| |
Records |
|
Author |
Tsirlin, A.A.; Abakumov, A.M.; Van Tendeloo, G.; Rosner, H. |
| |
Title |
Interplay of atomic displacement in the quantum magnet (CuCI)LaNb2O7 |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
5 |
Pages |
054107,1-054107,12 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
We report on the crystal structure of the quantum magnet CuClLaNb2O7 that was controversially described with respect to its structural organization and magnetic behavior. Using high-resolution synchrotron powder x-ray diffraction, electron diffraction, transmission electron microscopy, and band-structure calculations, we solve the room-temperature structure of this compound -CuClLaNb2O7 and find two high-temperature polymorphs. The -CuClLaNb2O7 phase, stable above 640 K, is tetragonal with asub=3.889 Å, csub =11.738 Å, and the space group P4/mmm. In the -CuClLaNb2O7 structure, the Cu and Cl atoms are randomly displaced from the special positions along the 100 directions. The phase asub2asubcsub, space group Pbmm and the phase 2asub2asubcsub, space group Pbam are stable between 640 K and 500 K and below 500 K, respectively. The structural changes at 500 and 640 K are identified as order-disorder phase transitions. The displacement of the Cl atoms is frozen upon the → transformation while a cooperative tilting of the NbO6 octahedra in the phase further eliminates the disorder of the Cu atoms. The low-temperature -CuClLaNb2O7 structure thus combines the two types of the atomic displacements that interfere due to the bonding between the Cu atoms and the apical oxygens of the NbO6 octahedra. The precise structural information resolves the controversy between the previous computation-based models and provides the long-sought input for understanding CuClLaNb2O7 and related compounds with unusual magnetic properties. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication  |
|
Editor |
|
| |
Language |
|
Wos |
000280849400001 |
Publication Date |
2010-08-12 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:83991 |
Serial |
1706 |
| Permanent link to this record |
| |
|
| |
|
Author |
Li, L.L.; Xu, W.; Peeters, F.M. |
| |
Title |
Intrinsic optical anisotropy of [001]-grown short-period InAs/GaSb superlattices |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
23 |
Pages |
235422-235422,10 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
We theoretically investigate the intrinsic optical anisotropy or polarization induced by the microscopic interface asymmetry (MIA) in no-common-atom (NCA) InAs/GaSb superlattices (SLs) grown along the [001] direction. The eight-band K⋅P model is used to calculate the electronic band structures and incorporates the MIA effect. A Boltzmann equation approach is employed to calculate the optical properties. We found that in NCA InAs/GaSb SLs, the MIA effect causes a large in-plane optical anisotropy for linearly polarized light and the largest anisotropy occurs for light polarized along the [110] and [11̅ 0] directions. The relative difference between the optical-absorption coefficient for [110]-polarized light and that for [11̅ 0]-polarized light is found to be larger than 50%. The dependence of the in-plane optical anisotropy on temperature, photoexcited carrier density, and layer width is examined in detail. This study is important for optical devices which require the polarization control and selectivity. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000286768800007 |
Publication Date |
2010-12-13 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
18 |
Open Access |
|
| |
Notes |
; This work was supported partly by the Flemish Science Foundation (FWO-VL), the Belgium Science Policy (IAP), the NSF of China (Grants No. 10664006, No. 10504036, and No. 90503005), Special Funds of 973 Project of China (Grant No. 2005CB623603), and Knowledge Innovation Program of the Chinese Academy of Sciences. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:88909 |
Serial |
1717 |
| Permanent link to this record |
| |
|
| |
|
Author |
Brammertz, G.; Oueslati, S.; Buffiere, M.; Bekaert, J.; El Anzeery, H.; Messaoud, K.B.; Sahayaraj, S.; Nuytten, T.; Koble, C.; Meuris, M.; Poortmans, J.; |
| |
Title |
Investigation of properties limiting efficiency in Cu2ZnSnSe4-based solar cells |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
IEEE journal of photovoltaics |
Abbreviated Journal |
Ieee J Photovolt |
| |
Volume |
5 |
Issue |
5 |
Pages |
649-655 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
We have investigated different nonidealities in Cu2ZnSnSe4CdSZnO solar cells with 9.7% conversion efficiency, in order to determine what is limiting the efficiency of these devices. Several nonidealities could be observed. A barrier of about 300 meV is present for electron flow at the absorberbuffer heterojunction leading to a strong crossover behavior between dark and illuminated currentvoltage curves. In addition, a barrier of about 130 meV is present at the Moabsorber contact, which could be reduced to 15 meV by inclusion of a TiN interlayer. Admittance spectroscopy results on the devices with the TiN backside contact show a defect level with an activation energy of 170 meV. Using all parameters extracted by the different characterization methods for simulations of the two-diode model including injection and recombination currents, we come to the conclusion that our devices are limited by the large recombination current in the depletion region. Potential fluctuations are present in the devices as well, but they do not seem to have a special degrading effect on the devices, besides a probable reduction in minority carrier lifetime through enhanced recombination through the band tail defects. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000353524800026 |
Publication Date |
2014-12-19 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2156-3381;2156-3403; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.712 |
Times cited |
13 |
Open Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.712; 2015 IF: 3.165 |
