| Records |
| Author |
Wu, Z.; Peeters, F.M.; Chang, K. |
| Title |
Electron tunneling through double magnetic barriers on the surface of a topological insulator |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
115211-115211,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study electron tunneling through a planar magnetic and electric barrier on the surface of a three-dimensional topological insulator. For the double barrier structures, we find (i) a directional-dependent tunneling which is sensitive to the magnetic field configuration and the electric gate voltage, (ii) a spin rotation controlled by the magnetic field and the gate voltage, (iii) many Fabry-Pérot resonances in the transmission determined by the distance between the two barriers, and (iv) the electrostatic potential can enhance the difference in the transmission between the two magnetization configurations, and consequently lead to a giant magnetoresistance. Points (i), (iii), and (iv) are alike with that in graphene stemming from the same linear-dispersion relations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos  |
000282125700002 |
Publication Date |
2010-09-27 |
| 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 |
65 |
Open Access |
|
| Notes |
; This work was supported by the NSF of China, the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85420 |
Serial |
990 |
| Permanent link to this record |
| |
|
| |
| Author |
Falkenberg, G.; Fleissner, G.E.; Fleissner, G.U.E.; Schuchardt, K.; Kühbacher, M.; Chalmin, E.; Janssens, K. |
| Title |
High resolution micro-XRF maps of iron oxides inside sensory dendrites of putative avian magnetoreceptors |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
| Volume |
186 |
Issue |
1 |
Pages |
012084-3 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Iron mineral containing sensory dendrites in the inner lining of the upper beak of homing pigeons [1] and various bird species [2] are the first candidate structures for an avian magnetic field receptor. A new concept of magnetoreception [3, 4] is based on detailed ultra-structural optical and electron microscopy analyses in combination with synchrotron radiation microscopic X-ray fluorescence analysis (micro-XRF) and microscopic X-ray absorption near edge structures (micro-XANES). Several behavioral experiments [5, 6] and first mathematical simulations [6] affirm our avian magnetoreceptor model. The iron minerals inside the dendrites are housed in three different subcellular compartments (bullets, platelets, vesicles), which could be clearly resolved and identified by electron microscopy on ultrathin sections [1, 3]. Micro-XRF and micro-XANES data obtained at HASYLAB beamline L added information about the elemental distribution and Fe speciation [3], but are averaged over the complete dendrite due to limited spatial resolution. Here we present recently performed micro-XRF maps with sub-micrometer resolution (ESRF ID21), which reveal for the first time subcellular structural information from almost bulk-like dendrite sample material. Due to the thickness of 30 μm the microarchitecture of the dendrites can be considered as undisturbed and artefacts introduced by sectioning might be widely reduced. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282023900084 |
Publication Date |
2009-09-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1742-6588; 1742-6596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
2 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:111317 |
Serial |
5642 |
| 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 |
Harlay, J.; Borges, A.V.; van der Zee, C.; Delille, B.; Godoi, R.H.M.; Schiettecatte, L.-S.; Roevros, N.; Aerts, K.; Lapernat, P.-E.; Rebreanu, L.; Groom, S.; Daro, M.-H.; Van Grieken, R.; Chou, L. |
| Title |
Biogeochemical study of a coccolithophore bloom in the northern Bay of Biscay (NE Atlantic Ocean) in June 2004 |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Progress in oceanography |
Abbreviated Journal |
|
| Volume |
86 |
Issue |
3/4 |
Pages |
317-336 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The present paper synthesizes data obtained during a multidisciplinary cruise carried out in June 2004 at the continental margin of the northern Bay of Biscay. The data-set allows to describe the different stages of a coccolithophore bloom dominated by Emiliania huxleyi. The cruise was carried out after the main spring phytoplankton bloom that started in mid-April and peaked in mid-May. Consequently, low phosphate (PO4 < 0.2 μM) and silicate (DSi < 2.0 μM) concentrations, low partial pressure of carbon dioxide (pCO2) and high calcite saturation degree in surface waters combined with thermal stratification, probably favoured the blooming of coccolithophores. During the period of the year our cruise was carried out, internal tides induce enhanced vertical mixing at the continental shelf break leading to the injection of inorganic nutrients to surface waters that probably trigger the bloom. The bloom developed as the water-column stratified and as the water mass was advected over the continental shelf, following