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Records |
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Author |
Teodorescu, V.S.; Mihailescu, I.N.; Gyorgy, E.; Luches, A.; Martino, M.; Nistor, L.C.; van Landuyt, J.; Hermann, J. |
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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 |
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. |
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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  |
London |
Editor |
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Language |
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Wos |
A1996VF31900002 |
Publication Date |
2007-07-07 |
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Series Editor |
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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 # |
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Call Number |
UA @ lucian @ c:irua:95238 |
Serial |
3594 |
| Permanent link to this record |
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Author |
Dixon, E.; Hadermann, J.; Hayward, M.A. |
| |
Title |
The synthesis and complex anion-vacancy ordered structure of La0.33Sr0.67MnO2.42 |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| |
Volume |
184 |
Issue |
7 |
Pages |
1791-1799 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The low-temperature topotactic reduction of La0.33Sr0.67MnO3 with NaH results in the formation of La0.33Sr0.67MnO2.42. A combination of neutron powder and electron diffraction data show that La0.33Sr0.67MnO2.42 adopts a novel anion-vacancy ordered structure with a 6-layer OOTOOT' stacking sequence of the octahedral and tetrahedral layers (Pcmb, a=5.5804(1) Å, b=23.4104(7) Å, c=11.2441(3) Å). A significant concentration of anion vacancies at the anion site, which links neighbouring octahedral layers means that only 25% of the octahedral manganese coordination sites actually have 6-fold MnO6 coordination, the remainder being MnO5 square-based pyramidal sites. The chains of cooperatively twisted apex-linked MnO4 tetrahedra adopt an ordered -LRLR- arrangement within each tetrahedral layer. This is the first published example of a fully refined structure of this type which exhibits such intralayer ordering of the twisted tetrahedral chains. The rationale behind the contrasting structures of La0.33Sr0.67MnO2.42 and other previously reported reduced La1−xSrxMnO3−y phases is discussed. |
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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 |
London |
Editor |
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Language |
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Wos |
000292718500032 |
Publication Date |
2011-05-26 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.299 |
Times cited |
8 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.299; 2011 IF: 2.159 |
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Call Number |
UA @ lucian @ c:irua:90885 |
Serial |
3600 |
| Permanent link to this record |
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Author |
Kovba, M.L.; Skolis, Y.Y.; Abakumov, A.M.; Hadermann, J.; Sukhushina, I.S. |
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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. |
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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 |
London |
Editor |
|
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Language |
|
Wos |
000284775000004 |
Publication Date |
2011-02-11 |
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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 |
0036-0244;1531-863X; |
ISBN |
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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 |
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Call Number |
UA @ lucian @ c:irua:99190 |
Serial |
3601 |
| Permanent link to this record |
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Author |
Lajevardipour, A.; Neek-Amal, M.; Peeters, F.M. |
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Title |
Thermomechanical properties of graphene : valence force field model approach |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
24 |
Issue |
17 |
Pages |
175303-175303,8 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Using the valence force field model of Perebeinos and Tersoff (2009 Phys. Rev. B 79 241409(R)), different energy modes of suspended graphene subjected to tensile or compressive strain are studied. By carrying out Monte Carlo simulations it is found that: (i) only for small strains (vertical bar epsilon vertical bar (sic) 0.02) is the total energy symmetrical in the strain, while it behaves completely differently beyond this threshold; (ii) the important energy contributions in stretching experiments are stretching, angle bending, an out-of-plane term, and a term that provides repulsion against pi-pi misalignment; (iii) in compressing experiments the two latter terms increase rapidly, and beyond the buckling transition stretching and bending energies are found to be constant; (iv) from stretching-compressing simulations we calculated the Young's modulus at room temperature 350 +/- 3.15 N m(-1), which is in good agreement with experimental results (340 +/- 50 N m(-1)) and with ab initio results (322-353) N m(-1); (v) molar heat capacity is estimated to be 24.64 J mol(-1) K-1 which is comparable with the Dulong-Petit value, i. e. 24.94 J mol(-1) K-1, and is almost independent of the strain; (vi) nonlinear scaling properties are obtained from height-height correlations at finite temperature; (vii) the used valence force field model results in a temperature independent bending modulus for graphene, and (viii) the Gruneisen parameter is estimated to be 0.64. |
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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 |
London |
Editor |
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Language |
|
Wos |
000303499700012 |
Publication Date |
2012-04-05 |
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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 |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
29 |
Open Access |
|
| |
Notes |
; We acknowledge helpful comments by V Perebeinos, S Costamagna, A Fasolino and J H Los. This work was supported by the Flemish science foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
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Call Number |
UA @ lucian @ c:irua:99123 |
Serial |
3639 |
| Permanent link to this record |
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Author |
Van Aert, S.; Batenburg, K.J.; Rossell, M.D.; Erni, R.; Van Tendeloo, G. |