| |
Call Number |
c:irua:123717 |
Serial |
1734 |
| Permanent link to this record |
| |
|
| |
|
Author |
Buffière, M.; Brammertz, G.; Sahayaraj, S.; Batuk, M.; Khelifi, S.; Mangin, D.; El Mel, A.A.; Arzel, L.; Hadermann, J.; Meuris, M.; Poortmans, J.; |
| |
Title |
KCN chemical etch for interface engineering in Cu2ZnSnSe4 solar cells |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
| |
Volume |
7 |
Issue |
7 |
Pages |
14690-14698 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The removal of secondary phases from the surface of the kesterite crystals is one of the major challenges to improve the performances of Cu2ZnSn(S,Se)(4) (CZTSSe) thin film solar cells. In this Contribution, the KCN/KOH Chemical etching approach, originally developed for the removal of CuxSe phases in Cu(In,Ga)(S,Se)(2) thin films) is applied to CZTSe absorbers exhibiting various chemical compositions. Two distinct electrical behaviors were observed on CZTSe/CdS solar cells after treatment: (i) the improvement of the fill factor (FF) after 30 s of etching for the CZTSe absorbers showing initially a distortion of the electrical characteristic; (ii) the progressive degradation Of the FF after long treatment time for all Cu-poor CZTSe solar cell samples. The first effect can be attributed to the action of KCN on the absorber, that is found to clean the absorber free surface from most of the secondary phases surrounding the kesterite grains (e.g., Se-0, CuxSe, SnSex, SnO2, Cu2SnSe3 phases, excepting the ZnSe-based phases). The second observation was identified as a consequence of the preferential etching of Se, Sn, and Zn from the CZTSe surface by the KOH solution, combined with the modification of the alkali content of the absorber. The formation of a Cu-rich shell at the absorber/buffer layer interface, leading to the increase of the recombination rate at the interface, and the increase in the doping of the absorber layer after etching are found to be at the origin of the deterioration of the FF of the solar cells. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000358395200019 |
Publication Date |
2015-06-03 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1944-8244;1944-8252; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
7.504 |
Times cited |
34 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 7.504; 2015 IF: 6.723 |
| |
Call Number |
c:irua:127153 |
Serial |
1755 |
| Permanent link to this record |
| |
|
| |
|
Author |
Quintana, M.; López, A.M.; Rapino, S.; Toma, F.M.; Iurlo, M.; Carraro, M.; Sartorel, A.; Maccato, C.; Ke, X.; Bittencourt, C.; Da Ros, T.; Van Tendeloo, G.; Marcaccio, M.; Paolucci, F.; Prato, M.; Bonchio, M.; |
| |
Title |
Knitting the catalytic pattern of artificial photosynthesis to a hybrid graphene nanotexture |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
| |
Volume |
7 |
Issue |
1 |
Pages |
811-817 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The artificial leaf project calls for new materials enabling multielectron catalysis with minimal overpotential, high turnover frequency, and long-term stability. Is graphene a better material than carbon nanotubes to enhance water oxidation catalysis for energy applications? Here we show that functionalized graphene with a tailored distribution of polycationic, quaternized, ammonium pendants provides an sp(2) carbon nanoplatform to anchor a totally inorganic tetraruthenate catalyst, mimicking the oxygen evolving center of natural PSII. The resulting hybrid material displays oxygen evolution at overpotential as low as 300 mV at neutral pH with negligible loss of performance after 4 h testing. This multilayer electroactive asset enhances the turnover frequency by 1 order of magnitude with respect to the isolated catalyst, and provides a definite up-grade of the carbon nanotube material, with a similar surface functionalization. Our innovation is based on a noninvasive, synthetic protocol for graphene functionalization that goes beyond the ill-defined oxidation-reduction methods, allowing a definite control of the surface properties. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000314082800088 |
Publication Date |
2012-12-17 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.942 |
Times cited |
69 |
Open Access |
|
| |
Notes |
246791 COUNTATOMS; 262348 ESMI; ESF Cost Action NanoTP MP0901 |
Approved |
Most recent IF: 13.942; 2013 IF: 12.033 |
| |
Call Number |
UA @ lucian @ c:irua:107707 |
Serial |
1766 |
| Permanent link to this record |
| |
|
| |
|
Author |
Barbier, M.; Vasilopoulos, P.; Peeters, F.M. |
| |
Title |
Kronig-Penney model on bilayer graphene : spectrum and transmission periodic in the strength of the barriers |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
23 |
Pages |
235408-235408,10 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
We show that the transmission through single and double δ-function potential barriers of strength P=VWb/ℏvF in bilayer graphene is periodic in P with period π. For a certain range of P values we find states that are bound to the potential barrier and that run along the potential barrier. Similar periodic behavior is found for the conductance. The spectrum of a periodic succession of δ-function barriers (Kronig-Penney model) in bilayer graphene is periodic in P with period 2π. For P smaller than a critical value Pc, the spectrum exhibits two Dirac points while for P larger than Pc an energy gap opens. These results are extended to the case of a superlattice of δ-function barriers with P alternating in sign between successive barriers; the corresponding spectrum is periodic in P with period π. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000286766900008 |
Publication Date |
2010-12-06 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
34 |
Open Access |
|
| |
Notes |
; This work was supported by IMEC, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the Canadian NSERC under Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:88910 |
Serial |
1768 |
