Records |
Author |
Verlooy, P.; Aerts, A.; Lebedev, O.I.; Van Tendeloo, G.; Kirschhock, C.; Martens, J.A. |
Title |
Synthesis of highly stable pure-silica thin-walled hexagonally ordered mesoporous material |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
Volume |
|
Issue |
28 |
Pages |
4287-4289 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Hexagonally ordered mesoporous silica with a very narrow mesopore size distribution and exceptionally high stability paired with unusually thin pore walls was prepared using piperidine and cetyltrimethylammonium bromide. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000267808000040 |
Publication Date |
2009-06-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-7345;1364-548X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.319 |
Times cited |
17 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.319; 2009 IF: 5.504 |
Call Number |
UA @ lucian @ c:irua:77684 |
Serial |
3457 |
Permanent link to this record |
|
|
|
Author |
Tirry, W.; Schryvers, D. |
Title |
Linking a completely three-dimensional nanostrain to a structural transformation eigenstrain |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
Volume |
8 |
Issue |
9 |
Pages |
752-757 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
NiTi is one of the most popular shape-memory alloys, a phenomenon resulting from a martensitic transformation. Commercial NiTi-based alloys are often thermally treated to contain Ni4Ti3 precipitates. The presence of these precipitates can introduce an extra transformation step related to the so-called R-phase. It is believed that the strain field surrounding the precipitates, caused by the matrixprecipitate lattice mismatch, lies at the origin of this intermediate transformation step. Atomic-resolution transmission electron microscopy in combination with geometrical phase analysis is used to measure the elastic strain field surrounding these precipitates. By combining measurements from two different crystallographic directions, the three-dimensional strain matrix is determined from two-dimensional measurements. Comparison of the measured strain matrix to the eigenstrain of the R-phase shows that both are very similar and that the introduction of the R-phase might indeed compensate the elastic strain introduced by the precipitate. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000269215500022 |
Publication Date |
2009-06-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1476-1122;1476-4660; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
39.737 |
Times cited |
53 |
Open Access |
|
Notes |
Multimat |
Approved |
Most recent IF: 39.737; 2009 IF: 29.504 |
Call Number |
UA @ lucian @ c:irua:77657 |
Serial |
1822 |
Permanent link to this record |
|
|
|
Author |
Malard, B.; Pilch, J.; Sittner, P.; Gartnerova, V.; Delville, R.; Schryvers, D.; Curfs, C. |
Title |
Microstructure and functional property changes in thin Ni-Ti wires heat teated by electric current: high energy X-ray and TEM investigations |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Functional materials letters |
Abbreviated Journal |
Funct Mater Lett |
Volume |
2 |
Issue |
2 |
Pages |
45-54 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
High energy synchrotron X-ray diffraction, transmission electron microscopy and mechanical testing were employed to investigate the evolution of microstructure, texture and functional superelastic properties of 0.1 mm thin as drawn NiTi wires subjected to a nonconventional heat treatment by controlled electric current (FTMT-EC method). As drawn NiTi wires were prestrained in tension and exposed to a sequence of short DC power pulses in the millisecond range. The annealing time in the FTMT-EC processing can be very short but the temperature and force could be very high compared to the conventional heat treatment of SMAs. It is shown that the heavily strained, partially amorphous microstructure of the as drawn NiTi wire transforms under the effect of the DC pulse and tensile stress into a wide range of annealed nanosized microstructures depending on the pulse time. The functional superelastic properties and microstructures of the FTMT-EC treated NiTi wire are comparable to those observed in straight annealed wires. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000271077000001 |
Publication Date |
2009-07-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1793-6047;1793-7213; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.234 |
Times cited |
21 |
Open Access |
|
Notes |
Multimat |
Approved |
Most recent IF: 1.234; 2009 IF: 2.561 |
Call Number |
UA @ lucian @ c:irua:77656 |
Serial |
2052 |
Permanent link to this record |
|
|
|
Author |
Tian, H.; Schryvers, D.; Mohanchandra, K.P.; Carman, G.P.; van Humbeeck, J. |
Title |
Fabrication and characterization of functionally graded Ni-Ti multilayer thin films |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Functional materials letters |
Abbreviated Journal |
Funct Mater Lett |
Volume |
2 |
Issue |
2 |
Pages |