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Title |
Three-dimensional atomic imaging of crystalline nanoparticles |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| |
Volume |
470 |
Issue |
7334 |
Pages |
374-377 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| |
Abstract |
Determining the three-dimensional (3D) arrangement of atoms in crystalline nanoparticles is important for nanometre-scale device engineering and also for applications involving nanoparticles, such as optoelectronics or catalysis. A nanoparticles physical and chemical properties are controlled by its exact 3D morphology, structure and composition1. Electron tomography enables the recovery of the shape of a nanoparticle from a series of projection images2, 3, 4. Although atomic-resolution electron microscopy has been feasible for nearly four decades, neither electron tomography nor any other experimental technique has yet demonstrated atomic resolution in three dimensions. Here we report the 3D reconstruction of a complex crystalline nanoparticle at atomic resolution. To achieve this, we combined aberration-corrected scanning transmission electron microscopy5, 6, 7, statistical parameter estimation theory8, 9 and discrete tomography10, 11. Unlike conventional electron tomography, only two images of the targeta silver nanoparticle embedded in an aluminium matrixare sufficient for the reconstruction when combined with available knowledge about the particles crystallographic structure. Additional projections confirm the reliability of the result. The results we present help close the gap between the atomic resolution achievable in two-dimensional electron micrographs and the coarser resolution that has hitherto been obtained by conventional electron tomography. |
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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 |
London |
Editor |
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Language |
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Wos |
000287409100037 |
Publication Date |
2011-02-02 |
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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 |
0028-0836;1476-4687; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
40.137 |
Times cited |
341 |
Open Access |
|
| |
Notes |
Esteem 026019 |
Approved |
Most recent IF: 40.137; 2011 IF: 36.280 |
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Call Number |
UA @ lucian @ c:irua:86745 |
Serial |
3644 |
| Permanent link to this record |
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Author |
Schweigert, V.A.; Peeters, F.M. |
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Title |
Time dependent properties of classical artificial atoms |
Type |
A1 Journal article |
| |
Year |
1998 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
10 |
Issue |
|
Pages |
2417-2435 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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 |
London |
Editor |
|
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Language |
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Wos |
000072951000006 |
Publication Date |
2002-08-25 |
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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 |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
18 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.649; 1998 IF: 1.645 |
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Call Number |
UA @ lucian @ c:irua:24175 |
Serial |
3665 |
| Permanent link to this record |
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| |
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Author |
Van Tendeloo, G.; op de Beeck, M.; De Meulenaere, P.; van Dyck, D. |
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Title |
Towards quantitative high resolution electron microscopy? |
Type |
A1 Journal article |
| |
Year |
1995 |
Publication |
Institute of physics conference series |
Abbreviated Journal |
|
| |
Volume |
147 |
Issue |
|
Pages |
67-72 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
The basics of the interpretation of high resolution images showing detail of the order of 0.1 nm are shortly explained here. The use of a field emission source, a CCD camera and an adapted reconstruction method for restoring the projected crystal potential (focus variation method) allows a quantitative interpretation of HREM images. Examples of partially disordered alloys and carbonate ordering in high Tc superconductors are presented. |
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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 |
London |
Editor |
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Language |
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Wos |
A1995BE67F00014 |
Publication Date |
0000-00-00 |
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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 |
0-7503-0357-3; 0951-3248; 0305-2346 |
ISBN |
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Additional Links |
UA library record; WoS full record; |
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Impact Factor |
|
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
no |
| |
Call Number |
UA @ lucian @ c:irua:13015 |
Serial |
3688 |
| Permanent link to this record |
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Author |
Wang, H.; Cuppens, J.; Biermans, E.; Bals, S.; Fernandez-Ballester, L.; Kvashnina, K.O.; Bras, W.; van Bael, M.J.; Temst, K.; Vantomme, A. |
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Title |
Tuning of the size and the lattice parameter of ion-beam synthesized Pb nanoparticles embedded in Si |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
| |
Volume |
45 |
Issue |
3 |
Pages |
035301-035301,7 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The size and lattice constant evolution of Pb nanoparticles (NPs) synthesized by high fluence implantation in crystalline Si have been studied with a variety of experimental techniques. Results obtained from small-angle x-ray scattering showed that the Pb NPs grow with increasing implantation fluence and annealing duration. The theory of NP growth kinetics can be applied to qualitatively explain the size evolution of the Pb NPs during the implantation and annealing processes. Moreover, the lattice constant of the Pb NPs was evaluated by conventional x-ray diffraction. The lattice dilatation was observed to decrease with increasing size of the Pb NPs. Such lattice constant tuning can be attributed to the pseudomorphism caused by the lattice mismatch between the Pb NPs and the Si matrix. |
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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 |