the general residual circulation in the area. The most developed phase of the bloom was sampled in a remote sensed high reflectance (HR) patch over the continental shelf that was characterized by low chlorophyll-a (Chl-a) concentration in surface waters (<1.0 μg L−1), high particulate inorganic carbon (PIC) concentration (not, vert, similar8 μmol L−1) and coccolithophore abundance up to 57 × 106 cells L−1. Transparent exopolymer particles (TEP) concentrations ranged between 15 and 75 μg C L−1 and carbon content of TEP represented up to 26% of the particulate organic carbon (POC; maximum concentration of 15.5 μmol L−1 in the upper 40 m). Integrated primary production (PP) ranged between 210 and 680 mg C m−2 d−1 and integrated calcification (CAL) ranged between 14 and 140 mg C m−2 d−1, within the range of PP and CAL values previously reported during coccolithophore blooms in open and shelf waters of the North Atlantic Ocean. Bacterial protein production (BPP) measurements in surface waters (0.30.7 μg C L−1 h−1) were much higher than those reported during early phases of coccolithophore blooms in natural conditions, but similar to those during peak and declining coocolithophorid blooms reported in mesocosms. Total alkalinity anomalies with respect to conservative mixing (ΔTA) down to −49 μmol kg−1 are consistent with the occurrence of biogenic precipitation of calcite, while pCO2 remained 15107 μatm lower than atmospheric equilibrium (372 μatm). The correlation between ΔTA and pCO2 suggested that pCO2 increased in part due to calcification, but this increase was insufficient to overcome the background under-saturation of CO2. This is related to the biogeochemical history of the water masses due to net carbon fixation by the successive phytoplankton blooms in the area prior to the cruise, hence, the investigated area remained a sink for atmospheric CO2 despite calcification. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281937800001 |
Publication Date |
2010-04-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0079-6611 |
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:84236 |
Serial |
7560 |
| Permanent link to this record |
| |
|
| |
| Author |
Ludu, A.; Van Deun, J.; Milošević, M.V.; Cuyt, A.; Peeters, F.M. |
| Title |
Analytic treatment of vortex states in cylindrical superconductors in applied axial magnetic field |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of mathematical physics |
Abbreviated Journal |
J Math Phys |
| Volume |
51 |
Issue |
8 |
Pages |
082903,1-082903,29 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We solve the linear GinzburgLandau (GL) equation in the presence of a uniform magnetic field with cylindrical symmetry and we find analytic expressions for the eigenfunctions in terms of the confluent hypergeometric functions. The discrete spectrum results from an implicit equation associated to the boundary conditions and it is resolved in analytic form using the continued fractions formalism. We study the dependence of the spectrum and the eigenfunctions on the sample size and the surface conditions for solid and hollow cylindrical superconductors. Finally, the solutions of the nonlinear GL formalism are constructed as expansions in the linear GL eigenfunction basis and selected by minimization of the free energy. We present examples of vortex states and their energies for different samples in enhancing/suppressing superconductivity surroundings. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000281905000026 |
Publication Date |
2010-08-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2488; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.077 |
Times cited |
10 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.077; 2010 IF: 1.291 |
| Call Number |
UA @ lucian @ c:irua:84880 |
Serial |
106 |
| Permanent link to this record |
| |
|
| |
| Author |
Khaydarov, R.T.; Beisinbaeva, H.B.; Sabitov, M.M.; Kalal, M.; Berdiyorov, G.R. |
| Title |
Conditions defining the mechanisms of the formation of light gas ions in multicomponent laser-produced plasmas |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Nuclear fusion |
Abbreviated Journal |
Nucl Fusion |
| Volume |
50 |
Issue |
10 |
Pages |
105007,1-105007,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the mass-spectrometric method we study the charge, energy and spatial characteristics of ions in multicomponent plasma, generated under the action of Nd : YAG laser radiation on the surface of solid targets. We focus on the effect of the entry form of light gas atoms on the parameters of ions in such laser-produced plasmas. We found that the presence of light gas atoms considerably affects the parameters (e.g. the intensity and the charge multiplicity) of the heavier ions. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Vienna |
Editor |
|
| Language |
|
Wos |
000281859300008 |
Publication Date |
2010-08-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0029-5515;1741-4326; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.307 |
Times cited |
1 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.307; 2010 IF: 3.303 |
| Call Number |