| Permanent link to this record |
| |
|
| |
|
Author |
Yang, C.H.; Peeters, F.M.; Xu, W. |
| |
Title |
Landau-level broadening due to electron-impurity interaction in graphene in strong magnetic fields |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
7 |
Pages |
075401:1-075401:6 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The effect of electron-impurity and electron-electron interactions on the energy spectrum of electrons moving in graphene is investigated in the presence of a high magnetic field. We find that the width of the broadened Landau levels exhibits an approximate 1/B dependence near half filling for charged impurity scattering. The Landau-level width, the density of states, and the Fermi energy exhibit an oscillatory behavior as a function of magnetic field. Comparison with experiment shows that scattering with charged impurities cannot be the main scattering mechanism that determines the width of the Landau levels. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000280553700008 |
Publication Date |
2010-08-04 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the National Science Foundation of China under Grant No. 10804053, the Foundation of NUIST under Grant No. S8108062001, and the Chinese Academy of Sciences and Department of Science and Technology of Yunnan Province. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:84043 |
Serial |
1769 |
| Permanent link to this record |
| |
|
| |
|
Author |
Sena, S.H.R.; Pereira, J.M.; Peeters, F.M.; Farias, G.A. |
| |
Title |
Landau levels in asymmetric graphene trilayer |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
84 |
Issue |
20 |
Pages |
205448-205448,7 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The electronic spectrum of three coupled graphene layers (graphene trilayers) is investigated in the presence of an external magnetic field. We obtain analytical expressions for the Landau level spectrum for both the ABA and ABC type of stacking, which exhibit very different dependence on the magnetic field. We show that layer asymmetry and an external gate voltage can strongly influence the properties of the system. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000297295400018 |
Publication Date |
2011-11-21 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
30 |
Open Access |
|
| |
Notes |
; This work was supported by the Brazilian Council for Research (CNPq), the National Council for the Improvement of Higher Education (CAPES), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral projects between Flanders and Brazil and the CNPq and FWO-Vl. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| |
Call Number |
UA @ lucian @ c:irua:94026 |
Serial |
1773 |
| Permanent link to this record |
| |
|
| |
|
Author |
Mazo, G.N.; Savvin, S.N.; Abakumov, A.M.; Hadermann, J.; Dobrovol'skii, Y.A.; Leonova, L.S. |
| |
Title |
Lanthanum-strontium cuprate as a promising cathodic matreila for solid oxide fuel cells |
Type |
A1 Journal article |
| |
Year |
2007 |
Publication |
Russian journal of electrochemistry |
Abbreviated Journal |
Russ J Electrochem+ |
| |
Volume |
43 |
Issue |
4 |
Pages |
436-442 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
|
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000246338500010 |
Publication Date |
2007-05-09 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1023-1935;1608-3342; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
0.828 |
Times cited |
8 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 0.828; 2007 IF: 0.263 |
| |
Call Number |
UA @ lucian @ c:irua:62062 |
Serial |
1777 |
| Permanent link to this record |
| |
|
| |
|
Author |
Neek-Amal, M.; Peeters, F.M. |
| |
Title |
Lattice thermal properties of graphane : thermal contraction, roughness, and heat capacity |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
83 |
Issue |
23 |
Pages |
235437-235437,6 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Using atomistic simulations, we determine the roughness and the thermal properties of a suspended graphane sheet. As compared to graphene, we found that (i) hydrogenated graphene has a larger thermal contraction, (ii) the roughness exponent at room temperature is smaller, i.e., ≃ 1.0 versus ≃ 1.2 for graphene, (iii) the wavelengths of the induced ripples in graphane cover a wide range corresponding to length scales in the range 30125 Å at room temperature, and (iv) the heat capacity of graphane is estimated to be 29.32±0.23 J/mol K, which is 14.8% larger than that for graphene, i.e., 24.98±0.14 J/mol K. Above 1500 K, we found that graphane buckles when its edges are supported in the x-y plane. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000292253400011 |
Publication Date |
2011-06-30 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
42 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| |
Call Number |
UA @ lucian @ c:irua:90921 |
Serial |
1803 |
| Permanent link to this record |
| |
|
| |
|
Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Sheptyakov, D.V.; Frontzek, M.; Hadermann, J.; Abakumov, A.M. |
| |
Title |
Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| |
Volume |
27 |
Issue |
27 |
Pages |
2946-2956 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000353865800028 |
Publication Date |
2015-03-26 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
9.466 |
Times cited |
11 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
| |
Call Number |
c:irua:126060 |
Serial |
1807 |
| Permanent link to this record |
| |
|
| |
|
Author |
Quintana, M.; Ke, X.; Van Tendeloo, G.; Meneghetti, M.; Bittencourt, C.; Prato, M. |
| |
Title |
Light-induced selective deposition of Au nanoparticles on single-wall carbon nanotubes |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
| |
Volume |
4 |
Issue |
10 |
Pages |
6105-6113 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| |
Abstract |