London |
Editor |
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Language |
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Wos |
000299308400008 |
Publication Date |
2011-12-23 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
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Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.588 |
Times cited |
5 |
Open Access |
|
| |
Notes |
Fwo; Iap |
Approved |
Most recent IF: 2.588; 2012 IF: 2.528 |
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Call Number |
UA @ lucian @ c:irua:94208 |
Serial |
3754 |
| Permanent link to this record |
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Author |
Rosova, A.; Krekels, T.; Van Tendeloo, G.; Darriet, B.; Chambon, M. |
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Title |
Twin boundary structure of Au-doped YBa2Cu3O7-x single crystals |
Type |
A1 Journal article |
| |
Year |
1993 |
Publication |
Ferroelectrics |
Abbreviated Journal |
Ferroelectrics |
| |
Volume |
141 |
Issue |
|
Pages |
87-94 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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 |
London |
Editor |
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| |
Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0015-0193 |
ISBN |
|
Additional Links |
UA library record |
| |
Impact Factor |
0.469 |
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
no |
| |
Call Number |
UA @ lucian @ c:irua:7502 |
Serial |
3766 |
| Permanent link to this record |
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Author |
Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
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Title |
A two-component mixture of charged particles confined in a channel: melting |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
22 |
Issue |
28 |
Pages |
11 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The melting of a binary system of charged particles confined in a quasi-one-dimensional parabolic channel is studied through Monte Carlo simulations. At zero temperature the particles are ordered in parallel chains. The melting is anisotropic and different melting temperatures are obtained according to the spatial direction, and the different kinds of particles present in the system. Melting is very different for the single-, two- and four-chain configurations. A temperature induced structural phase transition is found between two different four-chain ordered states which is absent in the mono-disperse system. In the mixed regime, where the two kinds of particles are only slightly different, melting is almost isotropic and a thermally induced homogeneous distribution of the distinct kinds of charges is observed. |
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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 |
London |
Editor |
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Language |
|
Wos |
000279257300023 |
Publication Date |
2010-06-16 |
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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 |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
10 |
Open Access |
|
| |
Notes |
; This work was supported by CNPq, the Flemish Science Foundation (FWO-V1) and the bilateral program between Flanders and Brazil. ; |
Approved |
Most recent IF: 2.649; 2010 IF: 2.332 |
| |
Call Number |
UA @ lucian @ c:irua:83862 |
Serial |
3771 |
| Permanent link to this record |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M. |
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Title |
Ultra-small metallic grains : effect of statistical fluctuations of the chemical potential on superconducting correlations and vice versa |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
24 |
Issue |
27 |
Pages |
275701 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Superconducting correlations in an isolated metallic grain are governed by the interplay between two energy scales: the mean level spacing delta and the bulk pairing gap Delta(0), which are strongly influenced by the position of the chemical potential with respect to the closest single-electron level. In turn superconducting correlations affect the position of the chemical potential. Within the parity projected BCS model we investigate the probability distribution of the chemical potential in a superconducting grain with randomly distributed single-electron levels. Taking into account statistical fluctuations of the chemical potential due to the pairing interaction, we find that such fluctuations have a significant impact on the critical level spacing delta(c) at which the superconducting correlations cease: the critical ratio delta(c)/Delta(0) at which superconductivity disappears is found to be increased. |
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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 |
London |
Editor |
|
| |
Language |
|
Wos |
000305653100012 |
Publication Date |
2012-06-21 |
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Series Editor |
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Series Title |
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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 |
9 |
Open Access |
|
| |
Notes |
; This work was supported by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF network INSTANS. MDC and AAS are grateful to A Vagov for stimulating discussions. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
| |
Call Number |
UA @ lucian @ c:irua:100280 |
Serial |
3793 |
| Permanent link to this record |
| |
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| |
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Author |
Pereira, J.M.; Peeters, F.M.; Costa Filho, R.N.; Farias, G.A. |
| |
Title |
Valley polarization due to trigonal warping on tunneling electrons in graphene |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
21 |
Issue |
4 |
Pages |
045301,1-045301,4 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The effect of trigonal warping on the transmission of electrons tunneling through potential barriers in graphene is investigated. We present calculations of the transmission coefficient for single and double barriers as a function of energy, incidence angle and barrier heights. The results show remarkable valley-dependent directional effects for barriers oriented parallel to the armchair or parallel to the zigzag direction. These results indicate that electrostatic gates can be used as valley filters in graphene-based devices. |
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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 |
London |
Editor |
|
| |
Language |
|
Wos |
000262354700004 |
