toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Baguer, N.; Neyts, E.; van Gils, S.; Bogaerts, A. doi  openurl
  Title Study of atmospheric MOCVD of TiO2 thin films by means of computational fluid dynamics simulations Type A1 Journal article
  Year 2008 Publication Chemical vapor deposition Abbreviated Journal Chem Vapor Depos  
  Volume 14 Issue 11/12 Pages 339-346  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract This paper presents the computational study of the metal-organic (MO) CVD of titanium dioxide (TiO2) films grown using titanium tetraisopropoxide (TTIP) as a precursor and nitrogen as a carrier gas. The TiO2 films are deposited under atmospheric pressure. The effects of the precursor concentration, the substrate temperature, and the hydrolysis reaction on the deposition process are investigated. It is found that hydrolysis of the TTIP decreases the onset temperature of the gas-phase thermal decomposition, and that the deposition rate increases with the precursor concentration and with the decrease of substrate temperature. Concerning the mechanism responsible for the film growth, the model shows that at the lowest precursor concentration, the direct adsorption of the precursor is dominant, while at higher precursor concentrations, the monomer deposition becomes more important.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000262215800003 Publication Date 2008-12-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0948-1907;1521-3862; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.333 Times cited 14 Open Access  
  Notes Approved Most recent IF: 1.333; 2008 IF: 1.483  
  Call Number UA @ lucian @ c:irua:71905 Serial 3325  
Permanent link to this record
 

 
Author Khotkevych, V.V.; Milošević, M.V.; Bending, S.J. doi  openurl
  Title A scanning Hall probe microscope for high resolution magnetic imaging down to 300 mK Type A1 Journal article
  Year 2008 Publication The review of scientific instruments Abbreviated Journal Rev Sci Instrum  
  Volume 79 Issue 12 Pages 123708  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present the design, construction, and performance of a low-temperature scanning Hall probe microscope with submicron lateral resolution and a large scanning range. The detachable microscope head is mounted on the cold flange of a commercial 3He-refrigerator (Oxford Instruments, Heliox VT-50) and operates between room temperature and 300 mK. It is fitted with a three-axis slip-stick nanopositioner that enables precise in situ adjustment of the probe location within a 6×6×7 mm3 space. The local magnetic induction at the sample surface is mapped with an easily changeable microfabricated Hall probe [typically GsAs/AlGaAs or AlGaAs/InGaAs/GaAs Hall sensors with integrated scanning tunnel microscopy (STM) tunneling tips] and can achieve minimum detectable fields 10 mG/Hz1/2. The Hall probe is brought into very close proximity to the sample surface by sensing and controlling tunnel currents at the integrated STM tip. The instrument is capable of simultaneous tunneling and Hall signal acquisition in surface-tracking mode. We illustrate the potential of the system with images of superconducting vortices at the surface of a Nb thin film down to 372 mK, and also of labyrinth magnetic-domain patterns of an yttrium iron garnet film captured at room temperature.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000262224800032 Publication Date 2008-12-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0034-6748; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.515 Times cited 14 Open Access  
  Notes Approved Most recent IF: 1.515; 2008 IF: 1.738  
  Call Number UA @ lucian @ c:irua:75725 Serial 2942  
Permanent link to this record
 

 
Author Pogosov, W.V.; Misko, V.R.; Zhao, H.J.; Peeters, F.M. url  doi
openurl 
  Title Collective vortex phases in periodic plus random pinning potential Type A1 Journal article
  Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B  
  Volume 79 Issue 1 Pages 014504,1-014504,12  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study theoretically the simultaneous effect of regular and random pinning potentials on the vortex lattice structure at filling factor of 1. This structure is determined by a competition between the square symmetry of regular pinning array, by the intervortex interaction favoring a triangular symmetry, and by the randomness trying to depin vortices from their regular positions. Both analytical and molecular-dynamics approaches are used. We construct a phase diagram of the system in the plane of regular and random pinning strengths and determine typical vortex lattice defects appearing in the system due to the disorder. We find that the total disordering of the vortex lattice can occur either in one step or in two steps. For instance, in the limit of weak pinning, a square lattice of pinned vortices is destroyed in two steps. First, elastic chains of depinned vortices appear in the film; but the vortex lattice as a whole remains still pinned by the underlying square array of regular pinning sites. These chains are composed into fractal-like structures. In a second step, domains of totally depinned vortices are generated and the vortex lattice depins from regular array.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000262977900092 Publication Date 2009-01-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes Approved Most recent IF: 3.836; 2009 IF: 3.475  
  Call Number UA @ lucian @ c:irua:75982 Serial 386  
Permanent link to this record
 

