.J.P.; Sanchez, A.M.; Partoens, B.; Haigh, S.J.; Milošević, M.V.; Grigorieva, I., V
Title Enhanced superconductivity in few-layer TaS₂ due to healing by oxygenation Type A1 Journal article
Year 2020 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 20 Issue 5 Pages (down) 3808-3818
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract When approaching the atomically thin limit, defects and disorder play an increasingly important role in the properties of two-dimensional (2D) materials. While defects are generally thought to negatively affect superconductivity in 2D materials, here we demonstrate the contrary in the case of oxygenation of ultrathin tantalum disulfide (TaS2). Our first-principles calculations show that incorporation of oxygen into the TaS2 crystal lattice is energetically favorable and effectively heals sulfur vacancies typically present in these crystals, thus restoring the electronic band structure and the carrier density to the intrinsic characteristics of TaS2. Strikingly, this leads to a strong enhancement of the electron-phonon coupling, by up to 80% in the highly oxygenated limit. Using transport measurements on fresh and aged (oxygenated) few-layer TaS2, we found a marked increase of the superconducting critical temperature (T-c) upon aging, in agreement with our theory, while concurrent electron microscopy and electron-energy loss spectroscopy confirmed the presence of sulfur vacancies in freshly prepared TaS2 and incorporation of oxygen into the crystal lattice with time. Our work thus reveals the mechanism by which certain atomic-scale defects can be beneficial to superconductivity and opens a new route to engineer T-c in ultrathin materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535255300114 Publication Date 2020-04-20
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 10.8 Times cited 16 Open Access
Notes ; This work was supported by Research Foundation-Flanders (FWO). J.Be. acknowledges support of a postdoctoral fellowship of the FWO. The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. S.J.H., D.H., and S.F. would like to thank the Engineering and Physical Sciences Research Council (EPSRC) U.K (grants EP/R031711/1, EP/P009050/1 and the Graphene NOWNANO CDT) and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement ERC-2016-STG-EvoluTEM-715502, the Hetero2D Synergy grant and EC-FET Graphene Flagship) for funding. We thank Diamond Light Source for access and support in use of the electron Physical Science Imaging Centre (Instrument E02 and proposal numbers EM19315 and MG21597) that contributed to the results presented here. ; Approved Most recent IF: 10.8; 2020 IF: 12.712
Call Number UA @ admin @ c:irua:170264 Serial 6507
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Author Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Wu, X.G.; Eustis, T.J.; Schaff, W.
Title Resonant magnetopolaron effects due to interface phonons in GaAs/AlGaAs multiple quantum well structures Type A1 Journal article
Year 1997 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 79 Issue Pages (down) 3226-3229
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos A1997YC78200033 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 36 Open Access
Notes Approved Most recent IF: 8.462; 1997 IF: 6.140
Call Number UA @ lucian @ c:irua:19278 Serial 2889
Permanent link to this record
 
 
Author Teodorescu, V.S.; Mihailescu, I.N.; Gyorgy, E.; Luches, A.; Martino, M.; Nistor, L.C.; van Landuyt, J.; Hermann, J.
Title The study of a crater forming on the surface of a Ti target submitted to multipulse excimer laser irradiation under low pressure N2 Type A1 Journal article
Year 1996 Publication Journal of modern optics Abbreviated Journal J Mod Optic
Volume 43 Issue 9 Pages (down) 1773-1784
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A Ti target was submitted to laser ablation in low ambient pressure N-2. Electron microscopy examination of the cross-section of the crater zone forming on the Ti target, and XPS analyses, indicate that there is a small effect on the nitridation processes taking place on and in the vicinity of the target. The studies show a zone influenced by the multipulse laser treatment extending beneath the crater down to a depth of the same order of magnitude as the crater depth (i.e. similar to 10 mu m). In this zone, TiN could be identified as being present only in traces, while the whole zone exhibited a layer structure with differences in morphology and mechanical wear.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos A1996VF31900002 Publication Date 2007-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0950-0340;1362-3044; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.008 Times cited 11 Open Access
Notes Approved PHYSICS, APPLIED 47/145 Q2 #
Call Number UA @ lucian @ c:irua:95238 Serial 3594
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Author Zou, Y.-C.; Mogg, L.; Clark, N.; Bacaksiz, C.; Milanovic, S.; Sreepal, V.; Hao, G.-P.; Wang, Y.-C.; Hopkinson, D.G.; Gorbachev, R.; Shaw, S.; Novoselov, K.S.; Raveendran-Nair, R.; Peeters, F.M.; Lozada-Hidalgo, M.; Haigh, S.J.