Novel applications of single-walled carbon nanotubes (SWNT) rely on the development of new strategies to make them easier to handle without affecting their structural properties. In this work, we have selectively deposited Au nanoparticles (Au NP) on SWNT assisted by UV light irradiation. XPS analysis and UV-vis spectroscopy indicate that the deposition occurs at the defects generated after oxidation of the SWNT. By addition of n-dodecylthiol, the separation of oxidized tubes with Au NP (Au-ox-SWNT) from tubes devoid of Au NP (bare tubes, b-SWNT) was achieved. Raman and UV-vis-NIR spectra indicate that UV irradiation induces a faster nucleation of Au NP on metallic SWNT. This new technique can be useful for the preparation of nanohybrid composites with enhanced properties, as increased thermal stability, and to obtain purified SWNT. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000283453700081 |
Publication Date |
2010-09-24 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.942 |
Times cited |
26 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 13.942; 2010 IF: 9.865 |
| |
Call Number |
UA @ lucian @ c:irua:99202 |
Serial |
1819 |
| Permanent link to this record |
| |
|
| |
|
Author |
Neek-Amal, M.; Peeters, F.M. |
| |
Title |
Linear reduction of stiffness and vibration frequencies in defected circular monolayer graphene |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
81 |
Issue |
23 |
Pages |
11 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
|
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000279336000001 |
Publication Date |
2010-06-29 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
44 |
Open Access |
|
| |
Notes |
; Financial support was provided by the Hungarian Research Foundation (Contracts No. OTKA K68312, No. K77771, No. K73361, and No. F68726). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:83857 |
Serial |
1820 |
| Permanent link to this record |
| |
|
| |
|
Author |
Li, J.; Ji, M.; Schwarz, T.; Ke, X.; Van Tendeloo, G.; Yuan, J.; Pereira, P.J.; Huang, Y.; Zhang, G.; Feng, H.L.; Yuan, Y.H.; Hatano, T.; Kleiner, R.; Koelle, D.; Chibotaru, L.F.; Yamaura, K.; Wang, H.B.; Wu, P.H.; Takayama-Muromachi, E.; Vanacken, J.; Moshchalkov, V.V.; |
| |
Title |
Local destruction of superconductivity by non-magnetic impurities in mesoscopic iron-based superconductors |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| |
Volume |
6 |
Issue |
6 |
Pages |
7614 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The determination of the pairing symmetry is one of the most crucial issues for the iron-based superconductors, for which various scenarios are discussed controversially. Non-magnetic impurity substitution is one of the most promising approaches to address the issue, because the pair-breaking mechanism from the non-magnetic impurities should be different for various models. Previous substitution experiments demonstrated that the non-magnetic zinc can suppress the superconductivity of various iron-based superconductors. Here we demonstrate the local destruction of superconductivity by non-magnetic zinc impurities in Ba0.5K0.5Fe2As2 by exploring phase-slip phenomena in a mesoscopic structure with 119 × 102 nm2 cross-section. The impurities suppress superconductivity in a three-dimensional Swiss cheese-like pattern with in-plane and out-of-plane characteristic lengths slightly below ~1.34 nm. This causes the superconducting order parameter to vary along abundant narrow channels with effective cross-section of a few square nanometres. The local destruction of superconductivity can be related to Cooper pair breaking by non-magnetic impurities. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000358857000007 |
Publication Date |
2015-07-03 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2041-1723; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
12.124 |
Times cited |
12 |
Open Access |
|
| |
Notes |
246791 Countatoms |
Approved |
Most recent IF: 12.124; 2015 IF: 11.470 |
| |
Call Number |
c:irua:126677 |
Serial |
1827 |
| Permanent link to this record |
| |
|
| |
|
Author |
Tsvyashchenko, A.V.; Nikolaev, A.V.; Velichkov, A.I.; Salamatin, A.V.; Fomicheva, L.N.; Ryasny, G.K.; Sorokin, A.A.; Kochetov, O.I.; Budzynski, M.; Michel, K.H. |
| |
Title |
Lowering of the spatial symmetry at the gamma ->alpha phase transition in cerium |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
82 |
Issue |
9 |
Pages |
1-4 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient (EFG) at 111Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic α phase is almost four times larger than in the cubic γ phase and close to values in the noncubic phases α′ and α″. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the γ→α transition while the lattice remains face-centered cubic |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000282004400001 |
Publication Date |
2010-09-16 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
| |
Notes |
; This work is supported by the Program of the Presidium of the Russian Academy of Sciences “Physics of Strongly Compressed Matter.” We are grateful to S. M. Stishov, B. Verberck, A. N. Grum-Grzhimailo, V. B. Brudanin and G. Heger for support of this work and discussion of the results. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| |
Call Number |
UA @ lucian @ c:irua:85464 |
Serial |
1854 |
| Permanent link to this record |
| |
|
| |
|
Author |
Tikhomirov, V.K.; Vosch, T.; Fron, E.; Rodríguez, V.D.; Velázquez, J.J.; Kirilenko, D.; Van Tendeloo, G.; Hofkens, J.; Van der Auweraer, M.; Moshchalkov, V.V. |
| |
Title |
Luminescence of oxyfluoride glasses co-doped with Ag nanoclusters and Yb3+ ions |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
| |
Volume |
2 |
Issue |
4 |
Pages |
1496-1501 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