UA @ lucian @ c:irua:84876 |
Serial |
476 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Heuvel, W.; Tikhomirov, V.K.; Kirilenko, D.; Schildermans, N.; Chibotaru, L.F.; Vanacken, J.; Gredin, P.; Mortier, M.; Van Tendeloo, G.; Moshchalkov, V.V. |
| Title |
Ultralow blocking temperature and breakdown of the giant spin model in Er3+-doped nanoparticles |
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 |
094421-094421,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The magnetization of luminescent Er3+-doped PbF2 nanoparticles (formula Er0.3Pb0.7F2.3) has been studied. Despite the high concentration of the doping Er3+ ions and relatively large size (8 nm) of these nanoparticles we have found no deviation between field-cooled and zero-field-cooled magnetization curves down to T=0.35 K, which points out an ultralow blocking temperature for the reversal of magnetization. We also have found strongly deviating magnetization curves M(H/T) for different temperatures T. These results altogether show that the investigated nanoparticles are not superparamagnetic, but rather each Er3+ ion in these nanoparticles is found in a paramagnetic state down to very low temperatures, which implies the breakdown of the Néel-Brown giant spin model in the case of these nanoparticles. Calculations of magnetization within a paramagnetic model of noninteracting Er3+ ions completely support this conclusion. Due to the ultralow blocking temperature, these nanoparticles have a potential for magnetic field-induced nanoscale refrigeration with an option of their optical localization and temperature control. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281773300005 |
Publication Date |
2010-09-13 |
| 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 |
11 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85423 |
Serial |
3796 |
| Permanent link to this record |
| |
|
| |
| Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Fabry-Pérot resonances in graphene microstructures: influence of a magnetic field |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
115417-115417,12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Fabry-Pérot resonances in the transmission through single and double, graphene-based barriers (of height V) and wells are investigated and their dependence on an applied perpendicular magnetic field. For rectangular barriers the conductance decreases with increasing magnetic field while the resonances weaken (become more pronounced) with increasing magnetic field for EF<V (EF>V). The position of the resonances exhibit a linear shift with magnetic field which move to lower (higher) energy for EF<V (EF>V). Compared to semielliptic- or Gaussian-shaped barriers they show a smaller number of resonances in the absence of a magnetic field and an overall lower conductance but the resonant structure is more pronounced. The conductance of asymmetric double barriers show two major regions of resonances while the symmetric ones show one, that of three asymmetric barriers three, and so on. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281723100007 |
Publication Date |
2010-09-10 |
| 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 |
74 |
Open Access |
|
| Notes |
; This work was supported by 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:84871 |
Serial |
1167 |
| Permanent link to this record |
| |
|
| |
| Author |
Meilikhov, M.; Yusenko, K.; Esken, D.; Turner, S.; Van Tendeloo, G.; Fischer, R.A. |
| Title |
Metals@MOFs – loading MOFs with metal nanoparticles for hybrid functions |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
| Volume |
2010 |
Issue |
24 |
Pages |
3701-3714 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Metalorganic frameworks (MOFs) as well as porous coordination polymers (PCPs) are porous, organicinorganic hybrid solids with zeolite-like structures and properties. Due to their extraordinarily high surface area and well defined pore structure MOFs can be used for the stabilization of metal nanoparticles with adjustable size. The embedded metal nanoparticles are still accessible for other reagents due to the high porosity of the MOF systems. This fact makes metal@MOF systems especially interesting for heterogeneous catalysis, gas storage and chemical sensing. This review compiles the cases of metal nanoparticles supported by or embedded into MOFs reported so far and the main aspects and problems associated with these novel nanocomposite systems. The determination of the dispersion and the location of the particles at the MOF support, the control of the loading degree and its effect on the catalytic activity of the system are discussed as well as the partial degradation of the MOF structure upon particle formation. Examples of the introduction of stabilizing groups into the MOF network that direct the loading and can influence the size and shape of the embedded particles are still rare and point into the possible direction of future investigations. Finally, the formation of bimetallic nanoparticles, which are stabilized and supported by a MOF network, will also be reviewed. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000281684300001 |