61-66 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A functionally graded multilayer NiTi thin film was deposited on a SiO2/Si substrate by d.c. sputtering using a ramped heated NiTi alloy target. The stand-alone films were crystallized at 500°C in vacuum better than 10-7 Torr. Transmission electron microscopy micrographs taken along the film cross section show two distinct regions, thin and thick, with weak R and B2 phases, respectively. The film compositions along the thickness were measured and quantified using the standard-less EELSMODEL method. The film deposited during the initial thermal ramp (thin regions) displays an average of 54 at.% Ni while the film deposited at a more elevated target temperature (thick regions) shows about 51 at.% Ni. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000271077000003 |
Publication Date |
2009-07-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1793-6047;1793-7213; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.234 |
Times cited |
9 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 1.234; 2009 IF: 2.561 |
Call Number |
UA @ lucian @ c:irua:77655 |
Serial |
1165 |
Permanent link to this record |
|
|
|
Author |
Papp, G.; Peeters, F.M. |
Title |
Magneto-ballistic transport through micro-structured junctions on a curved two-dimensional electron gas |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
149 |
Issue |
19/20 |
Pages |
778-780 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate theoretically the ballistic transport in a two-dimensional electron gas, which is rolled up as a tube and is micro-structured into a Hall bar. A uniform magnetic field applied to such a curved surface results in a non-uniform perpendicular magnetic field. The bend resistances become asymmetric with respect to the orientation of the magnetic field due to the varying magnetic field along the junction. The resistance asymmetry is strongly affected by corrugation due to the varying mobility along different crystallographic directions. We compare our results with a recent transport measurement. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000266149900011 |
Publication Date |
2009-03-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.554 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.554; 2009 IF: 1.837 |
Call Number |
UA @ lucian @ c:irua:77580 |
Serial |
1897 |
Permanent link to this record |
|
|
|
Author |
Cao, S.; Tirry, W.; van den Broek, W.; Schryvers, D. |
Title |
3D reconstruction of Ni4Ti3 precipitates in a Ni51Ti49 alloy in a FIB/SEM dual-beam system |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Materials science forum |
Abbreviated Journal |
|
Volume |
583 |
Issue |
|
Pages |
277-284 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Ni4Ti3 precipitates play an important role in the shape memory and superelastic behaviour of thermo-mechanically treated Ni-Ti material. The 3D morphology and distribution of such precipitates with lenticular shape and rhombohedral atomic structure in the austenitic B2 matrix of a binary Ni-rich Ni-Ti alloy has been elucidated via a slice view procedure in a Dual-Beam FIB/SEM system. With the sequence of cross-section SE images obtained from the SEM, a 3D reconstruction has been achieved after proper alignment and image processing, from which both qualitative and quantitative analysis can be performed. Careful imaging is needed to ensure that all variants of the precipitates are observed with equal probability, regardless sample orientation. Moreover, due to the weak contrast of the precipitates, proper imaging conditions need to be selected to allow for semi-automated image treatment. Finally, a volume ratio of 10.2% for the Ni4Ti3 precipitates could be calculated, summed over all variants, which yields a net composition of Ni50.36Ti49.64 for the matrix, leading to an increase of 113 degrees for the martensitic start temperature Ms. Also, the expected relative orientation of the different variants of the precipitates could be confirmed. In the near future, other quantitative measures on the distribution of the precipitates can be expected. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
Language |
|
Wos |
|
Publication Date |
2009-03-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1662-9752; |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
Multimat; Fwo |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:77454 |
Serial |
16 |
Permanent link to this record |
|
|
|
Author |
Baguer, N.; Georgieva, V.; Calderin, L.; Todorov, I.T.; van Gils, S.; Bogaerts, A. |
Title |
Study of the nucleation and growth of TiO2 and ZnO thin films by means of molecular dynamics simulations |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of crystal growth |
Abbreviated Journal |
J Cryst Growth |
Volume |
311 |
Issue |
16 |
Pages |
4034-4043 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The nucleation and growth of titanium dioxide (TiO2) and zinc oxide (ZnO) thin films on Fe2O3 (hematite), Al2O3 (á-alumina) and SiO2 (á-quartz) are studied by molecular dynamics simulations. The results show the formation of a strong interface region between the substrate and the film in the six systems studied here. A combination of polycrystalline and amorphous phases are observed in the TiO2 films grown on the three substrates. ZnO deposition on the Fe2O3 and Al2O3 crystals yields a monocrystalline film growth. The ZnO film deposited on the SiO2 crystal exhibits less crystallinity. The simulation results are compared with experimental results available in the literature. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000269580100012 |