Publication Date |
2008-12-20 |
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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 |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
78 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
| |
Call Number |
UA @ lucian @ c:irua:75736 |
Serial |
3834 |
| Permanent link to this record |
| |
|
| |
|
Author |
Xu, W.; Peeters, F.M.; Devreese, J.T. |
| |
Title |
Warm-electron transport in a two-dimensional semiconductor |
Type |
A1 Journal article |
| |
Year |
1992 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
| |
Volume |
7 |
Issue |
|
Pages |
1251-1256 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
| |
Abstract |
|
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
A1992JT73000006 |
Publication Date |
0000-00-00 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.19 |
Times cited |
3 |
Open Access |
|
| |
Notes |
|
Approved |
no |
| |
Call Number |
UA @ lucian @ c:irua:2915 |
Serial |
3903 |
| Permanent link to this record |
| |
|
| |
|
Author |
Rakhimov, K.Y.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
| |
Title |
Wavepacket scattering of Dirac and Schrödinger particles on potential and magnetic barriers |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
23 |
Issue |
27 |
Pages |
275801,1-275801,16 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
We investigate the dynamics of a charged particle moving in a graphene layer and in a two-dimensional electron gas, where it obeys the Dirac and the Schrödinger equations, respectively. The charge carriers are described as Gaussian wavepackets. The dynamics of the wavepackets is studied numerically by solving both quantum-mechanical and relativistic equations of motion. The scattering of such wavepackets by step-like magnetic and potential barriers is analysed for different values of wavepacket energy and width. We find: (1) that the average position of the wavepacket does not coincide with the classical trajectory, and (2) that, for slanted incidence, the path of the centre of mass of the wavepacket does not have to penetrate the barrier during the scattering process. Trembling motion of the charged particle in graphene is observed in the absence of an external magnetic field and can be enhanced by a substrate-induced mass term. |
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Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000291993600009 |
Publication Date |
2011-06-18 |
| |
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 |
32 |
Open Access |
|
| |
Notes |
; Discussions with A Matulis are gratefully acknowledged. KR is beneficiary of a mobility grant from the Belgian Federal Science Policy Office, co-funded by the European Commission and was supported in part by a grant of the Third World Academy of Sciences (ref. 09-188 RG/PHYS/AS-I). In addition, this work was financially supported by CNPq, under contract NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES, the Bilateral programme between Flanders and Brazil, the joint project CNPq-FWO, the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 2.649; 2011 IF: 2.546 |
| |
Call Number |
UA @ lucian @ c:irua:90880 |
Serial |
3908 |
| Permanent link to this record |
| |
|
| |
|
Author |
Sivek, J.; Sahin, H.; Partoens, B.; Peeters, F.M. |
| |
Title |
Giant magnetic anisotropy in doped single layer molybdenum disulfide and fluorographene |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
28 |
Issue |
28 |
Pages |
195301 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Stable monolayer materials based on existing, well known and stable two-dimensional crystal fluorographene and molybdenum disulfide are predicted to exhibit a huge magnetocrystalline anisotropy when functionalized with adsorbed transition metal atoms at vacant sides. Ab initio calculations within the density-functional theory formalism were performed to investigate the adsorption of the transitional metals in a single S (or F) vacancy of monolayer molybdenum disulfide (or fluorographene). We found strong bonding of the transitional metal atoms to the vacant sites with binding energies ranging from 2.5 to 5.2 eV. Our calculations revealed that these systems with adsorbed metal atoms exhibit a magnetic anisotropy, specifically the structures including Os and Ir show a giant magnetocrystalline anisotropy energy of 31-101 meV. Our results demonstrate the possibility of obtaining stable monolayer materials with huge magnetocrystalline anisotropy based on preexisting, well known and stable two-dimensional crystals: fluorographene and molybdenum disulfide. We believe that the results obtained here are useful not only for deeper understanding of the origin of magnetocrystalline anisotropy but also for the design of monolayer optoelectronic devices with novel functionalities. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000374394700007 |
Publication Date |
2016-04-13 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0953-8984 |
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 |
| |
Call Number |
UA @ lucian @ c:irua:133611 |
Serial |
4185 |
| Permanent link to this record |
| |
|
| |
|
Author |
Zarenia, M.; Perali, A.; Peeters, F.M.; Neilson, D. |
| |
Title |
Large gap electron-hole superfluidity and shape resonances in coupled graphene nanoribbons |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
| |
Volume |
6 |
Issue |
6 |
Pages |
24860 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
We predict enhanced electron-hole superfluidity in two coupled electron-hole armchair-edge terminated graphene nanoribbons separated by a thin insulating barrier. In contrast to graphene monolayers, the multiple subbands of the nanoribbons are parabolic at low energy with a gap between the conduction and valence bands, and with lifted valley degeneracy. These properties make screening of the electron-hole interaction much weaker than for coupled electron-hole monolayers, thus boosting the pairing strength and enhancing the superfluid properties. The pairing strength is further boosted by the quasi one-dimensional quantum confinement of the carriers, as well as by the large density of states near the bottom of each subband. The latter magnifies superfluid shape resonances caused by the quantum confinement. Several superfluid partial condensates are present for finite-width nanoribbons with multiple subbands. We find that superfluidity is predominately in the strongly-coupled BEC and BCS-BEC crossover regimes, with large superfluid gaps up to 100 meV and beyond. When the gaps exceed the subband spacing, there is significant mixing of the subbands, a rounding of the shape resonances, and a resulting reduction in the one-dimensional nature of the system. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000374654500002 |