Publication Date |
2010-07-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1434-1948; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.444 |
Times cited |
366 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 2.444; 2010 IF: 2.910 |
| Call Number |
UA @ lucian @ c:irua:85495 |
Serial |
2014 |
| Permanent link to this record |
| |
|
| |
| Author |
Barbier, M.; Vasilopoulos, P.; Peeters, F.M.; Pereira, J.M. |
| Title |
Band structure, density of states, and transmission in graphene bilayer superlattices |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
AIP conference proceedings |
Abbreviated Journal |
|
| Volume |
1199 |
Issue |
|
Pages |
547-548 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The energy spectrum and density of states of graphene bilayer superlattices (SLs) are evaluated. We take into account doping and/or gating of the layers as well as tunnel coupling between them. In addition, we evaluate the transmission through such SLs and through single or double barriers. The transmission exhibits a strong dependence on the direction of the incident wave vector. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York |
Editor |
|
| Language |
|
Wos |
000281590800258 |
Publication Date |
2010-01-15 |
| 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:84893 |
Serial |
217 |
| Permanent link to this record |
| |
|
| |
| Author |
Masir, M.R.; Vasilopoulos, P.; Matulis, A.; Peeters, F.M. |
| Title |
Angular confinement and direction-dependent transmission in graphene nanostructures with magnetic barriers |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
AIP conference proceedings |
Abbreviated Journal |
|
| Volume |
1199 |
Issue |
|
Pages |
363-364 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We evaluate the transmission through magnetic barriers in graphene-based nanostructures. Several particular cases are considered: a magnetic step, single and double barriers, delta -function barriers as well as barrier structures with inhomogeneous magnetic field profiles but with average magnetic field equal to zero. The transmission exhibits a strong dependence on the direction of the incident wave vector. In general the resonant structure of the transmission is significantly more pronounced for (Dirac) electrons with linear spectrum compared to that for electrons with a parabolic one. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York |
Editor |
|
| Language |
|
Wos |
000281590800171 |
Publication Date |
2010-01-15 |
| 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:84892 |
Serial |
115 |
| Permanent link to this record |
| |
|
| |
| Author |
Peelaers, H.; Partoens, B.; Peeters, F.M. |
| Title |
Phonon band structures of Si nanowires |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
AIP conference proceedings |
Abbreviated Journal |
|
| Volume |
1199 |
Issue |
|
Pages |
323-324 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the [110] direction. Using these phonon dispersion relations we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York |
Editor |
|
| Language |
|
Wos |
000281590800153 |
Publication Date |
2010-01-15 |
| 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:84891 |
Serial |
2602 |
| Permanent link to this record |
| |
|
| |
| Author |
Afanasov, I.M.; Van Tendeloo, G.; Mateev, A.T. |
| Title |
Production and structure of exfoliated graphite/coke composites modified by ZrO2 nanoparticles |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
New carbon materials |
Abbreviated Journal |
|
| Volume |
25 |
Issue |
4 |
Pages |
255-260 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Exfoliated graphite/coke composites modified by ZrO2 nanoparticles were produced using two different techniques and characterized by means of X-ray diffraction, scanning and transmission electron microscopy. In the first, low-density exfoliated graphite/coke blocks were dipped repeatedly and alternately in ZrO(NO3)2 and NH4OH solutions and subsequently heat treated at 1200°C in nitrogen to deposit thin layers of ZrO2 nanoparticles on the free surfaces of the carbon matrix. In the second, a mixture of expandable graphite, phenol-formaldehyde resin powder, and ZrOC2O4-modified fibrous cellulose in a sealed container was submitted to thermal shock at 900 °C followed by heat treatment at 1 200 °C in nitrogen to obtain the modified composites. The ZrO2 nanoparticles formed in the second technique were incorporated into the composites in three length scales: 6-30 nm-isolated nanoparticles and small blobs, 200-1000 nm-lengthy dendrite-like structures, and thin layer adhering to the surface of the 1-40 μm long cellulose carbon fibers. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281534800003 |
Publication Date |
2010-09-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1872-5805; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
Iap-Vi |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:84438 |
Serial |
2721 |
| Permanent link to this record |
| |
|
| |
| Author |