Publication Date |
2009-06-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-0248; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.751 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.751; 2009 IF: 1.534 |
Call Number |
UA @ lucian @ c:irua:77453 |
Serial |
3338 |
Permanent link to this record |
|
|
|
Author |
Pereira, J.M.; Peeters, F.M.; Vasilopoulos, P.; Costa Filho, R.N.; Farias, G.A. |
Title |
Landau levels in graphene bilayer quantum dots |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
19 |
Pages |
195403,1-195403,5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate localized electron and hole states in parabolic quantum dots of biased graphene bilayers in the presence of a perpendicular magnetic field. These quantum dots can be created by means of nanostructured gates or by position-dependent doping, which can create a gap in the otherwise gapless dispersion of a graphene bilayer. Numerical results show the energy levels of confined electrons and holes as a function of the dot parameters and the magnetic field. Remarkable crossings of energy levels are found. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000266501300102 |
Publication Date |
2009-05-05 |
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 |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77401 |
Serial |
1774 |
Permanent link to this record |
|
|
|
Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
Title |
Kinematic vortex-antivortex lines in strongly driven superconducting stripes |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
19 |
Issue |
18 |
Pages |
184506,1-184506,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In the framework of the time-dependent Ginzburg-Landau formalism, we study the resistive state of a submicron superconducting stripe in the presence of a longitudinal current. Sufficiently strong current leads to phase slippage between the leads, which is manifested as oppositely charged kinematic vortices moving in opposite directions perpendicular to applied drive. Depending on the distribution of superconducting current density the vortex-antivortex either nucleate in the middle of the stripe and are expelled laterally or enter on opposite sides of the sample and are driven together to annihilation. We distinguish between the two scenarios as a function of relevant parameters and show how the creation/annihilation point of the vortex-antivortex and their individual velocity can be manipulated by applied magnetic field and current. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000266501200091 |
Publication Date |
2009-05-06 |
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 |
75 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77400 |
Serial |
1756 |
Permanent link to this record |
|
|
|
Author |
Geurts, R.; Milošević, M.V.; Peeters, F.M. |
Title |
Second generation of vortex-antivortex states in mesoscopic superconductors: stabilization by artificial pinning |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
17 |
Pages |
174508,1-174508,5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Antagonistic symmetries of superconducting polygons and their induced multivortex states in a homogeneous magnetic field may lead to the appearance of antivortices in the vicinity of the superconducting/normal-state boundary (where mesoscopic confinement is particularly strong). Resulting vortex-antivortex (V-Av) molecules match the sample symmetry but are extremely sensitive to defects and fluctuations and remain undetected experimentally. Here we show that V-Av states can reappear deep in the superconducting state due to an array of perforations in a polygonal setting, surrounding a central hole. Such states are no longer caused by the symmetry of the sample but rather by pinning itself, which prevents the vortex-antivortex annihilation. As a result, even micron size, clearly spaced V-Av molecules can be stabilized in large mesoscopic samples. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000266501100098 |
Publication Date |
2009-05-06 |
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 |
17 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77399 |
Serial |
2956 |
Permanent link to this record |
|
|
|
Author |
Berdiyorov, G.R.; Elmurodov, A.K.; Peeters, F.M.; Vodolazov, D.Y. |
Title |
Finite-size effect on the resistive state in a mesoscopic type-II superconducting stripe |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
17 |
Pages |
174506,1-174506,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Within the time-dependent Ginzburg-Landau (TDGL) theory we studied the creation of phase-slip lines and the interplay with a vortex lattice in a finite-length superconducting thin stripe with finite-size normal metal leads. In zero magnetic field and with increasing transport current phase-slip lines appear across the sample leading to distinct jumps in the current-voltage characteristics. When a magnetic field is applied, the moving vortex lattice becomes rearranged by the external current and fast and slow moving vortex channels are formed. Curved vortex channels are observed near the normal contacts. We found the remarkable result that at small applied magnetic field the normal-state transition current is increased as compared to the one at zero magnetic field. This effect is more pronounced for larger values of the parameter in the TDGL formalism. This unusual field-induced increase in the critical current is a consequence of the nonuniform distribution of the current in the sample. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000266501100096 |