Publication Date |
2016-04-25 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.259 |
Times cited |
7 |
Open Access |
|
| |
Notes |
; M.Z. acknowledges support by the Flemish Science Foundation (FWO-Vl), the University Research Fund (BOF), and the European Science Foundation (POLATOM). A.P. and D.N. acknowledge support by the University of Camerino FAR project CESEMN. The authors thank the colleagues involved in the MultiSuper International Network (http://www.multisuper.org) for exchange of ideas and suggestions for this work. ; |
Approved |
Most recent IF: 4.259 |
| |
Call Number |
UA @ lucian @ c:irua:133619 |
Serial |
4201 |
| Permanent link to this record |
| |
|
| |
|
Author |
Croitoru, M.D.; Shanenko, A.A.; Vagov, A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
| |
Title |
Phonon limited superconducting correlations in metallic nanograins |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
| |
Volume |
5 |
Issue |
5 |
Pages |
16515 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
Conventional superconductivity is inevitably suppressed in ultra-small metallic grains for characteristic sizes smaller than the Anderson limit. Experiments have shown that above the Anderson limit the critical temperature may be either enhanced or reduced when decreasing the particle size, depending on the superconducting material. In addition, there is experimental evidence that whether an enhancement or a reduction is found depends on the strength of the electronphonon interaction in the bulk. We reveal how the strength of the e-ph interaction interplays with the quantum-size effect and theoretically obtain the critical temperature of the superconducting nanograins in excellent agreement with experimental data. We demonstrate that strong e-ph scattering smears the peak structure in the electronic density-of-states of a metallic grain and enhances the electron mass, and thereby limits the highest T-c achievable by quantum confinement. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000364647700001 |
Publication Date |
2015-11-13 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.259 |
Times cited |
9 |
Open Access |
|
| |
Notes |
; This work was supported by the Belgian Science Policy (BELSPO Back to Belgium Grant), the Research Foundation Flanders (FWO), the Methusalem Foundation of the Flemish Government, TOPBOF-UA, and the bilateral project CNPq-FWO. M.D.C. acknowledges fruitful discussions with V. Z. Kresin, S. N. Klimin and V. N. Gladilin. ; |
Approved |
Most recent IF: 4.259; 2015 IF: 5.578 |
| |
Call Number |
UA @ lucian @ c:irua:129543 |
Serial |
4224 |
| Permanent link to this record |
| |
|
| |
|
Author |
Ryabova, A.S.; Napolskiy, F.S.; Poux, T.; Istomin, S.Y.; Bonnefont, A.; Antipin, D.M.; Baranchikov, A.Y.; Levin, E.E.; Abakumov, A.M.; Kéranguéven, G.; Antipov, E.V.; Tsirlina, G.A.; Savinova, E.R.; |
| |
Title |
Rationalizing the influence of the Mn(IV)/Mn(III) red-Ox transition on the electrocatalytic activity of manganese oxides in the oxygen reduction reaction |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Electrochimica acta |
Abbreviated Journal |
Electrochim Acta |
| |
Volume |
187 |
Issue |
187 |
Pages |
161-172 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
Knowledge on the mechanisms of oxygen reduction reaction (ORR) and descriptors linking the catalytic activity to the structural and electronic properties of transition metal oxides enable rational design of more efficient catalysts. In this work ORR electrocatalysis was studied on a set of single and complex Mn (III) oxides with a rotating disc electrode method and cyclic voltammetry. We discovered an exponential increase of the specific electrocatalytic activity with the potential of the surface Mn(IV)/Mn(III) red-ox couple, suggesting the latter as a new descriptor for the ORR electrocatalysis. The observed dependence is rationalized using a simple mean-field kinetic model considering availability of the Mn( III) centers and adsorbate-adsorbate interactions. We demonstrate an unprecedented activity of Mn2O3, ca. 40 times exceeding that of MnOOH and correlate the catalytic activity of Mn oxides to their crystal structure. (C) 2015 Elsevier Ltd. All rights reserved. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000367235600019 |
Publication Date |
2015-11-10 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0013-4686 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.798 |
Times cited |
51 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.798 |
| |
Call Number |
UA @ lucian @ c:irua:131096 |
Serial |
4237 |
| Permanent link to this record |
| |
|
| |
|
Author |
Curran, P.J.; Desoky, W.M.; Milošević, M.V.; Chaves, A.; Laloe, J.-B.; Moodera, J.S.; Bending, S.J. |
| |
Title |
Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
| |
Volume |
5 |
Issue |
5 |
Pages |
15569 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
Scanning Hall probe microscopy (SHPM) has been used to study vortex structures in thin epitaxial films of the superconductor MgB2. Unusual vortex patterns observed in MgB2 single crystals have previously been attributed to a competition between short-range repulsive and long-range attractive vortex-vortex interactions in this two band superconductor; the type 1.5 superconductivity scenario. Our films have much higher levels of disorder than bulk single crystals and therefore both superconducting condensates are expected to be pushed deep into the type 2 regime with purely repulsive vortex interactions. We observe broken symmetry vortex patterns at low fields in all samples after field-cooling from above T-c. These are consistent with those seen in systems with competing repulsions on disparate length scales, and remarkably similar structures are reproduced in dirty two band Ginzburg-Landau calculations, where the simulation parameters have been defined by experimental observations. This suggests that in our dirty MgB2 films, the symmetry of the vortex structures is broken by the presence of vortex repulsions with two different lengthscales, originating from the two distinct superconducting condensates. This represents an entirely new mechanism for spontaneous symmetry breaking in systems of superconducting vortices, with important implications for pinning phenomena and high current density applications. |
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Address |
|
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Corporate Author |
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Thesis |
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000363306000002 |
Publication Date |