Title Ion exchange in atomically thin clays and micas Type A1 Journal article
Year 2021 Publication Nature Materials Abbreviated Journal Nat Mater
Volume 20 Issue 12 Pages (down) 1677-1682
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The physical properties of clays and micas can be controlled by exchanging ions in the crystal lattice. Atomically thin materials can have superior properties in a range of membrane applications, yet the ion-exchange process itself remains largely unexplored in few-layer crystals. Here we use atomic-resolution scanning transmission electron microscopy to study the dynamics of ion exchange and reveal individual ion binding sites in atomically thin and artificially restacked clays and micas. We find that the ion diffusion coefficient for the interlayer space of atomically thin samples is up to 10(4) times larger than in bulk crystals and approaches its value in free water. Samples where no bulk exchange is expected display fast exchange at restacked interfaces, where the exchanged ions arrange in islands with dimensions controlled by the moire superlattice dimensions. We attribute the fast ion diffusion to enhanced interlayer expandability resulting from weaker interlayer binding forces in both atomically thin and restacked materials. This work provides atomic scale insights into ion diffusion in highly confined spaces and suggests strategies to design exfoliated clay membranes with enhanced performance. Layered clays are of interest for membranes and many other applications but their ion-exchange dynamics remain unexplored in atomically thin materials. Here, using electron microscopy, it is found that the ion diffusion for few-layer two-dimensional clays approaches that of free water and that superlattice cation islands can form in twisted and restacked materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000689664000001 Publication Date 2021-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122; 1476-4660 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 39.737
Call Number UA @ admin @ c:irua:181691 Serial 6999
Permanent link to this record
 
 
Author Mikhailova, D.; Kuratieva, N.N.; Utsumi, Y.; Tsirlin, A.A.; Abakumov, A.M.; Schmidt, M.; Oswald, S.; Fuess, H.; Ehrenberg, H.
Title Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution Type A1 Journal article
Year 2017 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal
Volume 46 Issue 5 Pages (down) 1606-1617
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The substitution of vanadium in vanadium dioxide VO2 influences the critical temperatures of structural and metal-to-insulator transitions in different ways depending on the valence of the dopant. Rhenium adopts valence states between + 4 and + 7 in an octahedral oxygen surrounding and is particularly interesting in this context. Structural investigation of V1-xRexO2 solid solutions (0.01 <= x <= 0.30) between 80 and 1200 K using synchrotron X-ray powder diffraction revealed only two polymorphs that resemble VO2: the low-temperature monoclinic MoO2-type form (space group P2(1)/c), and the tetragonal rutile-like form (space group P4(2)/mnm). However, for compositions with 0.03 < x <= 0.15 a phase separation in the solid solution was observed below 1000 K upon cooling down from 1200 K, giving rise to two isostructural phases with slightly different lattice parameters. This is reflected in the appearance of two metal-toinsulator transition temperatures detected by magnetization and specific heat measurements. Comprehensive X-ray photoelectron spectroscopy studies showed that an increased amount of Re leads to a change in the Re valence state from solely Re6+ at a low doping level (<= 3 at% Re) via mixed-valence states Re4+/Re6+ for at least 0.03 < x <= 0.10, up to nearly pure Re4+ in V0.70Re0.30O2. Thus, compositions V1-xRexO2 with only one valence state of Re in the material (Re6+ or Re4+) can be obtained as a single phase, while intermediate compositions are subjected to a phase separation, presumably due to different valence states of Re.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000395442700030 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0300-9246; 1477-9226; 1472-7773 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.029 Times cited 1 Open Access Not_Open_Access