Publication Date |
2009-05-05 |
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 |
36 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77398 |
Serial |
1196 |
Permanent link to this record |
|
|
|
Author |
Lin, N.S.; Misko, V.R.; Peeters, F.M. |
Title |
Unconventional vortex dynamics in mesoscopic superconducting corbino disks |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
102 |
Issue |
19 |
Pages |
197003,1-197003,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The discrete shell structure of vortex matter strongly influences the flux dynamics in mesoscopic superconducting Corbino disks. While the dynamical behavior is well understood in large and in very small disks, in the intermediate-size regime it occurs to be much more complex and unusual, due to (in)commensurability between the vortex shells. We demonstrate unconventional vortex dynamics (inversion of shell velocities with respect to the gradient driving force) and angular melting (propagating from the boundary where the shear stress is minimum, towards the center) in mesoscopic Corbino disks. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000266207700063 |
Publication Date |
2009-05-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
Call Number |
UA @ lucian @ c:irua:77396 |
Serial |
3800 |
Permanent link to this record |
|
|
|
Author |
Matulis, A.; Peeters, F.M. |
Title |
Analogy between one-dimensional chain models and graphene |
Type |
A1 Journal article |
Year |
2009 |
Publication |
American journal of physics |
Abbreviated Journal |
Am J Phys |
Volume |
77 |
Issue |
7 |
Pages |
595-601 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The electron and hole spectrum in single and bilayer graphene is derived from known one-dimensional models, and the relation between the spectrum and symmetry of the lattice is shown. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000266976000003 |
Publication Date |
2009-06-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-9505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.069 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.069; 2009 IF: 0.779 |
Call Number |
UA @ lucian @ c:irua:77381 |
Serial |
97 |
Permanent link to this record |
|
|
|
Author |
Payette, C.; Partoens, B.; Yu, G.; Gupta, J.A.; Austing, D.G.; Nair, S.V.; Amaha, S.; Tarucha, S. |
Title |
Modeling single-particle energy levels and resonance currents in a coherent electronic quantum dot mixer |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
94 |
Issue |
22 |
Pages |
222101,1-22101,3 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present model calculations based on a coherent tunneling picture, which reproduce well both the single-particle energy level position and the resonant current strength at two typical anticrossings, one involving two levels and the other three levels in a coherent mixer composed of two weakly coupled vertical quantum dots. An essential ingredient is the inclusion of higher degree terms to account for deviations from an ideal elliptical parabolic confining potential in realistic dots. We also calculate density plots of the mixed states for the modified potential. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000266674300024 |
Publication Date |
2009-06-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2009 IF: 3.554 |
Call Number |
UA @ lucian @ c:irua:77380 |
Serial |
2139 |
Permanent link to this record |
|
|
|
Author |
Eckert, M.; Neyts, E.; Bogaerts, A. |
Title |
Modeling adatom surface processes during crystal growth: a new implementation of the Metropolis Monte Carlo algorithm |
Type |
A1 Journal article |
Year |
2009 |
Publication |
CrystEngComm |
Abbreviated Journal |
Crystengcomm |
Volume |
11 |
Issue |
8 |
Pages |
1597-1608 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, a new implementation of the Metropolis Monte Carlo (MMC) algorithm is presented. When combining the MMC model with a molecular dynamics (MD) code, crystal growth by plasma-enhanced chemical vapor deposition can be simulated. As the MD part simulates impacts of growth species onto the surface on a time scale of picoseconds, the MMC algorithm simulates the slower adatom surface processes. The implementation includes a criterion for the selection of atoms that are allowed to be displaced during the simulation, and a criterion of after how many MMC cycles the simulation is stopped. We performed combined MD-MMC simulations for hydrocarbon species that are important for the growth of ultrananocrystalline diamond (UNCD) films at partially hydrogenated diamond surfaces, since this implementation is part of a study of the growth mechanisms of (ultra)nanocrystalline diamond films. Exemplary for adatom arrangements during the growth of UNCD, the adatom surface behavior of C and C2H2 at diamond (111)1 × 1, C and C4H2 at diamond (111)1 × 1 and C3 at diamond (100)2 × 1 has been investigated. For all cases, the diamond crystal structure is pursued under the influence of MMC simulation. Additional longer time-scale MD simulations put forward very similar structures, verifying the MMC algorithm. Nevertheless, the MMC simulation time is typically one order of magnitude shorter than the MD simulation time. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000268184300021 |