2015-10-23 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.259 |
Times cited |
12 |
Open Access |
|
| |
Notes |
; P.J.C. and S.J.B. acknowledge support from EPSRC in the UK under grant number EP/J010626/1 and the NanoSC COST Action MP-1201. M.V.M. thanks the Research Foundation-Flanders (FWO) and CAPES Brazil. A.C. acknowledges the financial support of CNPq, under the PRONEX/FUNCAP and PQ programs. J.-B.L. and J.S.M. acknowledge ONR Grant N00014-06-01-0235. ; |
Approved |
Most recent IF: 4.259; 2015 IF: 5.578 |
| |
Call Number |
UA @ lucian @ c:irua:129450 |
Serial |
4248 |
| Permanent link to this record |
| |
|
| |
|
Author |
Charkin, D.O.; Akinfiev, V.S.; Alekseeva, A.M.; Batuk, M.; Abakumov, A.M.; Kazakov, S.M. |
| |
Title |
Synthesis and cation distribution in the new bismuth oxyhalides with the Sillen-Aurivillius intergrowth structures |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
| |
Volume |
44 |
Issue |
44 |
Pages |
20568-20576 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
About 20 new compounds with the Sillen-Aurivillius intergrowth structure, (MeMeBi3Nb2O11X)-Me-1-Bi-2 (Me-1 = Pb, Sr, Ba; Me-2 = Ca, Sr, Ba; X = Cl, Br, I), have been prepared. They are composed of stacking of [ANb(2)O(7)] perovskite blocks, fluorite-type [M2O2] blocks and halogen sheets. The cation distribution between the fluorite and perovskite layers has been studied for Ba2Bi3Nb2O11I, Ca1.25Sr0.75Bi3Nb2O11Cl, BaCaBi3Nb2O11Br and Sr2Bi3Nb2O11Cl. The smaller Me cations tend to reside in the perovskite block while the larger ones are situated in the fluorite-type block. The distribution of the elements was confirmed for BaCaBi3Nb2O11Br using energy dispersive X-ray analysis combined with scanning transmission electron microscopy (STEM-EDX). An electron diffraction study of this compound reveals a local symmetry lowering caused by weakly correlated rotation of NbO6 octahedra. Based on our findings, we suggest a new stability criterion for mixed-layer structures, which is that net charges of any two consecutive layers do not compensate for each other and only the whole layer sequence is electroneutral. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000365411500036 |
Publication Date |
2015-10-30 |
| |
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 |
5 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:130330 |
Serial |
4256 |
| Permanent link to this record |
| |
|
| |
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Author |
Rozova, M.G.; Grigoriev, V.V.; Bobrikov, I.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Antipov, E.V.; Tsirlin, A.A.; Abakumov, A.M. |
| |
Title |
Synthesis, structure and magnetic ordering of the mullite-type Bi2Fe4-xCrxO9 solid solutions with a frustrated pentagonal Cairo lattice |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
| |
Volume |
45 |
Issue |
45 |
Pages |
1192-1200 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
Highly homogeneous mullite-type solid solutions Bi2Fe4-xCrxO9 (x = 0.5, 1, 1.2) were synthesized using a soft chemistry technique followed by a solid-state reaction in Ar. The crystal structure of Bi2Fe3CrO9 was investigated using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy (S.G. Pbam, a = 7.95579(9) angstrom , b = 8.39145(9) angstrom, c = 5.98242(7) angstrom, R-F(X-ray) = 0.022, R-F(neutron) = 0.057). The ab planes in the structure are tessellated with distorted pentagonal loops built up by three tetrahedrally coordinated Fe sites and two octahedrally coordinated Fe/Cr sites, linked together in the ab plane by corner-sharing forming a pentagonal Cairo lattice. Magnetic susceptibility measurements and powder neutron diffraction show that the compounds order antiferromagnetically (AFM) with the Neel temperatures decreasing upon increasing the Cr content from T-N similar to 250 K for x = 0 to T-N similar to 155 K for x = 1.2. The magnetic structure of Bi2Fe3CrO9 at T = 30 K is characterized by a propagation vector k = (1/2,1/2,1/2). The tetrahedrally coordinated Fe cations form singlet pairs within dimers of corner-sharing tetrahedra, but spins on the neighboring dimers are nearly orthogonal. The octahedrally coordinated (Fe, Cr) cations form antiferromagnetic up-up-down-down chains along c, while the spin arrangement in the ab plane is nearly orthogonal between nearest neighbors and collinear between second neighbors. The resulting magnetic structure is remarkably different from the one in pure Bi2Fe4O9 and features several types of spin correlations even on crystallographically equivalent exchange that may be caused by the simultaneous presence of Fe and Cr on the octahedral site. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000367614700041 |
Publication Date |
2015-11-30 |
| |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| |
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 |
|
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:131095 |
Serial |
4257 |
| Permanent link to this record |
| |
|
| |
|
Author |
Cukaric, N.A.; Partoens, B.; Tadic, M.Z.; Arsoski, V.V.; Peeters, F.M. |
| |
Title |
The 30-band k . p theory of valley splitting in silicon thin layers |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
28 |
Issue |
28 |
Pages |
195303 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The valley splitting of the conduction-band states in a thin silicon-on-insulator layer is investigated using the 30-band k . p theory. The system composed of a few nm thick Si layer embedded within thick SiO2 layers is analyzed. The valley split states are found to cross periodically with increasing quantum well width, and therefore the energy splitting is an oscillatory function of the quantum well width, with period determined by the wave vector K-0 of the conduction band minimum. Because the valley split states are classified by parity, the optical transition between the ground hole state and one of those valley split conduction band states is forbidden. The oscillations in the valley splitting energy decrease with electric field and with smoothing of the composition profile between the well and the barrier by diffusion of oxygen from the SiO2 layers to the Si quantum well. Such a smoothing also leads to a decrease of the interband transition matrix elements. The obtained results are well parametrized by the effective two-valley model, but are found to disagree from previous 30-band calculations. This discrepancy could be traced back to the fact that the basis for the numerical solution of the eigenproblem must be restricted to the first Brillouin zone in order to obtain quantitatively correct results for the valley splitting. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
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| |
