Records |
Author |
Amin-Ahmadi, B.; Aashuri, H. |
Title |
Globular structure of M2 high speed steel by thermomechanical treatment in the semisolid state |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Steel research international |
Abbreviated Journal |
Steel Res Int |
Volume |
81 |
Issue |
5 |
Pages |
381-386 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The globular structure of M2 high speed steel in the rolled – annealed and as cast conditions was investigated in the semisolid state. Metallographic observations resulted in globular austenite particles that were surrounded by a liquid phase. Dissolution of various carbides in the austenite phase at semisolid temperatures led to grain boundary liquation and formation of near-spherical solid grains in a liquid matrix. Therefore, at the semisolid state, the solid particles were free from carbides. MC- type and M6C- type eutectic carbides re- precipitated at the grain boundaries during cooling of the samples from the semisolid temperature. The variation of shape factor versus holding time and holding temperature was examined. A transition value for shape factor changes in high speed steels was achieved. The growth rate constants of the Ostwald ripening and the coalescence mechanisms were calculated by using the experimentally determined rate constant. It was observed that less liquid droplets were enclosed inside the solid particles compared with non-ferrous alloys. Besides, it has been shown that at high solid fraction, the Ostwald ripening mechanism plays a prominent role in the coarsening phenomenon in comparison with the coalescence mechanism. Grains can rotate and arrange low misorientation with each other at high liquid contents, therefore low energetic grain boundaries form between these grains. These grain boundaries play an important role in the coalescence mechanism. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Verlag Stahleisen |
Place of Publication |
Düsseldorf |
Editor |
|
Language |
|
Wos |
000278292200007 |
Publication Date |
2010-05-18 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1611-3683;1869-344X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.235 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.235; 2010 IF: 0.455 |
Call Number |
UA @ lucian @ c:irua:122047 |
Serial |
1347 |
Permanent link to this record |
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|
Author |
Ludu, A.; Milošević, M.V.; Peeters, F.M. |
Title |
Vortex states in axially symmetric superconductors in applied magnetic field |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Sn – 0378-4754 |
Abbreviated Journal |
Math Comput Simulat |
Volume |
82 |
Issue |
7 |
Pages |
1258-1270 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We solve analytically the linearized Ginzburg-Landau (GL) equation in the presence of an uniform magnetic field with cylindrical boundary conditions. The solution of the non-linear GL equation is provided as an expansion in the basis of linearized solutions. We present examples of the resulting vortex structure for a solid and perforated superconducting cylinder. (C) 2012 IMACS. Published by Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000303097000009 |
Publication Date |
2012-02-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0378-4754; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.218 |
Times cited |
1 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 1.218; 2012 IF: 0.836 |
Call Number |
UA @ lucian @ c:irua:98300 |
Serial |
3887 |
Permanent link to this record |
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Author |
Kovba, M.L.; Skolis, Y.Y.; Abakumov, A.M.; Hadermann, J.; Sukhushina, I.S. |
Title |
The synthesis and thermodynamic properties of strontium fluoromanganite Sr2.5Mn6O12.5-\deltaF2 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Russian journal of physical chemistry A |
Abbreviated Journal |
Russ J Phys Chem A+ |
Volume |
84 |
Issue |
12 |
Pages |
2033-2038 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The existence of the [SrF(0.8)O(0.1)](2.5)[Mn(6)O(12)] = Sr(2.5)Mn(6)O(12.5 – delta)F(2) compound was established in the SrO-Mn(2)O(3)-SrF(2) system at 900A degrees C and p(O(2)) = 1 atm. The crystal structure of strontium fluoromanganite was determined from the X-ray powder diffraction data, electron diffraction, and high-resolution electron microscopy. It can be described in the monoclynic system with four Miller hklm indices: hklm: H = h a* + k b* + l c (1) (*) + m q (1), q (1), q (1) = c (2) (*) = gamma c (1) (*) , gamma a parts per thousand 0.632, a a parts per thousand a a parts per thousand 9.72 , b a parts per thousand 9.55 , c (1) a parts per thousand 2.84 , c (2) a parts per thousand 4.49 , monoclinic angle gamma a parts per thousand 95.6A degrees. The electromotive force method with a solid fluorine ion electrolyte was used to refine the composition of fluoromanganite and determine the thermodynamic functions of its formation from phases neighboring in the phase diagram (SrMn(3)O(6), Mn(2)O(3), SrF(2), and oxygen), Delta GA degrees, kJ/mol = -(111.7 +/- 1.9) + (89.5 +/- 1.5) x 10(-3) T. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000284775000004 |
Publication Date |
2011-02-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0036-0244;1531-863X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.581 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.581; 2010 IF: 0.503 |
Call Number |
UA @ lucian @ c:irua:99190 |
Serial |
3601 |
Permanent link to this record |
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|
|
Author |
Saniz, R.; Partoens, B.; Peeters, F.M. |
Title |
Green function approach to superconductivity in nanowires |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
14 |
Pages |
144504-144504,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Superconductivity in nanowires made of weak coupling superconductor materials is investigated using a Green function approach. We show that these are multigap systems in which the ratio Delta(T)/k(B)T(c) is to a large extent similar to what is observed in some high-T-c two-gap systems, such as MgB2 and some of the Fe-based superconductors. On the other hand, because of confinement, the superfluid density has a temperature behavior of the form n(s)(T) = 1 – (T/T-c)(3) near T-c, thus deviating from the BCS behavior for bulk superconductors. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000302290700006 |
Publication Date |
2012-04-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
1 |
Open Access |
|
Notes |
; This work was supported by FWO-Vl and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:97764 |