Notes ; The authors are indebted to Dr G. Auffermann (Max Planck Institute for Chemical Physics of Solids, Dresden, Germany) for performing the ICP-OES analyses. This research has received a partial funding from the BMBF, project grant number 03SF0477B (DESIREE). AT acknowledges financial support from Federal Ministry for Education and Research under Sofja Kovalevksaya Award of Alexander von Humboldt Foundation. AMA is grateful to the Russian Science Foundation (grant 14-13-00680) for financial support. ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:142580 Serial 4642
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Author Lueangchaichaweng, W.; Brooks, N.R.; Fiorilli, S.; Gobechiya, E.; Lin, K.; Li, L.; Parres-Esclapez, S.; Javon, E.; Bals, S.; Van Tendeloo, G.; Martens, J.A.; Kirschhock, C.E.A.; Jacobs, P.A.; Pescarmona, P.P.;
Title Gallium oxide nanorods : novel, template-free synthesis and high catalytic activity in epoxidation reactions Type A1 Journal article
Year 2014 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit
Volume 53 Issue 6 Pages (down) 1585-1589
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Gallium oxide nanorods with unprecedented small dimensions (20-80nm length and 3-5nm width) were prepared using a novel, template-free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H2O2, rivaling the industrial benchmark microporous titanosilicate TS-1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000330558400021 Publication Date 2014-01-22
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 61 Open Access OpenAccess
Notes START 1; Methusalem; Prodex; IAP-PAI; and the ERC (grant number 24691-COUNTATOMS and grant number 335078-COLOURATOM) projects; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 11.994; 2014 IF: 11.261
Call Number UA @ lucian @ c:irua:115726 Serial 1314
Permanent link to this record
 
 
Author Radaelli, P.G.; Marezio, M.; Tholence, J.L.; de Brion, S.; Santoro, A.; Huang, Q.; Capponi, J.J.; Chaillout, C.; Krekels, T.; Van Tendeloo, G.
Title Crystal structure of the double Hg-layer copper oxide superconductor (Hg, Pr)2Ba2(Y, Ca)Cu2O8-\delta as a function of doping Type A1 Journal article
Year 1995 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids
Volume 56 Issue 10 Pages (down) 1471-1478
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos A1995RR95600025 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.853 Times cited 16 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:13323 Serial 573
Permanent link to this record
 
 
Author Radaelli, P.G.; Marezio, M.; Tholence, J.L.; Debrion, S.; Santoro, A.; Huang, Q.; Capponi, J.J.; Chaillout, C.; Krekels, T.; Van Tendeloo, G.
Title Crystal-structure of the double-hg-layer copper-oxide superconductor (Hg,Pr)2Ba2(Y,Ca)Cu2O8-\deltaas a function of doping Type A1 Journal article
Year 1995 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids
Volume 56 Issue 10 Pages (down) 1471-1478
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The crystal structure of the newly discovered double-Hg-layer copper oxide superconductor (Hg, Pr)(2)Ba-2(Y, Ca)Cu2O8-delta was studied as a function of chemical doping using neutron and electron diffraction and high-resolution transmission electron microscopy (HREM). Rietveld refinements of the structural parameters from neutron powder diffraction data indicate that the oxygen site O3 on the mercury plane is highly defective, being both partially occupied and displaced from the high-symmetry position. The variable concentration of oxygen vacancies partially compensates for the cation doping and, together with the O3 displacement field, makes some of the Hg atoms acquire an unusual pyramidal coordination. HREM images confirm that the structure is of the '2212' type, with very few defects. In some grains, faint superstructure reflections were evidenced by electron diffraction, suggesting that both the oxygen vacancies and the O3 displacement field may order at least on a local scale.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos A1995RR95600025 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3697; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.853 Times cited 16 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:104423 Serial 574
Permanent link to this record