Language |
|
Wos |
000374394700009 |
Publication Date |
2016-04-19 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| |
Impact Factor |
2.649 |
Times cited |
|
Open Access |
|
| |
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: 2.649 |
| |
Call Number |
UA @ lucian @ c:irua:133610 |
Serial |
4261 |
| Permanent link to this record |
| |
|
| |
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Author |
Suslu, A.; Wu, K.; Sahin, H.; Chen, B.; Yang, S.; Cai, H.; Aoki, T.; Horzum, S.; Kang, J.; Peeters, F.M.; Tongay, S.; |
| |
Title |
Unusual dimensionality effects and surface charge density in 2D Mg(OH)2 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
| |
Volume |
6 |
Issue |
6 |
Pages |
20525 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
We present two-dimensional Mg(OH)(2) sheets and their vertical heterojunctions with CVD-MoS2 for the first time as flexible 2D insulators with anomalous lattice vibration and chemical and physical properties. New hydrothermal crystal growth technique enabled isolation of environmentally stable monolayer Mg(OH)(2) sheets. Raman spectroscopy and vibrational calculations reveal that the lattice vibrations of Mg(OH)(2) have fundamentally different signature peaks and dimensionality effects compared to other 2D material systems known to date. Sub-wavelength electron energy-loss spectroscopy measurements and theoretical calculations show that Mg(OH)(2) is a 6 eV direct-gap insulator in 2D, and its optical band gap displays strong band renormalization effects from monolayer to bulk, marking the first experimental confirmation of confinement effects in 2D insulators. Interestingly, 2D-Mg(OH)(2) sheets possess rather strong surface polarization (charge) effects which is in contrast to electrically neutral h-BN materials. Using 2D-Mg(OH)(2) sheets together with CVD-MoS2 in the vertical stacking shows that a strong change transfer occurs from n-doped CVD-MoS2 sheets to Mg(OH)(2), naturally depleting the semiconductor, pushing towards intrinsic doping limit and enhancing overall optical performance of 2D semiconductors. Results not only establish unusual confinement effects in 2D-Mg(OH)(2), but also offer novel 2D-insulating material with unique physical, vibrational, and chemical properties for potential applications in flexible optoelectronics. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
| |
Language |
|
Wos |
000369510300001 |
Publication Date |
2016-02-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
4.259 |
Times cited |
39 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS is supported by a FWO Pegasus Long Marie Curie Fellowship. JK is supported by a FWO Pegasus-short Marie Curie Fellowship. We acknowledge the use of John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. ; |
Approved |
Most recent IF: 4.259 |
| |
Call Number |
UA @ lucian @ c:irua:131615 |
Serial |
4272 |
| Permanent link to this record |
| |
|
| |
|
Author |
Tang, Y.; Hunter, E.C.; Battle, P.D.; Sena, R.P.; Hadermann, J.; Avdeev, M.; Cadogan, J.M. |
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Title |
Structural chemistry and magnetic properties of the perovskite Sr3Fe2TeO9 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| |
Volume |
242 |
Issue |
242 |
Pages |
86-95 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
A polycrystalline sample of perovskite-like Sr3Fe2TeO9 has been prepared in a solid-state reaction and studied by a combination of electron microscopy, Mossbauer spectroscopy, magnetometry, X-ray diffraction and neutron diffraction. The majority of the reaction product is shown to be a trigonal phase with a 2:1 ordered arrangement of Fe3+ and Te6+ cations. However, the sample is prone to nano twinning and tetragonal domains with a different pattern of cation ordering exist within many crystallites. Antiferromagnetic ordering exists in the trigonal phase at 300 K and Sr3Fe2TeO9 is thus the first example of a perovskite with 2:1 trigonal cation ordering to show long-range magnetic order. At 300 K the antiferromagnetic phase coexists with two paramagnetic phases which show spin -glass behaviour below similar to 80 K. (C) 2016 The Authors. Published by Elsevier Inc. |
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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 |
London |
Editor |
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Language |
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Wos |
000382429600012 |
Publication Date |
2016-06-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.299 |
Times cited |
12 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.299 |
| |
Call Number |
UA @ lucian @ c:irua:135682 |
Serial |
4310 |
| Permanent link to this record |
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|
| |
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Author |
Sena, R.P.; Hadermann, J.; Chin, C.-M.; Hunter, E.C.; Battle, P.D. |
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Title |
Structural chemistry and magnetic properties of the perovskite SrLa2Ni2TeO9 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| |
Volume |
243 |
Issue |
243 |
Pages |
304-311 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
A polycrystalline sample of SrLa2Ni2TeO9 has been synthesized using a standard ceramic method and characterized by neutron diffraction, magnetometry and electron microscopy. The compound adopts a monoclinic, perovskite-like structure with space group P2(1)/n in and unit cell parameters a=5.6008(1), b = 5.5872(1), c=7.9018(2) angstrom, p=90.021(6)degrees at room temperature. The two crystallographically-distinct B sites are occupied by Ni2+ and Te6+ in ratios of 83:17 and 50:50. Both ac and dc magnetometry suggest that the compound is a spin glass below 35 K but the neutron diffraction data show that some regions of the sample are antiferromagnetic. Electron microscopy revealed twinning on a nanoscale and local variations in composition. These defects are thought to be responsible for the presence of two distinct types of antiferromagnetic ordering. (C) 2016 The Authors. Published by Elsevier Inc. |
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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 |
London |
Editor |
|
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Language |
|
Wos |
000384874100041 |
Publication Date |
2016-09-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.299 |
Times cited |
6 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.299 |
| |
Call Number |
UA @ lucian @ c:irua:137232 |
Serial |
4403 |
| Permanent link to this record |
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| |
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Author |