Bulk oxyfluoride glasses co-doped with Ag nanoclusters and Yb3+ ions have been prepared by a melt quenching technique. When excited in the absorption band of the Ag nanoclusters between 300 to 500 nm, these glasses emit a broad band characteristic of the Ag nanoclusters between 400 to 750 nm as well as an emission band between 900 to 1100 nm, originating from Yb3+ ions. The intensity ratio of the Yb3+/Ag emission bands increases with the Ag doping level at a fixed concentration of Yb3+, indicating the presence of energy transfer mechanism from the Ag nanoclusters to the Yb3+ ions. Comparison of time-resolved decay kinetics of the luminescence in the respectively Ag nanocluster-Yb3+ co-doped and single Ag nanocluster doped glasses, hints towards an energy transfer from the red and infrared emitting Ag nanoclusters to the Yb3+ ions. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000299695300038 |
Publication Date |
2011-12-19 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2046-2069; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.108 |
Times cited |
46 |
Open Access |
|
| |
Notes |
Fwo; Iap |
Approved |
Most recent IF: 3.108; 2012 IF: 2.562 |
| |
Call Number |
UA @ lucian @ c:irua:96239 |
Serial |
1856 |
| Permanent link to this record |
| |
|
| |
|
Author |
Walter, A.L.; Sahin, H.; Jeon, K.J.; Bostwick, A.; Horzum, S.; Koch, R.; Speck, F.; Ostler, M.; Nagel, P.; Merz, M.; Schupler, S.; Moreschini, L.; Chang, Y.J.; Seyller, T.; Peeters, F.M.; Horn, K.; Rotenberg, E.; |
| |
Title |
Luminescence, patterned metallic regions, and photon-mediated electronic changes in single-sided fluorinated graphene sheets |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
| |
Volume |
8 |
Issue |
8 |
Pages |
7801-7808 |
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| |
Abstract |
Single-sided fluorination has been predicted to open an electronic band gap in graphene and to exhibit unique electronic and magnetic properties; however, this has not been substantiated by experimental reports. Our comprehensive experimental and theoretical study of this material on a SiC(0001) substrate shows that single-sided fluorographene exhibits two phases, a stable one with a band gap of similar to 6 eV and a metastable one, induced by UV irradiation, with a band gap of similar to 2.5 eV. The metastable structure, which reverts to the stable “ground-state” phase upon annealing under emission of blue light, in our view is induced by defect states, based on the observation of a nondispersive electronic state at the top of the valence band, not unlike that found in organic molecular layers. Our structural data show that the stable C2F ground state has a “boat” structure, in agreement with our X-ray magnetic circular dichroism data, which show the absence of an ordered magnetic phase. A high flux of UV or X-ray photons removes the fluorine atoms, demonstrating the possibility of lithographically patterning conducting regions into an otherwise semiconducting 2D material. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000340992300025 |
Publication Date |
2014-08-09 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.942 |
Times cited |
23 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 13.942; 2014 IF: 12.881 |
| |
Call Number |
UA @ lucian @ c:irua:119263 |
Serial |
1857 |
| Permanent link to this record |
| |
|
| |
|
Author |
Tahir, M.; Vasilopoulos, P.; Peeters, F.M. |
| |
Title |
Magneto-optical transport properties of monolayer phosphorene |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
92 |
Issue |
92 |
Pages |
045420 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
The electronic properties of monolayer phosphorene are exotic due to its puckered structure and large intrinsic direct band gap. We derive and discuss its band structure in the presence of a perpendicular magnetic field. Further, we evaluate the magneto-optical Hall and longitudinal optical conductivities as functions of temperature, magnetic field, and Fermi energy, and show that they are strongly influenced by the magnetic field. The imaginary part of the former and the real part of the latter exhibit regular interband oscillations as functions of the frequency omega in the range (h) over bar omega similar to 1.5-2 eV. Strong intraband responses in the latter and weak ones in the former occur at much lower frequencies. The magneto-optical response can be tuned in the microwave-to-terahertz and visible frequency ranges in contrast with a conventional two-dimensional electron gas or graphene in which the response is limited to the terahertz regime. This ability to isolate carriers in an anisotropic structure may make phosphorene a promising candidate for new optical devices. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000358373600003 |
Publication Date |
2015-07-23 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
68 |
Open Access |
|
| |
Notes |
; This work was supported by the the Canadian NSERC Grant No. OGP0121756 (M.T., P.V.) and by the Flemish Science Foundation (FWO-Vl) (F.M.P.). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
| |
Call Number |
c:irua:127192 |
Serial |
1903 |
| Permanent link to this record |
| |
|
| |
|
Author |
Kálmán, O.; Földi, P.; Benedict, M.G.; Peeters, F.M. |
| |
Title |
Magnetoconductance of rectangular arrays of quantum rings |
Type |
A1 Journal article |
| |
Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
78 |
Issue |
12 |
Pages |
125306-125306,10 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Electron transport through multiterminal rectangular arrays of quantum rings is studied in the presence of Rashba-type spin-orbit interaction (SOI) and of a perpendicular magnetic field. Using the analytic expressions for the transmission and reflection coefficients for single rings we obtain the conductance through such arrays as a function of the SOI strength, of the magnetic flux, and of the wave vector k of the incident electron. Due to destructive or constructive spin interferences caused by the SOI, the array can be totally opaque for certain ranges of k, while there are parameter values where it is completely transparent. Spin resolved transmission probabilities show nontrivial spin transformations at the outputs of the arrays. When pointlike random scattering centers are placed between the rings, the Aharonov-Bohm peaks split, and an oscillatory behavior of the conductance emerges as a function of the SOI strength. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000259691500047 |