Publication Date |
2009-04-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1466-8033; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.474 |
Times cited |
15 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.474; 2009 IF: 4.183 |
Call Number |
UA @ lucian @ c:irua:77374 |
Serial |
2106 |
Permanent link to this record |
|
|
|
Author |
Mandal, T.K.; Croft, M.; Hadermann, J.; Van Tendeloo, G.; Stephens, P.W.; Greenblatt, M. |
Title |
La2MnVO6 double perovskite: a structural, magnetic and X-ray absorption investigation |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
Volume |
19 |
Issue |
25 |
Pages |
4382-4390 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The synthesis, electron diffraction (ED), synchrotron X-ray and neutron structure, X-ray absorption spectroscopy (XAS) and magnetic property studies of La2MnVO6 double perovskite are described. Analysis of the synchrotron powder X-ray diffraction data for La2MnVO6 indicates a disordered arrangement of Mn and V at the B-site of the perovskite structure. Absence of super-lattice reflections in the ED patterns for La2MnVO6 supports the disordered cation arrangement. Room temperature time-of-flight (TOF) neutron powder diffraction (NPD) data show no evidence of cation ordering, in corroboration with the ED and synchrotron studies (orthorhombic Pnma, a = 5.6097(3), b = 7.8837(5) and c = 5.5668(3) ; 295 K, NPD). A comparison of XAS analyses of La2TVO6 with T = Ni and Co shows T2+ formal oxidation state while the T = Mn material evidences a Mn3+ admixture into a dominantly Mn2+ ground state. V-K edge measurements manifest a mirror image behavior with a V4+ state for T = Ni and Co with a V3+ admixture arising in the T = Mn material. The magnetic susceptibility data for La2MnVO6 show ferromagnetic correlations; the observed effective moment, µeff (5.72 µB) is much smaller than the calculated moment (6.16 µB) based on the spin-only formula for Mn2+ (d5, HS) /V4+ (d1), supportive of the partly oxidized Mn and reduced V scenario (Mn3+/V3+). |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000266989800015 |
Publication Date |
2009-04-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
10 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:77367 |
Serial |
3540 |
Permanent link to this record |
|
|
|
Author |
Müller, K.; Schowalter, M.; Jansen, J.; Tsuda, K.; Titantah, J.; Lamoen, D.; Rosenauer, A. |
Title |
Refinement of the 200 structure factor for GaAs using parallel and convergent beam electron nanodiffraction data |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
7 |
Pages |
802-814 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present a new method to measure structure factors from electron spot diffraction patterns recorded under almost parallel illumination in transmission electron microscopes. Bloch wave refinement routines have been developed to refine the crystal thickness, its orientation and structure factors by comparison of experimentally recorded and calculated intensities. Our method requires a modicum of computational effort, making it suitable for contemporary personal computers. Frozen lattice and Bloch wave simulations of GaAs diffraction patterns are used to derive optimised experimental conditions. Systematic errors are estimated from the application of the method to simulated diffraction patterns and rules for the recognition of physically reasonable initial refinement conditions are derived. The method is applied to the measurement of the 200 structure factor for GaAs. We found that the influence of inelastically scattered electrons is negligible. Additionally, we measured the 200 structure factor from zero loss filtered two-dimensional convergent beam electron diffraction patterns. The precision of both methods is found to be comparable and the results agree well with each other. A deviation of more than 20% from isolated atom scattering data is observed, whereas close agreement is found with structure factors obtained from density functional theory [A. Rosenauer, M. Schowalter, F. Glas, D. Lamoen, Phys. Rev. B 72 (2005), 085326-1], which account for the redistribution of electrons due to chemical bonding via modified atomic scattering amplitudes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000266787900005 |
Publication Date |
2009-03-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
|
Notes |
Fwo; G.0425.05; Esteem; Ant 200611271505 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77361 |
Serial |
2856 |
Permanent link to this record |
|
|
|
Author |
Schattschneider, P.; Verbeeck, J.; Hamon, A.L. |
Title |
Real space maps of atomic transitions |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
7 |
Pages |
781-787 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000266787900002 |
Publication Date |
2009-03-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
10 |
Open Access |