Serial |
1381 |
Permanent link to this record |
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|
|
Author |
Theuns, T.; Michel, K.H. |
Title |
Free energy and structural phase transitions in mixed crystals: a microscopic derivation |
Type |
A1 Journal article |
Year |
1992 |
Publication |
Zeitschrift für Physik: B |
Abbreviated Journal |
|
Volume |
86 |
Issue |
|
Pages |
125-131 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
A1992GV45100019 |
Publication Date |
2005-03-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0722-3277;1434-6036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:44748 |
Serial |
1276 |
Permanent link to this record |
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Author |
Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M. |
Title |
Effect of a perpendicular magnetic field on the shallow donor states near a semiconductor-metal interface |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
87 |
Issue |
7 |
Pages |
075313-75319 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate the influence of an external perpendicular magnetic field on the lowest-energy states of an electron bound to a donor which is located near a semiconductor-metal interface. The problem is treated within the effective mass approach and the lowest-energy states are obtained through (1) the “numerically exact” finite element method, and (2) a variational approach using a trial wave function where all image charges that emerge due to the presence of the metallic gate are taken into account. The trial wave functions are constructed such that they reduce to an exponential behavior for sufficiently small magnetic fields and become Gaussian for intermediate and large magnetic fields. The average electron-donor distance can be controlled by the external magnetic field. We find that the size of the 2p(z) state depends strongly on the magnetic field when the donor is close to the interface, showing a nonmonotonic behavior, in contrast with the ground and the other excited states. DOI: 10.1103/PhysRevB.87.075313 |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000314874800017 |
Publication Date |
2013-02-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
1 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
Call Number |
UA @ lucian @ c:irua:107664 |
Serial |
793 |
Permanent link to this record |
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|
Author |
Rossi, E.H.M.; Van Tendeloo, G.; Rosenauer, A. |
Title |
Influence of strain, specimen orientation and background estimation on composition evaluation of InAs/GaAs by TEM |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
Volume |
87 |
Issue |
29 |
Pages |
4461-4473 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
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Wos |
000249890700003 |
Publication Date |
2007-09-04 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1478-6435;1478-6443; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.505 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.505; 2007 IF: 1.486 |
Call Number |
UA @ lucian @ c:irua:66612 |
Serial |
1638 |
Permanent link to this record |
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Author |
Rozova, M.G.; Grigoriev, V.V.; Tyablikov, O.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Antipov, E.V.; Abakumov, A.M. |
Title |
Doping of Bi4Fe5O13F with pentagonal Cairo lattice with Cr and Mn: Synthesis, structure and magnetic properties |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Materials research bulletin |
Abbreviated Journal |
Mater Res Bull |
Volume |
87 |
Issue |
87 |
Pages |
54-60 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The substitution of Cr3+ and Mn3+ for Fe3+ in the Bi4Fe6O13F oxyfluoride featuring the magnetically frustrated pentagonal Cairo lattice is reported. Bi4Fe4.1Cr0.9O13F and BiFe4.2Mn0.8O13F have been prepared using a solid state reaction in inert atmosphere. Their crystal structures were studied with transmission electron microscopy, powder X-ray diffraction and Fe-57 Mossbauer spectroscopy (S.G. P4(2)/mbc, a = 8.27836(2)angstrom, c = 18.00330(9) angstrom, R-F = 0.031 (Bi4Fe4.1Cr0.9O13F)), a= 8.29535(3)angstrom, c= 18.0060(1)angstrom, R-F = 0.027 (Bi4Fe4.1Cr0.9O13F)). The structures are formed by infinite rutile-like chains of the edge sharing BO6 octahedra (B transition metal cations) linked by the Fe2O7 groups of two corner-sharing tetrahedra. The"voids in thus formed framework are occupied by the Bi4F tetrahedra. The Fe-57 Mossbauer spectroscopy reveals that Cr3+ and Mn3+ replace Fe3+. exclusively at the octahedral positions. The Mn- and Cr-doped compounds demonstrate antiferromagnetic ordering below T-N =165 K and 120 K, respectively. (C) 2016 Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000392681800009 |
Publication Date |
2016-11-17 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0025-5408 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.446 |
Times cited |
1 |
Open Access |
Not_Open_Access |
Notes |
; The work has been supported by the Russian Science Foundation (grant 14-13-00680). ; |
Approved |
Most recent IF: 2.446 |
Call Number |
UA @ lucian @ c:irua:141535 |
Serial |
4498 |
Permanent link to this record |
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Author |
Admasu, W.F.; Van Passel, S.; Minale, A.S.; Tsegaye, E.A.; Azadi, H.; Nyssen, J. |
Title |
Take out the farmer: An economic assessment of land expropriation for urban expansion in Bahir Dar, Northwest Ethiopia |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Land Use Policy |
Abbreviated Journal |
Land Use Policy |
Volume |
87 |
Issue |
87 |
Pages |
104038 |
Keywords |
A1 Journal article; Engineering Management (ENM) |
Abstract |
In Ethiopia, the demand for land for urbanisation is primarily met by converting rural land through expropriation. However, land expropriations are adversely affecting the previous land users by reducing the amount of production and their sources of income. In Bahir Dar, one of the fastest-growing cities in Ethiopia, approximately 300 landholdings are expropriated each year, on average, for urban expansion. This paper assesses the land expropriations to examine whether they offer economically appropriate compensation for the previous land users. Land expropriations for urbanisation between 2007/2008 and 2016/2017 were analysed based on data on land expropriation and its compensation payment obtained from the Bahir Dar City Land Administration and Management Office. Data were analysed using an exponential growth model and a stochastic budgeting technique in which Monte Carlo simulations are performed. Between 2007/2008 and 2016/2017, more than 1500 ha of land were included in the city's boundary through expropriation from 2900 landholders. The affected farmers received compensation that represents only 37 per cent of the value of current crop yields and its growth. The current compensation scheme ignores the impact of inflation on the prices of crops and assumes constant yields. It also excludes the value of crop residuals. We propose a workable discounted compensation framework that considers crop price and yield growths. This will make the compensation scheme more appropriate and make the affected farmers better off. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000483419100026 |