Publication Date |
2008-09-05 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
| |
Call Number |
UA @ lucian @ c:irua:94598 |
Serial |
1913 |
| Permanent link to this record |
| |
|
| |
|
Author |
Veljkovic, D.; Tadić, M.; Peeters, F.M. |
| |
Title |
Magnetoexcitons in type-II self-assembled quantum dots and quantum-dot superlattices |
Type |
A1 Journal article |
| |
Year |
2006 |
Publication |
Recent developments in advanced materials and processes |
Abbreviated Journal |
|
| |
Volume |
518 |
Issue |
|
Pages |
51-56 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
|
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; |
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:60841 |
Serial |
1918 |
| Permanent link to this record |
| |
|
| |
|
Author |
Çakir, D.; Otalvaro, D.M.; Brocks, G. |
| |
Title |
Magnetoresistance in multilayer fullerene spin valves: A first-principles study |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
90 |
Issue |
24 |
Pages |
245404 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Carbon-based molecular semiconductors are explored for application in spintronics because their small spinorbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi-and tri-layers of the fullerene molecules C-60 and C-70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP > 90%) and magnetoresistance (MR > 100%) at small bias can be attained using C-70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C-60 layers. Exploiting a generalized Julliere model we can trace the differences in spin-dependent transport between C-60 and C-70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000345875200005 |
Publication Date |
2014-12-02 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| |
Call Number |
UA @ lucian @ c:irua:122177 |
Serial |
1928 |
| Permanent link to this record |
| |
|
| |
|
Author |
Berdiyorov, G.R.; Chao, X.H.; Peeters, F.M.; Wang, H.B.; Moshchalkov, V.V.; Zhu, B.Y. |
| |
Title |
Magnetoresistance oscillations in superconducting strips : a Ginzburg-Landau study |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
86 |
Issue |
22 |
Pages |
224504-224508 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Within the time-dependent Ginzburg-Landau theory we study the dynamic properties of current-carrying superconducting strips in the presence of a perpendicular magnetic field. We found pronounced voltage peaks as a function of the magnetic field, the amplitude of which depends both on sample dimensions and external parameters. These voltage oscillations are a consequence of moving vortices, which undergo alternating static and dynamic phases. At higher fields or for high currents, the continuous motion of vortices is responsible for the monotonic background on which the resistance oscillations due to the entry of additional vortices are superimposed. Mechanisms for such vortex-assisted resistance oscillations are discussed. Qualitative changes in the magnetoresistance curves are observed in the presence of random defects, which affect the dynamics of vortices in the system. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000312064300004 |
Publication Date |
2012-12-10 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the ESF-NES program. G. R. B. acknowledges support from FWO-Vl. B.Y.Z. acknowledges the support from the MOST 973 Projects No. 2011CBA00110 and No. 2009CB930803, and the National Natural Science Foundation of China. V. V. M. acknowledges support from the Methusalem Funding by the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| |
Call Number |
UA @ lucian @ c:irua:105969 |
Serial |
1930 |
| Permanent link to this record |
| |
|
| |
|
Author |
van der Burgt, M.; Karavolas, V.C.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; Van Hove, M.; Borghs, G. |
| |
Title |
Magnetotransport in a pseudomorphic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure with a Si \delta-doping layer |
Type |
A1 Journal article |
| |
Year |
1995 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
52 |
Issue |
16 |
Pages |
12218-12231 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Magnetotransport properties of a pseudomorphic GsAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T = 1.4 and 4.2 K. The structure studied consists of a Si delta layer parallel to a Ga0.8In0.2As quantum well (QW). The dark electron density of the structure is n(c) = 1.67 x 10(16) m(-2). By illumination the density can be increased up to a factor of 4; this way the second subband in the Ga0.08In0.2As QW can become populated as well as the Si delta layer. The presence of electrons in the delta layer results in drastic changes in the transport data, especially at magnetic fields beyond 30 T. The phenomena observed are interpreted as (i) magnetic freeze-out of carriers in the delta layer when a low density of electrons is present in the delta layer, and (ii) quantization of the electron motion in the two-dimensional electron gases in both the Ga0.8In0.2As QW and the Si delta layer in the case of high densities. These conclusions are corroborated by the numerical results of our theoretical model. We obtain satisfactory agreement between model and experiment. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
A1995TB96600102 |
Publication Date |
2002-07-27 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.736 |
Times cited |
43 |
Open Access |
|
| |
Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
| |
Call Number |
UA @ lucian @ c:irua:99708 |
Serial |
1933 |
| Permanent link to this record |
| |
|
| |
|
Author |
Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. |
| |
Title |
Magnetotransport in periodically modulated bilayer graphene |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
85 |
Issue |
24 |
Pages |