Xu, W.; Dong, H.M.; Li, L.L.; Yao, J.Q.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Optoelectronic properties of graphene in the presence of optical phonon scattering |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
12 |
Pages |
125304-125304,9 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study in detail the optoelectronic properties of graphene. Considering the electron interactions with photons and phonons, we employ the mass- and energy-balance equations to self-consistently evaluate the photoinduced carrier densities, the optical conductance, and the transmission coefficient in the presence of a linearly polarized radiation field. We demonstrate that the photoinduced carrier densities increase around the electron-photon-phonon resonant transition. They depend strongly on the radiation intensity and frequency, temperature, and dark carrier density. For short-wavelength radiation (L<3 μm), we obtain the universal optical conductance σ0=e2/(4ℏ). Importantly, there exists an optical-absorption window in the radiation wavelength range 4100 μm, which is induced by different transition energies required for interband and intraband optical absorption. The position and width of this window depend sensitively on the temperature and the carrier density of the system. These theoretical results are in line with recent experimental findings and indicate that graphene exhibits important features not only in the visible regime but also in the midinfrared bandwidth. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281516500009 |
Publication Date |
2010-09-03 |
| 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 Chinese Academy of Sciences, National Natural Science Foundation of China, 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:84260 |
Serial |
2496 |
| Permanent link to this record |
| |
|
| |
| Author |
Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M. |
| Title |
Spin-orbit interaction controlled properties of two-dimensional superlattices |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
115302-115302,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The band structure of two-dimensional artificial superlattices in the presence of (Rashba-type) spin-orbit interaction (SOI) is presented. The position and shape of the energy bands in these spintronic crystals depend on the geometry as well as the strength of the SOI, which can be tuned by external gate voltages. For finite mesoscopic arrays, we show that their conductance properties and possible applications can be understood from these spin-dependent band diagrams. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281516300005 |
Publication Date |
2010-09-03 |
| 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 |
6 |
Open Access |
|
| Notes |
; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and No. M045596. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84259 |
Serial |
3092 |
| Permanent link to this record |
| |
|
| |
| Author |
Eckert, M.; Neyts, E.; Bogaerts, A. |
| Title |
Differences between ultrananocrystalline and nanocrystalline diamond growth: theoretical investigation of CxHy species at diamond step edges |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
| Volume |
10 |
Issue |
9 |
Pages |
4123-4134 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The behavior of hydrocarbon species at step edges of diamond terraces is investigated by means of combined molecular dynamics−Metropolis Monte Carlo simulations. The results show that the formation of ballas-like diamond films (like UNCD) and well-faceted diamond films (like NCD) can be related to the gas phase concentrations of CxHy in a new manner: Species that have high concentrations above the growing UNCD films suppress the extension of step edges through defect formation. The species that are present above the growing NCD film, however, enhance the extension of diamond terraces, which is believed to result in well-faceted diamond films. Furthermore, it is shown that, during UNCD growth, CxHy species with x ≥ 2 play an important role, in contrast to the currently adopted CVD diamond growth mechanism. Finally, the probabilities for the extension of the diamond (100) terrace are much higher than those for the diamond (111) terrace, which is in full agreement with the experimental observation that diamond (100) facets are more favored than diamond (111) facets during CVD diamond growth. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281353900042 |
Publication Date |
2010-08-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.055 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.055; 2010 IF: 4.390 |
| Call Number |
UA @ lucian @ c:irua:83696 |
Serial |
694 |
| Permanent link to this record |
| |
|
| |
| Author |
Pogosov, W.V.; Misko, V.R.; Peeters, F.M. |
| Title |
Geometry-induced localization of thermal fluctuations in ultrathin superconducting structures |
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 |