Publication Date |
2019-06-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0264-8377 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
3.089 |
Times cited |
1 |
Open Access |
|
Notes |
; The authors acknowledge the Bahir Dar City Administration for sharing its compensation data, Bahir Dar Zuria Wereda Agriculture Office for sharing yield data, and the Industry and Trade Development Office for sharing crop price data. The Institutional University Cooperation with Bahir Dar University (BDU-IUC), funded by the Belgian authorities, through the Flemish Interuniversity Council University Development Cooperation, funded the research activities. We also thank the two anonymous reviewers and the editor of Land Use Policy for all constructive comments and suggestions. ; |
Approved |
Most recent IF: 3.089 |
Call Number |
UA @ admin @ c:irua:162837 |
Serial |
6261 |
Permanent link to this record |
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Author |
Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B. |
Title |
Erratum : First-principles study of possible shallow donors in ZnAl2O4 spinel [Phys. Rev. B 87, 174101 (2013)] |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
88 |
Issue |
5 |
Pages |
059905-2 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000323572600009 |
Publication Date |
2013-08-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
1 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
Call Number |
UA @ lucian @ c:irua:110015 |
Serial |
1080 |
Permanent link to this record |
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Author |
Bals, S.; Verbeeck, J.; Van Tendeloo, G.; Liu, Y.-L.; Grivel, J.-C. |
Title |
Quantitative electron microscopy of (Bi,Pb)2Sr2Ca2Cu3O10+\delta/Ag multifilament tapes during initial stages of annealing |
Type |
A1 Journal article |
Year |
2005 |
Publication |
Journal of the American Ceramic Society |
Abbreviated Journal |
J Am Ceram Soc |
Volume |
88 |
Issue |
2 |
Pages |
431-436 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The microstructural and compositional evolution during initial annealing of a superconducting (Bi,Pb)(2)Sr2Ca2Cu3O10+delta/Ag tape is studied using quantitative transmission electron microscopy. Special attention is devoted to the occurrence of Pb-rich liquids, which are crucial for the Bi2Sr2CaCu2O8+delta to (Bi,Pb)(2)Sr2Ca2Cu3O10+delta transformation. Ca and/or Pb-rich (Bi,Pb)(2)Sr2CaCu2O8+delta grains dissolve into a liquid, which reacts with Ca-rich phases to increase the liquid's Ca-content. This leads to (Bi,Pb)(2)Sr2Ca2Cu3O10+delta formation. Apparently, a Ca/Sr ratio of around I is sufficient to keep (Bi,Pb)(2)Sr2Ca2Cu3O10+delta nucleation going. It is confirmed that Ag particles are transported from the Ag-sheath into the oxide core by the liquid and not by mechanical treatment of the tape. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Columbus, Ohio |
Editor |
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Language |
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Wos |
000227510200030 |
Publication Date |
2005-02-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7820;1551-2916; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.841 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.841; 2005 IF: 1.586 |
Call Number |
UA @ lucian @ c:irua:54876UA @ admin @ c:irua:54876 |
Serial |
2754 |
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Savel'ev, S.; Kusmartsev, F.V.; Peeters, F.M. |
Title |
Effect of ordered array of magnetic dots on the dynamics of Josephson vortices in stacked SNS Josephson junctions under DC and AC current |
Type |
A1 Journal article |
Year |
2015 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
Volume |
88 |
Issue |
88 |
Pages |
286 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We use the anisotropic time-dependent Ginzburg-Landau theory to investigate the effect of a square array of out-of-plane magnetic dots on the dynamics of Josephson vortices (fluxons) in artificial stacks of superconducting-normal-superconducting (SNS) Josephson junctions in the presence of external DC and AC currents. Periodic pinning due to the magnetic dots distorts the triangular lattice of fluxons and results in the appearance of commensurability features in the current-voltage characteristics of the system. For the larger values of the magnetization, additional peaks appear in the voltage-time characteristics of the system due to the creation and annihilation of vortex-antivortex pairs. Peculiar changes in the response of the system to the applied current is found resulting in a “superradiant” vortex-flow state at large current values, where a rectangular lattice of moving vortices is formed. Synchronizing the motion of fluxons by adding a small ac component to the biasing dc current is realized. However, we found that synchronization becomes difficult for large magnetization of the dots due to the formation of vortex-antivortex pairs. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000363960900002 |
Publication Date |
2015-10-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1434-6028 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.461 |
Times cited |
1 |
Open Access |
|
Notes |
; This work was supported by EU Marie Curie (Project No. 253057). ; |
Approved |
Most recent IF: 1.461; 2015 IF: 1.345 |
Call Number |
UA @ lucian @ c:irua:129509 |
Serial |
4166 |
Permanent link to this record |
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Author |
Klimin, S.N.; Tempère, J.; Misko, V.R.; Wouters, M. |
Title |
Finite-temperature Wigner solid and other phases of ripplonic polarons on a helium film |
Type |
A1 Journal article |
Year |
2016 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
Volume |
89 |
Issue |
89 |
Pages |
172 |
Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
Abstract |