|
Notes |
J.V. acknowledges the FWO-Vlaanderen for support (contract no. G.0147.06) and the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77360UA @ admin @ c:irua:77360 |
Serial |
2829 |
Permanent link to this record |
|
|
|
Author |
Yang, X.-Y.; Li, Y.; Van Tendeloo, G.; Xiao, F.-S.; Su, B.-L. |
Title |
One-pot synthesis of catalytically stable and active nanoreactors: encapsulation of size-controlled nanoparticles within a hierarchically macroporous core@ordered mesoporous shell system |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
21 |
Issue |
13 |
Pages |
1368-1372 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Size-controlled, catalytically active nanoparticles are successfully encapsulated in a one-pot synthesis to form novel hierarchical macroporous core@mesoporous shell structures, where macroporous cores are connected by uniform and ordered mesoporous channels. Most importantly, the encapsulated nanoparticles can be used as nanoreactors, with high activities and excellent long-term recycling stability. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000265432700011 |
Publication Date |
2009-01-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648;1521-4095; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
61 |
Open Access |
|
Notes |
Iap |
Approved |
Most recent IF: 19.791; 2009 IF: NA |
Call Number |
UA @ lucian @ c:irua:77316 |
Serial |
2466 |
Permanent link to this record |
|
|
|
Author |
Bittencourt, C.; van Lier, G.; Ke, X.; Suarez-Martinez, I.; Felten, A.; Ghijsen, J.; Van Tendeloo, G.; Ewels, C.O. |
Title |
Spectroscopy and defect identification for fluorinated carbon nanotubes |
Type |
A1 Journal article |
Year |
2009 |
Publication |
ChemPhysChem : a European journal of chemical physics and physical chemistry |
Abbreviated Journal |
Chemphyschem |
Volume |
10 |
Issue |
6 |
Pages |
920-925 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Multi-wall carbon nanotubes (MWCNTs) were exposed to a CF4 radio-frequency (rf) plasma. High-resolution photoelectron spectroscopy shows that the treatment effectively grafts fluorine atoms onto the MWCNTs, altering the valence electronic states. Fluorine surface concentration can be tuned by varying the exposure time. Evaporation of gold onto MWCNTs is used to mark active site formation. High-resolution transmission electron microscopy coupled with density functional theory (DFT) modelling is used to characterise the surface defects formed, indicating that the plasma treatment does not etch the tube surface. We suggest that this combination of theory and microscopy of thermally evaporated gold atoms onto the CNT surface may be a powerful approach to characterise both surface defect density as well as defect type. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000265469200011 |
Publication Date |
2009-03-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1439-4235;1439-7641; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.075 |
Times cited |
14 |
Open Access |
|
Notes |
Iuap; Fwo |
Approved |
Most recent IF: 3.075; 2009 IF: 3.453 |
Call Number |
UA @ lucian @ c:irua:77315 |
Serial |
3073 |
Permanent link to this record |
|
|
|
Author |
Idrissi, H.; Ryelandt, L.; Veron, M.; Schryvers, D.; Jacques, P.J. |
Title |
Is there a relationship between the stacking fault character and the activated mode of plasticity of FeMn-based austenitic steels? |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
Volume |
60 |
Issue |
11 |
Pages |
941-944 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
By changing the testing temperature, an austenitic FeMnAlSi alloy presents either å-martensite transformation or mechanical twinning during straining. In order to understand the nucleation and growth mechanisms involved in both phenomena, defects and particularly stacking faults, were characterized by transmission electron microscopy. It is observed that the character of the stacking faults also changes (from extrinsic to intrinsic) together with the temperature and the activated mode of plasticity. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000265359900005 |
Publication Date |
2009-02-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.747 |
Times cited |
84 |
Open Access |
|
Notes |
Iap |
Approved |
Most recent IF: 3.747; 2009 IF: 2.949 |
Call Number |
UA @ lucian @ c:irua:77276 |
Serial |
1751 |
Permanent link to this record |
|
|
|
Author |
Verbeeck, J.; Sc hattschneider, P.; Rosenauer, A. |
Title |
Image simulation of high resolution energy filtered TEM images |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
4 |
Pages |
350-360 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000265345400009 |
Publication Date |
2009-01-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
36 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77272UA @ admin @ c:irua:77272 |
Serial |
1552 |
Permanent link to this record |
|
|
|
Author |
van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. |
Title |
Tomographic spectroscopic imaging; an experimental proof of concept |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
109 |
Issue |
4 |
Pages |
296-303 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000265345400003 |
Publication Date |
2008-12-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