054523-054523,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Thermal fluctuations of the order parameter in an ultrathin triangular-shaped superconducting structure are studied near Tc, in zero applied field. We find that the order parameter is prone to much larger fluctuations in the corners of the structure as compared to its interior. This geometry-induced localization of thermal fluctuations is attributed to the fact that condensate confinement in the corners is characterized by a lower effective dimensionality, which favors stronger fluctuations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281294700006 |
Publication Date |
2010-08-27 |
| 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 |
2 |
Open Access |
|
| Notes |
; This work was supported by the “Odysseus” Program of the Flemish government, FWO-Vl, and the Belgian Science Policy (IAP). W. V. P. acknowledges supports from the RFBR [Project No. 09-02-00248] and the “Dynasty Foundation.” ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84470 |
Serial |
1334 |
| Permanent link to this record |
| |
|
| |
| Author |
Schattschneider, P.; Ennen, I.; Stoger-Pollach, M.; Verbeeck, J.; Mauchamp, V.; Jaouen, M. |
| Title |
Real space maps of magnetic moments on the atomic scale: theory and feasibility |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
110 |
Issue |
8 |
Pages |
1038-1041 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The recently discovered EMCD technique (energy loss magnetic chiral dichroism) can detect atom specific magnetic moments with nanometer resolution, exploiting the spin selectivity of electronic transitions in energy loss spectroscopy. Yet, direct imaging of magnetic moments on the atomic scale is not possible. In this paper we present an extension of EMCD that can overcome this limit. As a model system we chose bcc Fe. We present image simulations of the L3 white line signal, based on the kinetic equation for the density matrix of the 200 kV probe electron. With actual progress in instrumentation (high brightness sources, aberration corrected lenses) this technique should allow direct imaging of spin moments on the atomic scale. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000281216600016 |
Publication Date |
2009-12-07 |
| 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 |
--- |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
| Call Number |
UA @ lucian @ c:irua:84439UA @ admin @ c:irua:84439 |
Serial |
2830 |
| Permanent link to this record |
| |
|
| |
| Author |
Ao, Z.M.; Peeters, F.M. |
| Title |
Electric field activated hydrogen dissociative adsorption to nitrogen-doped graphene |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
114 |
Issue |
34 |
Pages |
14503-14509 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Graphane, hydrogenated graphene, was very recently synthesized and predicted to have great potential applications. In this work, we propose a new promising approach for hydrogenation of graphene based on density functional theory (DFT) calculations through the application of a perpendicular electric field after substitutionally doping by nitrogen atoms. These DFT calculations show that the doping by nitrogen atoms into the graphene layer and applying an electrical field normal to the graphene surface induce dissociative adsorption of hydrogen. The dissociative adsorption energy barrier of an H2 molecule on a pristine graphene layer changes from 2.7 to 2.5 eV on N-doped graphene, and to 0.88 eV on N-doped graphene under an electric field of 0.005 au. When increasing the electric field above 0.01 au, the reaction barrier disappears. Therefore, N doping and applying an electric field have catalytic effects on the hydrogenation of graphene, which can be used for hydrogen storage purposes and nanoelectronic applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000281129100027 |
Publication Date |
2010-08-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
110 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 4.536; 2010 IF: 4.524 |
| Call Number |
UA @ lucian @ c:irua:84588 |
Serial |
882 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Graphene nanoribbons subjected to axial stress |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
8 |
Pages |
085432-085432,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Atomistic simulations are used to study the bending of rectangular graphene nanoribbons subjected to axial stress both for free boundary and supported boundary conditions. The shapes of the deformations of the buckled graphene nanoribbons, for small values of the stress, are sine waves where the number of nodal lines depend on the longitudinal size of the system and the applied boundary condition. The buckling strain for the supported boundary condition is found to be independent of the longitudinal size and estimated to be 0.86%. From a calculation of the free energy at finite temperature we find that the equilibrium projected two-dimensional area of the graphene nanoribbon is less than the area of a flat sheet. At the optimum length the boundary strain for the supported boundary condition is 0.48%. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281065100007 |
Publication Date |
2010-08-20 |
| 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 |
92 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84583 |