Electrons on liquid helium can form different phases depending on density, and temperature. Also the electron-ripplon coupling strength influences the phase diagram, through the formation of so-called “ripplonic polarons”, that change how electrons are localized, and that shifts the transition between the Wigner solid and the liquid phase. We use an all-coupling, finite-temperature variational method to study the formation of a ripplopolaron Wigner solid on a liquid helium film for different regimes of the electron-ripplon coupling strength. In addition to the three known phases of the ripplopolaron system (electron Wigner solid, polaron Wigner solid, and electron fluid), we define and identify a fourth distinct phase, the ripplopolaron liquid. We analyse the transitions between these four phases and calculate the corresponding phase diagrams. This reveals a reentrant melting of the electron solid as a function of temperature. The calculated regions of existence of the Wigner solid are in agreement with recent experimental data. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
|
Language |
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Wos |
000391225200001 |
Publication Date |
2016-07-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1434-6028 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.461 |
Times cited |
1 |
Open Access |
|
Notes |
; We thank A.S. Mishchenko and D.G. Rees for valuable discussions. This research has been supported by the Flemish Research Foundation (FWO-Vl), Project Nos. G.0115.12N, G.0119.12N, G.0122.12N, G.0429.15N, by the Scientific Research Network of the Research Foundation-Flanders, WO.033.09N, and by the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 1.461 |
Call Number |
UA @ lucian @ c:irua:140351 |
Serial |
4454 |
Permanent link to this record |
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|
Author |
Apolinario, S.W.S.; Aguiar, J.A.; Peeters, F.M. |
Title |
Angular melting scenarios in binary dusty-plasma Coulomb balls : magic versus normal clusters |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
90 |
Issue |
6 |
Pages |
063113 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Molecular-dynamic simulations were performed in order to investigate the melting processes of isotropically confined binary systems. We considered two species of particles, which differ by their amount of electric charge. A Lindemann type of criterion was used to determine the angular melting temperature. We demonstrate that the magic-to-normal cluster transition can evolve in two distinct ways, that is, through a structural phase transition of the first order or via a smooth transition where an increase of the shells' width leads to a continuous decreasing mechanical stability of the system. Moreover, for large systems, we demonstrate that the internal cluster exerts a minor effect on the mechanical stability of the external shell. Furthermore, we show that highly symmetric configurations, such as those found for multiple ring structures, have large mechanical stability, i.e., high angular melting temperature. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000347207000027 |
Publication Date |
2014-12-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
1 |
Open Access |
|
Notes |
; This work was supported by FACEPE (Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco) Grant No. APQ-1800-1.05/ 12, the bilatera project between CNPq and FWO-VL, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 2.366; 2014 IF: 2.288 |
Call Number |
UA @ lucian @ c:irua:122828 |
Serial |
116 |
Permanent link to this record |
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|
|
Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
Title |
Reply to “Comment on 'Vortices induced in a superconducting loop by asymmetric kinetic inductance and their detection in transport measurements' ” |
Type |
Editorial |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
90 |
Issue |
5 |
Pages |
056502 |
Keywords |
Editorial; Condensed Matter Theory (CMT) |
Abstract |
Our calculations, within known limitations of Ginzburg-Landau theory, are fully correct and valid for transport phenomena in asymmetric mesoscopic superconductors, deep in the superconducting state. We deemed the experiments of Burlakov et al. [JETP Lett. 86, 517 (2007)] relevant and important to mention in the general context of our paper since the observed shifts in the oscillations of different quantities are qualitatively similar, even though those measurements are performed close to the superconducting-normal state transition in the so-called Little-Parks regime. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000341266400006 |
Publication Date |
2014-08-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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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 |
1 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
Call Number |
UA @ lucian @ c:irua:119256 |
Serial |
2876 |
Permanent link to this record |
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|
Author |
Du, G.H.; Van Tendeloo, G. |
Title |
Formation of Mn304/C core-shell nanowires and a new MN-O phase by electron beam irradiation |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Applied physics A : materials science & processing |
Abbreviated Journal |
Appl Phys A-Mater |
Volume |
91 |
Issue |
3 |
Pages |
393-395 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Heidelberg |
Editor |
|
Language |
|
Wos |
000255089300007 |
Publication Date |
2008-03-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-8396;1432-0630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.455 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.455; 2008 IF: 1.884 |
Call Number |
UA @ lucian @ c:irua:69128 |
Serial |
1262 |
Permanent link to this record |
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|
|
Author |
Gkanatsiou, A.; Lioutas, C.B.; Frangis, N.; Polychroniadis, E.K.; Prystawko, P.; Leszczynski, M.; Altantzis, T.; Van Tendeloo, G. |
Title |
Influence of 4H-SiC substrate miscut on the epitaxy and microstructure of AlGaN/GaN heterostructures |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Materials science in semiconductor processing |
Abbreviated Journal |
Mat Sci Semicon Proc |
Volume |
91 |
Issue |
|
Pages |
159-166 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
AlGaN/GaN heterostructures were grown on “on-axis” and 2° off (0001) 4H-SiC substrates by metalorganic vapor phase epitaxy (MOVPE). Structural characterization was performed by transmission electron microscopy. The dislocation density, being greater in the on-axis case, is gradually reduced in the GaN layer and is forming