Call Number |
UA @ lucian @ c:irua:77271 |
Serial |
3671 |
Permanent link to this record |
|
|
|
Author |
Suarez-Martinez, I.; Bittencourt, C.; Ke, X.; Felten, A.; Pireaux, J.J.; Ghijsen, J.; Drube, W.; Van Tendeloo, G.; Ewels, C.P. |
Title |
Probing the interaction between gold nanoparticles and oxygen functionalized carbon nanotubes |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
47 |
Issue |
6 |
Pages |
1549-1554 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The interaction between evaporated gold and pristine or oxygen plasma treated multi-walled carbon nanotubes (MWCNTs) is investigated. Experimental and theoretical results indicate that gold nucleation occurs at defect sites, whether initially present or introduced by oxygen plasma treatment. Uniform gold cluster dispersion is observed on plasma treated carbon nanotubes (CNTs) and associated with the presence of uniformly dispersed oxidized vacancy centres on the CNT surface. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000265518700018 |
Publication Date |
2009-02-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
38 |
Open Access |
|
Notes |
Pai |
Approved |
Most recent IF: 6.337; 2009 IF: 4.504 |
Call Number |
UA @ lucian @ c:irua:77267 |
Serial |
2717 |
Permanent link to this record |
|
|
|
Author |
Verberck, B.; Vliegenthart, G.A.; Gompper, G. |
Title |
Orientational ordering in solid C60 fullerene-cubane |
Type |
A1 Journal article |
Year |
2009 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
130 |
Issue |
15 |
Pages |
154510,1-154510,14 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the structure and phase behavior of fullerene-cubane C60·C8H8 by Monte Carlo simulation. Using a simple potential model capturing the icosahedral and cubic symmetries of its molecular constituents, we reproduce the experimentally observed phase transition from a cubic to an orthorhombic crystal lattice and the accompanying rotational freezing of the C60 molecules. We elaborate a scheme to identify the low-temperature orientations of individual molecules and to detect a pattern of orientational ordering similar to the arrangement of C60 molecules in solid C60. Our configuration of orientations supports a doubled periodicity along one of the crystal axes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000265486300036 |
Publication Date |
2009-04-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.965 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.965; 2009 IF: 3.093 |
Call Number |
UA @ lucian @ c:irua:77258 |
Serial |
2519 |
Permanent link to this record |
|
|
|
Author |
Nguyen, H.L.; Braun, M.; Szaloki, I.; Baeyens, W.; Van Grieken, R.; Leermakers, M. |
Title |
Tracing the metal pollution history of the Tisza River through the analysis of a sediment depth profile |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Water, air and soil pollution |
Abbreviated Journal |
|
Volume |
200 |
Issue |
|
Pages |
119-132 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The vertical profiles of 20 major and trace metals were investigated along a 180-cm-long sediment core, which was sampled at Kiss-Janosne-Holt Tisza, an oxbow lake located in the upper part of the Tisza River in Hungary. The vertical profiles showed sharp peaks at different depths, reflecting historical pollution events and unusual changes of river water characteristics. Five different groups of metals, containing metals which were strongly correlated and showing a similar behaviour, could be distinguished by factor analysis. Six areas, with variable degrees and types of contamination, were classified in the sediment core with cluster analysis. The most polluted sections were found in the upper 50-cm part (significantly contaminated by Cu, Zn, Pb, Cd and Hg) and the deeper 100120-cm part (characterised by high concentrations of metals associated with mining activities, such as Fe and Mn, as well as Cu, Zn and Pb). In recent years, important pollution events, such as the one which took place in March of 2000, were the reason for pollution of the upper sediment layers, whereas mining activities during the last century were responsible for the pollution of the deeper core sections. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000266487700012 |
Publication Date |
2008-10-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0049-6979; 1573-2932 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:77257 |
Serial |
8695 |
Permanent link to this record |
|
|
|
Author |
Damla, N.; Čevik, U.; Kobya, A.I.; Celik, A.; Van Grieken, R.; Kobya, Y. |
Title |
Characterization of gas concrete materials used in buildings of Turkey |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
Volume |
168 |
Issue |
2/3 |
Pages |
681-687 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The activity concentration of 226Ra, 232Th and 40K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg−1, equivalent to a gamma-dose of 1.5 mSv y−1. Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000268200700014 |
Publication Date |
2009-02-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3894 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:77256 |
Serial |
7621 |
Permanent link to this record |
|
|
|
Author |