Serial |
1373 |
| Permanent link to this record |
| |
|
| |
| Author |
Bekermann, D.; Gasparotto, A.; Barreca, D.; Devi, A.; Fischer, R.A.; Kete, M.; Štangar, U.L.; Lebedev, O.I.; Maccato, C.; Tondello, E.; Van Tendeloo, G. |
| Title |
ZnO nanorod arrays by plasma-enhanced CVD for light-activated functional applications |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
ChemPhysChem : a European journal of chemical physics and physical chemistry |
Abbreviated Journal |
Chemphyschem |
| Volume |
11 |
Issue |
11 |
Pages |
2337-2340 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Switch of the surface properties: Supported ZnO nanorod arrays with tailored roughness and aspect ratios are successfully synthesized by plasma-enhanced chemical vapor deposition. Such nanostructures exhibit significant superhydrophilic and photocatalytic properties tunable as a function of their morphological organization (see picture). This renders them promising building blocks for the fabrication of stimuli-responsive materials. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000281061500008 |
Publication Date |
2010-06-16 |
| 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 |
38 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 3.075; 2010 IF: 3.340 |
| Call Number |
UA @ lucian @ c:irua:84594 |
Serial |
3935 |
| 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 |
Krstajić, P.M.; Peeters, F.M.; Helm, M. |
| Title |
Landau levels and magnetopolaron effect in dilute GaAs:N |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
| Volume |
150 |
Issue |
33/34 |
Pages |
1575-1579 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The magnetic-field dependence of the energy spectrum of GaAs doped with nitrogen impurities is investigated. Our theoretical model is based on the phenomenological band anticrossing model (BAC) which we extended in order to include the magnetic field and electronphonon interaction. Due to the highly localized nature of the nitrogen state, we find that the energy levels are very different from those of pure GaAs. The polaron correction results in a lower cyclotron resonance energy as compared to pure GaAs. The magneto-absorption spectrum exhibits series of asymmetric peaks close to the cyclotron energy ħωc. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000280949900019 |
Publication Date |
2010-06-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
1.554 |
Times cited |
|
Open Access |
|
| Notes |
; This work is supported by the Flemish Science Foundation (FWO-VI), and the Interuniversity Attraction Poles Program (IAP)-Belgian State Science Policy. M.H. is grateful to O. Drachenko and H. Schneider for numerous discussions. ; |
Approved |
Most recent IF: 1.554; 2010 IF: 1.981 |
| Call Number |
UA @ lucian @ c:irua:84580 |
Serial |
1771 |
| Permanent link to this record |
| |
|
| |
| 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 |
Ding, F.; Akopian, N.; Li, B.; Perinetti, U.; Govorov, A.; Peeters, F.M.; Bufon, C.C.; Deneke, C.; Chen, Y.H.; Rastelli, A.; Schmidt, O.G.; Zwiller, V. |
| Title |
Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings |
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 |
8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000280813100005 |
Publication Date |
2010-08-11 |
| 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 |
58 |
Open Access |
|
| Notes |
; We acknowledge L. P. Kouwenhoven and Z. G. Wang for support, L. Wang, V. Fomin, S. Kiravittaya, M. Tadic, Wen-Hao Chang, I. Sellers, A. Avetisyan, and C. Pryor for fruitful discussions and the financial support of NWO (VIDI), the CAS-MPG program, the DFG (FOR730), BMBF (Grant No. 01BM459), NSFC (Grant No. 60625402), and Flemish Science Foundation (FWO-V1). Access to the TEM of B. Rellinghaus is acknowledged. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:83992 |
Serial |
1321 |
| Permanent link to this record |
| |
|
| |
| Author |
Figuerola, A.; van Huis, M.; Zanella, M.; Genovese, A.; Marras, S.; Falqui, A.; Zandbergen, H.W.; Cingolani, R.; Manna, L. |
| Title |
Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
| Volume |
10 |
Issue |
8 |
Pages |
3028-3036 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington |
Editor |
|
| Language |
|
Wos |
000280728900049 |
Publication Date |
2010-07-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1530-6984;1530-6992; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.712 |
Times cited |
112 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 12.712; 2010 IF: 12.219 |
| Call Number |
UA @ lucian @ c:irua:83995 |
Serial |
1069 |
| Permanent link to this record |
| |
|
| |
| Author |
Bezjak, J.; Abakumov, A.M.; Recnik, A.; Krzmanc, M.M.; Jancar, B.; Suvorov, D. |
| Title |
The local structure and composition of Ba4Nb2O9-based oxycarbonates |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| Volume |
183 |
Issue |
8 |
Pages |
1823-1828 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