dislocation loops in the lower region. Steps aligned along [11̅00] in the off-axis case give rise to simultaneous defect formation. In the on-axis case, an almost zero density of steps is observed, with the main origin of defects probably being the orientation mismatch at the grain boundaries between the small not fully coalesced AlN grains. V-shaped formations are observed in the AlN nucleation layer, but are more frequent in the off-axis case, probably enhanced by the presence of steps. These V-shaped formations are completely overgrown by the GaN layer, during the subsequent deposition, presenting AlGaN areas in the walls of the defect, indicating an interdiffusion between the layers. Finally, at the AlGaN/GaN heterostructure surface in the on-axis case, V-shapes are observed, with the AlN spacer and AlGaN (21% Al) thickness on relaxed GaN exceeding the critical thickness for relaxation. On the other hand, no relaxation in the form of V-shape creation is observed in the off-axis case, probably due to the smaller AlGaN thickness (less than 21% Al). The AlN spacer layer, grown in between the heterostructure, presents a uniform thickness and clear interfaces. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000454537700022 |
Publication Date |
2018-11-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1369-8001 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.359 |
Times cited |
1 |
Open Access |
Not_Open_Access |
Notes |
Funding: This work was supported by the IKY Fellowships of Excellence for Postgraduate Studies in Greece-SIEMENS Program; the Greek General Secretariat for Research and Technology, contract SAE 013/8–2009SE 01380012; and the JU ENIAC Project LAST POWER Large Area silicon carbide Substrates and heteroepitaxial GaN for POWER device applications [grant number 120218]. Also part of the research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). T.A. acknowledges financial support from the Research Foundation Flanders (FWO, Belgium) through a post-doctoral grant. |
Approved |
Most recent IF: 2.359 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156200 |
Serial |
5149 |
Permanent link to this record |
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Author |
Augustyns, V.; van Stiphout, K.; Joly, V.; Lima, T.A.L.; Lippertz, G.; Trekels, M.; Menendez, E.; Kremer, F.; Wahl, U.; Costa, A.R.G.; Correia, J.G.; Banerjee, D.; Gunnlaugsson, H.P.; von Bardeleben, J.; Vickridge, I.; Van Bael, M.J.; Hadermann, J.; Araujo, J.P.; Temst, K.; Vantomme, A.; Pereira, L.M.C. |
Title |
Evidence of tetragonal distortion as the origin of the ferromagnetic ground state in gamma-Fe nanoparticles |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
96 |
Issue |
17 |
Pages |
174410 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('gamma-Fe and related alloys are model systems of the coupling between structure and magnetism in solids. Since different electronic states (with different volumes and magnetic ordering states) are closely spaced in energy, small perturbations can alter which one is the actual ground state. Here, we demonstrate that the ferromagnetic state of gamma-Fe nanoparticles is associated with a tetragonal distortion of the fcc structure. Combining a wide range of complementary experimental techniques, including low-temperature Mossbauer spectroscopy, advanced transmission electron microscopy, and synchrotron radiation techniques, we unambiguously identify the tetragonally distorted ferromagnetic ground state, with lattice parameters a = 3.76(2) angstrom and c = 3.50(2) angstrom, and a magnetic moment of 2.45(5) mu(B) per Fe atom. Our findings indicate that the ferromagnetic order in nanostructured gamma-Fe is generally associated with a tetragonal distortion. This observation motivates a theoretical reassessment of the electronic structure of gamma-Fe taking tetragonal distortion into account.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000414525200005 |
Publication Date |
2017-11-07 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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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 |
1 |
Open Access |
OpenAccess |
Notes |
; The authors thank the Fund for Scientific Research-Flanders, the Concerted Research Action of the KU Leuven (GOA/14/007), the KU Leuven BOF (STRT/14/002), the Hercules Foundation, the Portuguese Foundation for Science and Technology (CERN/FIS-NUC/0004/2015), and the European Union Seventh Framework through ENSAR2 (European Nuclear Science and Applications Research, Project No. 654002), and SPIRIT (Support of Public and Industrial Research Using Ion Beam Technology, Contract No. 227012). We acknowledge the European Synchrotron Radiation Facility (ESRF) for providing beam time (experiments 26-01-1018, 26-01-1057, 20-02-728, HC-1850, HC-2208), as well as C. Baehtz, N. Boudet, and N. Blancand for support during the experiments. We acknowledge the ISOLDE-CERN facility for providing beam time (experiment IS580) and technical assistance. The authors (L.M.C.P., F.K.) acknowledge the facilities and the scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility at the Centre for Advanced Microscopy, Australian National University. We also acknowledge the contribution of Prof. Mark Ridgway (Australian National University), who passed away before the work was completed. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:147387 |
Serial |
4873 |
Permanent link to this record |
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Author |
Lebedev, O.I.; Bals, S.; Van Tendeloo, G.; Snoeck, G.E.; Retoux, R.; Boudin, S.; Hervieu, M. |
Title |
Mixed (Sr1-xCax)33Bi24Al48O141 fullerenoids: the defect structure analysed by (S)TEM techniques |
Type |
A1 Journal article |
Year |
2006 |
Publication |
International journal of materials research |
Abbreviated Journal |
Int J Mater Res |
Volume |
97 |
Issue |
7 |
Pages |
978-984 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
(Sr1-xCax)(33)Bi-24,partial derivative Al48O141+3 partial derivative/2 fullerenoid solid solutions have been synthesized and the effect of partial substitution of Sr by Ca has been characterized by (scanning) transmission electron microscopy, applying different imaging methods. Most of the defects commonly observed in face centered cubic compounds, have also been observed in (Sr1-xCax)(33)Bi24-partial derivative Al48O141+3 partial derivative/2. Based on purely geometrical and topological models, structural presentations for the coherent twin boundaries and stacking faults have been constructed on the basis of complex spherical “Al84O210” units. The results are compared to defects observed in the crystallite fullerite C-60. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000239916700017 |