Bencs, L.; Krata, A.; Horemans, B.; Buczyńska, A.J.; Dirtu, A.C.; Godoi, A.F.L.; Godoi, R.H.M.; Potgieter-Vermaak, S.; Van Grieken, R. |
Title |
Atmospheric nitrogen fluxes at the Belgian coast: 2004-2006 |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Atmospheric environment : an international journal |
Abbreviated Journal |
|
Volume |
43 |
Issue |
24 |
Pages |
3786-3798 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Daily and seasonal variations in dry and wet atmospheric nitrogen fluxes have been studied during four campaigns between 2004 and 2006 at a coastal site of the Southern North Sea at De Haan (Belgium) located at coordinates of 51.1723° N and 3.0369° E. Concentrations of inorganic N-compounds were determined in the gaseous phase, size-segregated aerosol (coarse, medium, and fine), and rainwater samples. Dissolved organic nitrogen (DON) was quantified in rainwater. The daily variations in N-fluxes of compounds were evaluated with air-mass backward trajectories, classified into the main air-masses arriving at the sampling site (i.e., continental, North Sea, and Atlantic/UK/Channel). The three, non-episodic campaigns showed broadly consistent fluxes, but during the late summer campaign exceptionally high episodic N-deposition was observed. The average dry and wet fluxes for non-episodic campaigns amounted to 2.6 and 4.0 mg N m−2 d−1, respectively, whereas during the episodic late summer period these fluxes were as high as 5.2 and 6.2 mg N m−2 d−1, respectively. Non-episodic seasons/campaigns experienced average aerosol fluxes of 0.91.4 mg N m−2 d−1. Generally, the contribution of aerosol NH4+ was more significant in the medium and fine particulate fractions than that of aerosol NO3−, whereas the latter contributed more in the coarse fraction, especially in continental air-masses. During the dry mid-summer campaign, the DON contributed considerably (15%) to the total N-budget. Exceptionally high episodic aerosol-N inputs have been observed for the late summer campaign, with especially high deposition rates of 3.6 and 2.9 mg N m−2 d−1 for Atlantic/UK/Channel and North Sea-continental (mixed) air-masses, respectively. During this pollution episode, the flux of NH4+ was dominating in each aerosol fraction/air-mass, except for coarse continental aerosols. High deposition of gaseous-N was also observed in this campaign with an average total N-flux of 22.5-times higher than in other campaigns. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000268609000015 |
Publication Date |
2009-04-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1352-2310 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:77255 |
Serial |
7527 |
Permanent link to this record |
|
|
|
Author |
Beyers, E.; Biermans, E.; Ribbens, S.; de Witte, K.; Mertens, M.; Meynen, V.; Bals, S.; Van Tendeloo, G.; Vansant, E.F.; Cool, P. |
Title |
Combined TiO2/SiO2 mesoporous photocatalysts with location and phase controllable TiO2 nanoparticles |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Applied catalysis : B : environmental |
Abbreviated Journal |
Appl Catal B-Environ |
Volume |
88 |
Issue |
3/4 |
Pages |
515-524 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
Abstract |
Combined TiO2/SiO2 mesoporous materials were prepared by deposition of TiO2 nanoparticles synthesised via the acid-catalysed solgel method. In the first synthesis step a titania solution is prepared, by dissolving titaniumtetraisopropoxide in nitric acid. The influences of the initial titaniumtetraisopropoxide concentration and the temperature of dissolving on the final structural properties were investigated. In the second step of the synthesis, the titania nanoparticles were deposited on a silica support. Here, the influence of the temperature during deposition was studied. The depositions were carried out on two different mesoporous silica supports, SBA-15 and MCF, leading to substantial differences in the catalytic and structural properties. The samples were analysed with N2-sorption, X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) to obtain structural information, determining the amount of titania, the crystal phase and the location of the titania particles on the mesoporous material (inside or outside the mesoporous channels). The structural differences of the support strongly determine the location of the nanoparticles and the subsequent photocatalytic activity towards the degradation of rhodamine 6G in aqueous solution under UV irradiation. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000266513400032 |
Publication Date |
2008-10-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-3373; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.446 |
Times cited |
69 |
Open Access |
|
Notes |
Goa-Bof; Fwo |
Approved |
Most recent IF: 9.446; 2009 IF: 5.252 |
Call Number |
UA @ lucian @ c:irua:77150 |
Serial |
403 |
Permanent link to this record |
|
|
|
Author |
Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. |
Title |
Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
Volume |
19 |
Issue |
18 |
Pages |
2660-2670 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000265740600002 |
Publication Date |
2009-02-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
9 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:77065 |
Serial |
68 |
Permanent link to this record |