X-ray powder-diffraction(XRD),high-resolutiontransmissionelectronmicroscopy(HRTEM),electron diffraction(ED),infraredspectroscopy(IR),thermogravimetry(TG)andmassspectroscopy(MS)were performedtoinvestigatethecompositionandthecrystalstructureoftetra-bariumdi-niobate(V) Ba4Nb2O9. TheTG,MSandIRstudiesrevealedthatthecompoundisahydratedoxycarbonate.Assuming that thecarbonatestoichiometricallyreplacesoxygen,thecompositionofthelow-temperature a-modification,obtainedbyslowcoolingfrom1100 1C, correspondstoBa4Nb2O8.8(CO3)0.2 0.1H2O, while thequenchedhigh-temperature g-modificationhastheBa4Nb2O8.42(CO3)0.58 0.38H2O composi- tion. The a-phase hasacompositeincommensuratelymodulatedstructureconsistingoftwomutually interacting[Ba]N and the[(Nb,)O3]N subsystems.Thecompositemodulatedcrystalstructureofthe a-phase canbedescribedwiththelatticeparameters a¼10.2688(1) A˚ , c¼2.82426(8) A˚ , q¼0.66774(2)c* and asuperspacegroup R3m(00g)0s. TheHRTEManalysisdemonstratesthenanoscale twinningofthetrigonaldomainsparalleltothe{100}crystallographicplanes.Thetwinningintroduces a one-dimensionaldisorderintothe[(Nb,)O3]N subsystem,whichresultsinanaverage P62c crystal structureofthe a-phase. Possibleplacesforthecarbonategroupinthestructurearediscussedusinga comparisonwithotherhexagonalperovskite-basedoxycarbonates. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000280620300013 |
Publication Date |
2010-06-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.299 |
Times cited |
10 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.299; 2010 IF: 2.261 |
| Call Number |
UA @ lucian @ c:irua:84046 |
Serial |
1830 |
| Permanent link to this record |
| |
|
| |
| Author |
Terzano, R.; Santoro, A.; Spagnuolo, M.; Vekemans, B.; Medici, L.; Janssens, K.; Göttlicher, J.; Denecke, M.A.; Mangold, S.; Ruggiero, P. |
| Title |
Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Environmental pollution |
Abbreviated Journal |
Environ Pollut |
| Volume |
158 |
Issue |
8 |
Pages |
2702-2709 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg1. Hg chemical forms were identified and quantified by sequential extractions and bulkand micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as m-XRF, m-XRD and m-XANES were necessary to solve bulk Hg speciation, in both soil fractions <2 mm and <2 mm. The main Hg-species found in the soil samples were metacinnabar (b-HgS), cinnabar (a-HgS), corderoite (Hg3S2Cl2), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction <2 mm. No interaction among Hg-species and soil components was observed. All the observed Hgspecies originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000280571500026 |
Publication Date |
2010-06-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0269-7491 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.099 |
Times cited |
30 |
Open Access |
|
| Notes |
; This research was partially financed by the MIUR (COFIN 2005) project “Innovative chemical, physical, and biological methods to characterize and remediate soils polluted by heavy metals (MICROS)”. Synchrotron experiments at HASYLAB were financially supported by the European Community-Research Infrastructure Action under the FP6 “Structuring the European Research Area” Program I(Integrating Activity on Synchrotron and Free Electron Laser Science; project: contract RII3-CT-2004-506008). This research was also performed as part of the “Interuniversity Attraction Poles” (IAP6) Program financed by the Belgian government. We thank Gerald Falkenberg and Karen Rickers-Appel for their scientific and technical support in obtaining the experimental data at Beam line L (HASYLAB, DESY, Hamburg, Germany). ; |
Approved |
Most recent IF: 5.099; 2010 IF: 3.395 |
| Call Number |
UA @ admin @ c:irua:84050 |
Serial |
5835 |
| 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 |
Fang, C.M.; Sluiter, M.H.F.; van Huis, M.; Ande, C.K.; Zandbergen, H.W. |
| Title |
Origin of predominance of cementite among iron carbides in steel at elevated temperature |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
105 |
Issue |
5 |
Pages |
4 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A long-standing challenge in physics is to understand why cementite is the predominant carbide in steel. Here we show that the prevalent formation of cementite can be explained only by considering its stability at elevated temperature. A systematic highly accurate quantum mechanical study was conducted on the stability of binary iron carbides. The calculations show that all the iron carbides are unstable relative to the elemental solids, -Fe and graphite. Apart from a cubic Fe23C6 phase, the energetically most favorable carbides exhibit hexagonal close-packed Fe sublattices. Finite-temperature analysis showed that contributions from lattice vibration and anomalous Curie-Weis magnetic ordering, rather than from the conventional lattice mismatch with the matrix, are the origin of the predominance of cementite during steel fabrication processes. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000280472900008 |
Publication Date |
2010-07-30 |
| 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 |
65 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 8.462; 2010 IF: 7.622 |
| Call Number |
UA @ lucian @ c:irua:84064 |
Serial |
2526 |
| Permanent link to this record |