Publication Date |
2013-12-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1862-5282;2195-8556; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.681 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.681; 2006 IF: NA |
Call Number |
UA @ lucian @ c:irua:60966 |
Serial |
2091 |
Permanent link to this record |
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Author |
Aierken, Y.; Leenaerts, O.; Peeters, F.M. |
Title |
First-principles study of the stability and edge stress of nitrogen-decorated graphene nanoribbons |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
97 |
Issue |
23 |
Pages |
235436 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Edge functionalization of graphene nanoribbons with nitrogen atoms for various adatom configurations at armchair and zigzag edges are investigated. We provide comprehensive information on the electronic and magnetic properties and investigate the stability of the various systems. Two types of rippling of the nanoribbons, namely edge and bulk rippling depending on the sign of edge stress induced at the edge, are found. They are found to play the decisive role for the stability of the structures. We also propose a type of edge decoration in which every third nitrogen adatom at the zigzag edges is replaced by an oxygen atom. In this way, the electron count is compatible with a full aromatic structure, leading to additional stability and a disappearance of magnetism that is usually associated with zigzag nanoribbons. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000436192300006 |
Publication Date |
2018-06-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
|
Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government – department EWI. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:152478UA @ admin @ c:irua:152478 |
Serial |
5104 |
Permanent link to this record |
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Author |
Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
Title |
Inelastic electron tunneling spectroscopy of HfO2 gate stacks : a study based on first-principles modeling |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
99 |
Issue |
13 |
Pages |
132101,1-132101,3 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A first-principles modeling approach is used to investigate the vibrational properties of HfO2. The calculated phonon density of states is compared to experimental results obtained from inelastic electron tunneling spectroscopy (IETS) of various metal-oxide-semiconductor devices with HfO2 gate stacks. This comparison provides deep insights into the nature of the signatures of the complicated IETS spectra and provides valuable structural information about the gate stack, such as the possible presence of oxygen vacancies in jet-vapour deposited HfO2. Important structural differences between the interface of atomic-layer or molecular-beam deposited HfO2 and the Si substrate are also revealed. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000295618000036 |
Publication Date |
2011-09-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
Call Number |
UA @ lucian @ c:irua:93611 |
Serial |
1606 |
Permanent link to this record |
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Author |
Vansant, P.; Smondyrev, M.A.; Peeters, F.M.; Devreese, J.T. |
Title |
Strong-coupling limit for one-dimensional polarons in a finite box |
Type |
A1 Journal article |
Year |
1996 |
Publication |
Zeitschrift für Physik: B: condensed matter and quanta |
Abbreviated Journal |
|
Volume |
99 |
Issue |
|
Pages |
345-351 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
A1996TW44800007 |
Publication Date |
2002-08-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0722-3277;1431-584X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
Call Number |
UA @ lucian @ c:irua:15035 |
Serial |
3180 |
Permanent link to this record |
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Author |
Lujan, G.S.; Sorée, B.; Magnus, W.; de Meyer, K. |
Title |
A method to calculate tunneling leakage currents in silicon inversion layers |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
100 |
Issue |
3 |
Pages |
033708,1-5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000239764100051 |
Publication Date |
2006-08-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0021-8979; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2006 IF: 2.316 |
Call Number |
UA @ lucian @ c:irua:60963 |
Serial |
2016 |
Permanent link to this record |
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Author |
Frabboni, S.; Grillo, V.; Gazzadi, G.C.; Balboni, R.; Trotta, R.; Polimeni, A.; Capizzi, M.; Martelli, F.; Rubini, S.; Guzzinati, G.; Glas, F.; |
Title |
Convergent beam electron-diffraction investigation of lattice mismatch and static disorder in GaAs/GaAs1-xNx intercalated GaAs/GaAs1-xNx:H heterostructures |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
101 |
Issue |
11 |
Pages |
111912-111914 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Hydrogen incorporation in diluted nitride semiconductors dramatically modifies the electronic and structural properties of the crystal through the creation of nitrogen-hydrogen complexes. We report a convergent beam electron-diffraction characterization of diluted nitride semiconductor-heterostructures patterned at a sub-micron scale and selectively exposed to hydrogen. We present a method to determine separately perpendicular mismatch and static disorder in pristine and hydrogenated heterostructures. The roles of chemical composition and strain on static disorder have been separately assessed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752464] |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000309329300033 |
Publication Date |
2012-09-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
Call Number |
UA @ lucian @ c:irua:102203 |
Serial |
511 |
Permanent link to this record |
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|
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Author |
Menezes, R.M.; de Souza Silva, C.C.; Milošević, M.V. |
Title |
Spin textures in chiral magnetic monolayers with suppressed nearest-neighbor exchange |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
101 |
Issue |
21 |
Pages |
214429-9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