Milovanovic, S.P.; Peeters, F.M. |
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Title |
Strained graphene Hall bar |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
29 |
Issue |
29 |
Pages |
075601 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, RB, around zero-magnetic field and the occurrence of side-peaks in RB. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in RB are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads. |
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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 |
London |
Editor |
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Language |
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Wos |
000391584900001 |
Publication Date |
2016-12-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
12 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. ; |
Approved |
Most recent IF: 2.649 |
| |
Call Number |
UA @ lucian @ c:irua:140381 |
Serial |
4464 |
| Permanent link to this record |
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Author |
Bogaerts, A.; Khosravian, N.; Van der Paal, J.; Verlackt, C.C.W.; Yusupov, M.; Kamaraj, B.; Neyts, E.C. |
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Title |
Multi-level molecular modelling for plasma medicine |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal Of Physics D-Applied Physics |
Abbreviated Journal |
J Phys D Appl Phys |
| |
Volume |
49 |
Issue |
5 |
Pages |
054002-54019 |
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Keywords |
A1 Journal article; Plasma, laser ablation and surface modeling – Antwerp (PLASMANT) |
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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 |
London |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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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 |
0022-3727 |
ISBN |
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Additional Links |
UA library record |
| |
Impact Factor |
2.588 |
Times cited |
|
Open Access |
|
| |
Notes |
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Approved |
Most recent IF: 2.588 |
| |
Call Number |
UA @ lucian @ c:irua:129798 |
Serial |
4467 |
| Permanent link to this record |
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Author |
Peelaers, H.; Durgun, E.; Partoens, B.; Bilc, D.I.; Ghosez, P.; Van de Walle, C.G.; Peeters, F.M. |
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Title |
Ab initio study of hydrogenic effective mass impurities in Si nanowires |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| |
Volume |
29 |
Issue |
29 |
Pages |
095303 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The effect of B and P dopants on the band structure of Si nanowires is studied using electronic structure calculations based on density functional theory. At low concentrations a dispersionless band is formed, clearly distinguishable from the valence and conduction bands. Although this band is evidently induced by the dopant impurity, it turns out to have purely Si character. These results can be rigorously analyzed in the framework of effective mass theory. In the process we resolve some common misconceptions about the physics of hydrogenic shallow impurities, which can be more clearly elucidated in the case of nanowires than would be possible for bulk Si. We also show the importance of correctly describing the effect of dielectric confinement, which is not included in traditional electronic structure calculations, by comparing the obtained results with those of G(0)W(0) calculations. |
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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 |
London |
Editor |
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Language |
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Wos |
000395103900002 |
Publication Date |
2017-01-06 |
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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 |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
2.649 |
Times cited |
1 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the NSF MRSEC Program under award No. DMR11-21053, and the Army Research Office (W911NF-13-1-0380). DIB acknowledges financial support from the grant of the Romanian National Authority for Scientific Research, CNCS UEFISCDI, project No. PN-II-RU-TE-2011-3-0085. Ph G acknowledges a research professorship of the Francqui foundation and financial support of the ARC project AIMED and FNRS project HiT4FiT. This research used resources of the Ceci HPC Center funded by F R S-FNRS (Grant No. 2.5020.1) and of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231. ; |
Approved |
Most recent IF: 2.649 |
| |
Call Number |
UA @ lucian @ c:irua:142447 |
Serial |
4584 |
| Permanent link to this record |
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Author |
Mikhailova, D.; Kuratieva, N.N.; Utsumi, Y.; Tsirlin, A.A.; Abakumov, A.M.; Schmidt, M.; Oswald, S.; Fuess, H.; Ehrenberg, H. |
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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 |
1606-1617 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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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 |
London |
Editor |
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Language |
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Wos |
000395442700030 |
Publication Date |
2016-12-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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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 |
| Permanent link to this record |
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| |
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Author |
Zebrowski, D.P.; Peeters, F.M.; Szafran, B. |
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Title |
Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
| |
Volume |
32 |
Issue |
6 |
Pages |
065016 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed. |
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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 |
London |
Editor |
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Language |
|
Wos |
000402405800007 |
Publication Date |
2017-04-19 |
| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| |
Impact Factor |
2.305 |
Times cited |
|
Open Access |
|
| |
Notes |
; This work was supported by the National Science Centre according to decision DEC-2013/11/B/ST3/03837 and by the Flemish Science Foundation (FWO-VL). ; |
Approved |
Most recent IF: 2.305 |
| |
Call Number |
UA @ lucian @ c:irua:144238 |
Serial |
4646 |
| Permanent link to this record |