245426-245426,10 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Magnetotransport in bilayer graphene in the presence of a weak and periodic potential is investigated in the presence of a perpendicular magnetic field B. The modulation broadens the Landau levels into bands and for weak magnetic fields leads to the well-known Weiss oscillations in their bandwidth and their transport coefficients at very low B and to the Shubnikov-de Haas oscillations at larger B. The amplitude of the Weiss oscillations is severely reduced if the periodic potentials applied to the two layers oscillate out of phase. We also contrast some results with those corresponding to single-layer graphene. Relative to them the flat-band condition and the oscillation amplitude differ substantially, due to the interlayer coupling, and agree only when this coupling is extremely weak. We further show that the Hall conductivity exhibits the well-known steps at half-integer and integer multiples of 4e(2)/h in single-layer and bilayer graphene, respectively, even for very weak magnetic fields. The results are pertinent to weak and periodic corrugations when the potential modulation dominates the strain-induced magnetic modulation. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000305253600012 |
Publication Date |
2012-06-14 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CON-GRAN), and the Canadian NSERC Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| |
Call Number |
UA @ lucian @ c:irua:99077 |
Serial |
1934 |
| Permanent link to this record |
| |
|
| |
|
Author |
Zha, G.-Q.; Covaci, L.; Peeters, F.M.; Zhou, S.-P. |
| |
Title |
Majorana fermion states and fractional flux periodicity in mesoscopic d-wave superconducting loops with spin-orbit interaction |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
90 |
Issue |
1 |
Pages |
014522 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
We numerically investigate the spin-orbit (SO) coupling effect on the magnetic flux evolution of energy and supercurrent in mesoscopic d-wave superconducting loops by solving the spin-generalized Bogoliubov-de Gennes equations self-consistently. It is found that the energy spectrum splits when the SO interaction is involved and the Majorana zero mode can be realized in the [100] edges of square systems for an appropriate SO coupling strength. Superconducting phase transitions appear when the energy gap closes, accompanied by energy jumps between different energy parabolas in the ground state, which provides a possible mechanism to support fractional flux periodicity of supercurrent. Moreover, in the case of rectangular loops with SO coupling, the jumps of the ground-state energy gradually disappear by increasing the ratio of length to height of the sample, and a paramagnetic response with opposite direction of the screening current around zero flux value can occur in such systems. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000341233800010 |
Publication Date |
2014-07-31 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| |
Notes |
; This work was supported by National Natural Science Foundation of China under Grants No. 61371020 and No. 61271163, by Visiting Scholar Program of Shanghai Municipal Education Commission, by Innovation Program of Shanghai Municipal Education Commission under Grant No. 13YZ006, and by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| |
Call Number |
UA @ lucian @ c:irua:119266 |
Serial |
1938 |
| Permanent link to this record |
| |
|
| |
|
Author |
Felten, A.; Gillon, X.; Gulas, M.; Pireaux, J.-J.; Ke, X.; Van Tendeloo, G.; Bittencourt, C.; Najafi, E.; Hitchcock, A.P. |
| |
Title |
Measuring point defect density in individual carbon nanotubes using polarization-dependent X-ray microscopy |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
| |
Volume |
4 |
Issue |
8 |
Pages |
4431-4436 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| |
Abstract |
The presence of defects in carbon nanotubes strongly modifies their electrical, mechanical, and chemical properties. It was long thought undesirable, but recent experiments have shown that introduction of structural defects using ion or electron irradiation can lead to novel nanodevices. We demonstrate a method for detecting and quantifying point defect density in individual carbon nanotubes (CNTs) based on measuring the polarization dependence (linear dichroism) of the C 1s → π* transition at specific locations along individual CNTs with a scanning transmission X-ray microscope (STXM). We show that STXM can be used to probe defect density in individual CNTs with high spatial resolution. The quantitative relationship between ion dose, nanotube diameter, and defect density was explored by purposely irradiating selected sections of nanotubes with kiloelectronvolt (keV) Ga+ ions. Our results establish polarization-dependent X-ray microscopy as a new and very powerful characterization technique for carbon nanotubes and other anisotropic nanostructures. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000281052700014 |
Publication Date |
2010-07-07 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
13.942 |
Times cited |
26 |
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 13.942; 2010 IF: 9.865 |
| |
Call Number |
UA @ lucian @ c:irua:84734 |
Serial |
1966 |
| Permanent link to this record |
| |
|
| |
|
Author |
Singh, S.K.; Neek-Amal, M.; Peeters, F.M. |
| |
Title |
Melting of graphene clusters |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
87 |
Issue |
13 |
Pages |
134103-134109 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Density-functional tight-binding and classical molecular dynamics simulations are used to investigate the structural deformations and melting of planar carbon nanoclusters C-N with N = 2-55. The minimum-energy configurations for different clusters are used as starting configurations for the study of the temperature effects on the bond breaking and rotation in carbon lines (N < 6), carbon rings (5 < N < 19), and graphene nanoflakes. The larger the rings (graphene nanoflakes) the higher the transition temperature (melting point) with ring-to-line (perfect-to-defective) transition structures. The melting point was obtained by using the bond energy, the Lindemann criteria, and the specific heat. We found that hydrogen-passivated graphene nanoflakes (CNHM) have a larger melting temperature with a much smaller dependence on size. The edges in the graphene nanoflakes exhibit several different metastable configurations (isomers) during heating before melting occurs. DOI: 10.1103/PhysRevB.87.134103 |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000317390700001 |