High tunability of two-dimensional magnetic materials (by strain, gating, heterostructuring, or otherwise) provides unique conditions for studying versatile magnetic properties and controlling emergent magnetic phases. Expanding the scope of achievable magnetic phenomena in such materials is important for both fundamental and technological advances. Here we perform atomistic spin-dynamics simulations to explore the (chiral) magnetic phases of atomic monolayers in the limit of suppressed first-neighbors exchange interaction. We report the rich phase diagram of exotic magnetic configurations, obtained for both square and honeycomb lattice symmetries, comprising coexistence of ferromagnetic and antiferromagnetic spin cycloids, as well as multiple types of magnetic skyrmions. We perform a minimum-energy path analysis for the skyrmion collapse to evaluate the stability of such topological objects and reveal that magnetic monolayers could be good candidates to host the antiferromagnetic skyrmions that are experimentally evasive to date. |
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Wos |
000540910100002 |
Publication Date |
2020-06-18 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
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Notes |
; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and Brazilian Agencies FACEPE (under Grant No. APQ-0198-1.05/14), CAPES, and CNPq. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:170176 |
Serial |
6610 |
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Author |
Leishman, A.W.D.; Menezes, R.M.; Longbons, G.; Bauer, E.D.; Janoschek, M.; Honecker, D.; DeBeer-Schmitt, L.; White, J.S.; Sokolova, A.; Milošević, M.V.; Eskildsen, M.R. |
Title |
Topological energy barrier for skyrmion lattice formation in MnSi |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
102 |
Issue |
10 |
Pages |
104416-104419 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We report the direct measurement of the topological skyrmion energy barrier through a hysteresis of the skyrmion lattice in the chiral magnet MnSi. Measurements were made using small-angle neutron scattering with a custom-built resistive coil to allow for high-precision minor hysteresis loops. The experimental data were analyzed using an adapted Preisach model to quantify the energy barrier for skyrmion formation and corroborated by the minimum-energy path analysis based on atomistic spin simulations. We reveal that the skyrmion lattice in MnSi forms from the conical phase progressively in small domains, each of which consisting of hundreds of skyrmions, and with an activation barrier of several eV. |
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Wos |
000568994800005 |
Publication Date |
2020-09-14 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
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Notes |
; This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Award No. DE-SC0005051 (A.W.D.L., G.L., M.R.E.), the Research Foundation -Flanders (FWO-Vlaanderen) (R.M.M., M.V.M.), and Brazilian Agencies FACEPE, CAPES and CNPq (R.M.M.). M.J. was supported by the LANL Directed Research and Development (LDRD) program via the Directed Research (DR) project “A New Approach to Mesoscale Functionality: Emergent Tunable Superlattices (20150082DR).” E.D.B. was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under project “Quantum Fluctuations in Narrow-Band Systems.” A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Part of this work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. We acknowledge useful conversations with E. Louden, D. Green, and A. Francisco in preparation for these experiments, as well as the assistance of K. Avers, G. Taufer, M. Harrington, M. Bartkowiak, and C. Baldwin in completing them. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:171959 |
Serial |
6631 |
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Author |
Savchenko, T.M.; Buzzi, M.; Howald, L.; Ruta, S.; Vijayakumar, J.; Timm, M.; Bracher, D.; Saha, S.; Derlet, P.M.; Béché, A.; Verbeeck, J.; Chantrell, R.W.; Vaz, C.A.F.; Nolting, F.; Kleibert, A. |
Title |
Single femtosecond laser pulse excitation of individual cobalt nanoparticles |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
102 |
Issue |
20 |
Pages |
205418 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Laser-induced manipulation of magnetism at the nanoscale is a rapidly growing research topic with potential for applications in spintronics. In this work, we address the role of the scattering cross section, thermal effects, and laser fluence on the magnetic, structural, and chemical stability of individual magnetic nanoparticles excited by single femtosecond laser pulses. We find that the energy transfer from the fs laser pulse to the nanoparticles is limited by the Rayleigh scattering cross section, which in combination with the light absorption of the supporting substrate and protective layers determines the increase in the nanoparticle temperature. We investigate individual Co nanoparticles (8 to 20 nm in size) as a prototypical model system, using x-ray photoemission electron microscopy and scanning electron microscopy upon excitation with single femtosecond laser pulses of varying intensity and polarization. In agreement with calculations, we find no deterministic or stochastic reversal of the magnetization in the nanoparticles up to intensities where ultrafast demagnetization or all-optical switching is typically reported in thin films. Instead, at higher fluences, the laser pulse excitation leads to photo-chemical reactions of the nanoparticles with the protective layer, which results in an irreversible change in the magnetic properties. Based on our findings, we discuss the conditions required for achieving laser-induced switching in isolated nanomagnets. |
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Wos |
000589602000005 |
Publication Date |
2020-11-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
This work received funding by the Swiss National Foundation (SNF) (Grants No. 200021160186 and No. 2002153540), the Swiss Nanoscience Institute (SNI) (Grant No. SNI P1502), the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 737093 (FEMTOTERABYTE), and the COST Action CA17123 (MAGNETOFON). Part of this work was performed at the SIM beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. Part of the simulations were undertaken on the VIKING cluster, which is a high-performance compute facility provided by the University of York. We kindly acknowledge Anja Weber from PSI for preparation of substrates with marker structures. A.B. and Jo Verbeeck acknowledge funding through FWO Project No. G093417N (“Compressed sensing enabling low dose imaging in transmission electron microscopy”) from the Flanders Research Fund. Jo Verbeeck acknowledges funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717 – ESTEEM3. S.S. acknowledges ETH Zurich Post-Doctoral fellowship and Marie Curie actions for people COFUND program.; esteem3JRA; esteem3reported |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
EMAT @ emat @c:irua:174273 |
Serial |
6669 |
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Author |
Shekarforoush, S.; Jalali, H.; Yagmurcukardes, M.; Milošević, M.V.; Neek-Amal, M. |
Title |
Optoelectronic properties of confined water in angstrom-scale slits |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
102 |
Issue |
23 |
Pages |
235406 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The optoelectronic properties of confined water form one of the most active research areas in the past few years. Here we present the multiscale methodology to discern the out-of-plane electronic and dipolar dielectric constants (epsilon(el)(perpendicular to) and epsilon(diP)(perpendicular to)) of strongly confined water. We reveal that epsilon(perpendicular to el) and epsilon(diP)(perpendicular to) become comparable for water confined in angstrom-scale channels (with a height of less than 15 angstrom) within graphene (GE) and hexagonal boron nitride (hBN) bilayers. Channel height (h) associated with a minimum in both epsilon(e)(l)(perpendicular to) and epsilon(dip)(perpendicular to) is linked to the formation of the ordered structure of ice for h approximate to (7 -7.5) angstrom. The recently measured total dielectric constant epsilon(T)(perpendicular to) of nanoconfined water [L. Fumagalli et al., Science 360, 1339 (2018)] is corroborated by our results. Furthermore, we evaluate the contribution from the encapsulating membranes to the dielectric properties, as a function of the interlayer spacing, i.e., the height of the confining channel for water. Finally, we conduct analysis of the optical properties of both confined water and GE membranes, and show that the electron energy loss function of confined water strongly differs from that of bulk water. |
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Wos |
000595856100004 |
Publication Date |
2020-12-04 |
Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
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Notes |
; This work was supported by the Research Foundation – Flanders (FWO). M.Y. gratefully acknowledges his FWO postdoctoral mandate. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:175051 |
Serial |
6695 |
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Author |
Thomé, T.; Colaux, J.L.; Colomer, J.-F.; Bertoni, G.; Terwagne, G. |
Title |
Formation of carbon nitride nanospheres by ion implantation |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Materials chemistry and physics |
Abbreviated Journal |
Mater Chem Phys |
Volume |
103 |
Issue |
2-3 |
Pages |
290-294 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Carbon nitride nanospheres have been synthesized into copper by simultaneous high fluence (10(18) at. cm(-2)) implantations of C-12 and N-15 ions. The composition of the implanted region has been measured using C-12(d,p(0))C-13 and N-15(d,alpha(0))C-13 nuclear reactions induced by a 1.05 MeV deuteron beam. The C-12 and N-15 depth profiles are very close and the retained doses into copper are relatively high, which indicates that carbon and nitrogen diffusion processes are likely limited during implantation. High resolution transmission electron microscopy (HRTEM) observations and electron diffraction (ED) analyses have been carried out to determine the structure of the nanospheres formed during implantation. Some consist in small hollow amorphous nanocapsules with sizes ranging from 30 to 100 nm. Large gas bubbles with diameters up to 300 mn have also been observed in the copper matrix. Electron energy-loss spectroscopy (EELS) measurements performed on the small nanocapsules indicate that their shells are composed of carbon and nitrogen. (c) 2007 Elsevier B.V. All rights reserved. |
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Place of Publication |
Lausanne |
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Wos |
000247715300016 |
Publication Date |
2007-02-25 |
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Series Issue |
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Edition |
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ISSN |
0254-0584; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.084 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.084; 2007 IF: 1.871 |
Call Number |
UA @ lucian @ c:irua:102670 |
Serial |
1258 |
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Author |
Čukarić, N.A.; Tadić, M.Z.; Partoens, B.; Peeters, F.M. |
Title |
The interband optical absorption in silicon quantum wells : application of the 30-band k . p model |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
104 |
Issue |
24 |
Pages |
242103 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The interband optical absorption in Si/SiO2 quantum wells is calculated as function of the well width (W) and the evolution from an indirect to a direct gap material as function of the well width is investigated. In order to compute the electron states in the conduction band, the 30-band k . p model is employed, whereas the 6-band Luttinger-Kohn model is used for the hole states. We found that the effective direct band gap in the quantum well agrees very well with the W-2 scaling result of the single-band model. The interband matrix elements for linear polarized light oscillate with the quantum well width, which agrees qualitatively with a single band calculation. Our theoretical results indicate that the absorption can be maximized by a proper choice of the well width. However, the obtained absorption coefficients are at least an order of magnitude smaller than for a typical direct semiconductor even for a well width of 2 nm. (C) 2014 AIP Publishing LLC. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000337915000033 |
Publication Date |
2014-06-18 |
Series Editor |
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Series Issue |
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Edition |
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ISSN |
0003-6951;1077-3118; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
1 |
Open Access |
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Notes |
; This work was supported by the Ministry of Education, Science, and Technological Development of Serbia, the Flemish fund for Scientific Research (FWO-Vl), and the Methusalem programme of the Flemish government. ; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
Call Number |
UA @ lucian @ c:irua:118448 |
Serial |
1689 |
Permanent link to this record |