Publication Date |
2013-04-11 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
| |
Notes |
; This work was supported by the EU-Marie Curie IIF Postdoctoral Fellowship No. 299855 (for M.N.-A.), the ESF-EuroGRAPHENE Project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| |
Call Number |
UA @ lucian @ c:irua:108467 |
Serial |
1987 |
| Permanent link to this record |
| |
|
| |
|
Author |
Neek-Amal, M.; Xu, P.; Qi, D.; Thibado, P.M.; Nyakiti, L.O.; Wheeler, V.D.; Myers-Ward, R.L.; Eddy, C.R.; Gaskill, D.K.; Peeters, F.M. |
| |
Title |
Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
90 |
Issue |
6 |
Pages |
064101 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Twisted graphene layers produce a moire pattern (MP) structure with a predetermined wavelength for a given twist angle. However, predicting the membrane corrugation amplitude for any angle other than pure AB-stacked or AA-stacked graphene is impossible using first-principles density functional theory (DFT) due to the large supercell. Here, within elasticity theory, we define the MP structure as the minimum-energy configuration, thereby leaving the height amplitude as the only unknown parameter. The latter is determined from DFT calculations for AB-and AA-stacked bilayer graphene in order to eliminate all fitting parameters. Excellent agreement with scanning tunneling microscopy results across multiple substrates is reported as a function of twist angle. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000339995800001 |
Publication Date |
2014-08-01 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
12 |
Open Access |
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoctoral Fellowship No. 299855. P.M.T. is thankful for the financial support of the Office of Naval Research under Grant No. N00014-10-1-0181 and the National Science Foundation under Grant No. DMR-0855358. L.O.N. acknowledges the support of the American Society for Engineering Education and Naval Research Laboratory Postdoctoral Fellow Program. Work at the US Naval Research Laboratory is supported by the Office of Naval Research. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| |
Call Number |
UA @ lucian @ c:irua:118774 |
Serial |
1991 |
| Permanent link to this record |
| |
|
| |
|
Author |
Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M. |
| |
Title |
Metallic nanograins : spatially nonuniform pairing induced by quantum confinement |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| |
Volume |
83 |
Issue |
21 |
Pages |
214509-214509,12 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
It is well known that the formation of discrete electron levels strongly influences the pairing in metallic nanograins. Here, we focus on another effect of quantum confinement in superconducting grains that was not studied previously, i.e., spatially nonuniform pairing. This effect is very significant when single-electron levels form bunches and/or a kind of shell structure. We find that, in highly symmetric grains, the order parameter can exhibit variations with position by an order of magnitude. Nonuniform pairing is closely related to a quantum-confinement-induced modification of the pairing-interaction matrix elements and size-dependent pinning of the chemical potential to groups of degenerate or nearly degenerate levels. For illustrative purposes, we consider spherical metallic nanograins and also rectangular shapes. We show that the relevant matrix elements are, as a rule, enhanced in the presence of quantum confinement, which favors spatial variations of the order parameter, compensating the corresponding energy cost. The size-dependent pinning of the chemical potential further increases the spatial variation of the pair condensate. The role of nonuniform pairing is smaller in less symmetric confining geometries and/or in the presence of disorder. However, it always remains of importance when the energy spacing between discrete electron levels δ is approaching the scale of the bulk gap ΔB, i.e., δ>0.10.2 ΔB. |
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000291310000006 |
Publication Date |
2011-06-06 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| |
Impact Factor |
3.836 |
Times cited |
23 |
Open Access |
|
| |
Notes |
; This work was supported by the Alexander von Humboldt Foundation, the Flemish Science Foundation (FWO-VI), and the Belgian Science Policy (IAP). M. D. C. acknowledges support of the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| |
Call Number |
UA @ lucian @ c:irua:90081 |
Serial |
2010 |
| Permanent link to this record |
| |
|
| |
|
Author |
Verbist, K.; Tafuri, F.; Granozio, F.M.; Di Chiara, S.; Van Tendeloo, G. |
| |
Title |
Microstructure of artificial [100] 45 degrees twist grain boundaries in YBa2Cu3O7-delta |
Type |
P1 Proceeding |
| |
Year |
1998 |
Publication |
Electron Microscopy 1998, Vol 2: Materials Science 1 |
Abbreviated Journal |
|
| |
Volume |
|
Issue |
|
Pages |
593-594 |
| |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
| |
Abstract |
|
| |
Address |
|
| |
Corporate Author |
|
Thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
| |
Language |
|
Wos |
000077019900291 |
Publication Date |
0000-00-00 |
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0-7503-0565-7 |
ISBN |
|
Additional Links |
UA library record; WoS full record; |
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
| |
Call Number |
UA @ lucian @ c:irua:104356 |
Serial |
2066 |
| Permanent link to this record |