 
Author Misko, V.R.; Zhao, H.J.; Peeters, F.M.; Oboznov, V.; Dubonos, S.V.; Grigorieva, I.V. doi  openurl
  Title Formation of vortex shells in mesoscopic superconducting squares Type A1 Journal article
  Year 2009 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech  
  Volume 22 Issue 3 Pages 034001,1-034001,8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study vortex configurations in mesoscopic superconducting squares. Our theoretical approach is based on the analytical solution of the London equation using the Green's function method. The potential energy landscape found is then used in Langevin-type molecular-dynamics simulations to obtain stable vortex configurations. We show that the filling rules for vortices in squares with increasing applied magnetic field can be formulated, although in a different manner than in disks, in terms of the formation of vortex 'shells'. We discuss metastable states and the stability of the vortex configurations found with respect to variations of the material parameters and deformations of the shape of the sample.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000263564500002 Publication Date 2009-01-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048;1361-6668; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.878 Times cited 14 Open Access  
  Notes Approved Most recent IF: 2.878; 2009 IF: 2.694  
  Call Number UA @ lucian @ c:irua:76312 Serial 1267  
Permanent link to this record
 

 
Author Kalina, R.; Szafran, B.; Bednarek, S.; Peeters, F.M. doi  openurl
  Title Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate Type A1 Journal article
  Year 2009 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 102 Issue 6 Pages 066807,1-066807,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000263389500056 Publication Date 2009-02-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 14 Open Access  
  Notes Approved Most recent IF: 8.462; 2009 IF: 7.328  
  Call Number UA @ lucian @ c:irua:76315 Serial 1867  
Permanent link to this record
 

 
Author Shanenko, A.A.; Croitoru, M.D.; Peeters, F.M. url  doi
openurl 
  Title Superconducting nanofilms: Andreev-type states induced by quantum confinement Type A1 Journal article
  Year 2008 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B  
  Volume 78 Issue 5 Pages 054505,1-054505,8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)  
  Abstract Quantum confinement of the transverse electron motion is the major effect governing the superconducting properties of high-quality metallic nanofilms, leading to a nonuniform transverse distribution of the superconducting condensate. In this case the order parameter can exhibit significant local enhancements due to these quantum-size effects and, consequently, quasiparticles have lower energies when they avoid the local enhancements of the pair condensate. Such excitations can be considered as new Andreev-type quasiparticles but now induced by quantum confinement. By numerically solving the Bogoliubovde Gennes equations and using Anderson's approximate solution to these equations, we: (a) formulate a criterion for such new Andreev-type states (NATS) and (b) study their effect on the superconducting characteristics in metallic nanofilms. We also argue that nanofilms made of low-carrier-density materials, e.g., of superconducting semiconductors, can be a more optimal choice for the observations of NATS and other quantum-size superconducting effects.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000259368200109 Publication Date 2008-08-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes Approved Most recent IF: 3.836; 2008 IF: 3.322  
  Call Number UA @ lucian @ c:irua:76526 Serial 3356  
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. pdf  doi
openurl 
  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 (up) 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 Wang, M.; Chang, K.; Wang, L.G.; Dai, N.; Peeters, F.M. doi  openurl
  Title Crystallographic plane tuning of charge and spin transport in semiconductor quantum wires Type A1 Journal article
  Year 2009 Publication Nanotechnology Abbreviated Journal Nanotechnology  
  Volume 20 Issue 36 Pages 365202,1-365202,8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate theoretically the charge and spin transport in quantum wires grown along different crystallographic planes in the presence of the Rashba spinorbit interaction (RSOI) and the Dresselhaus spinorbit interaction (DSOI). We find that changing the crystallographic planes leads to a variation of the anisotropy of the conductance due to a different interplay between the RSOI and DSOI, since the DSOI is induced by bulk inversion asymmetry, which is determined by crystallographic plane. This interplay depends sensitively on the crystallographic planes, and consequently leads to the anisotropic charge and spin transport in quantum wires embedded in different crystallographic planes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000269077000003 Publication Date 2009-08-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0957-4484;1361-6528; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.44 Times cited 14 Open Access  
  Notes Approved Most recent IF: 3.44; 2009 IF: 3.137  
  Call Number UA @ lucian @ c:irua:78933 Serial 588  
Permanent link to this record
 

 
Author Tkachenko, D.V.; Misko, V.R.; Peeters, F.M. url  doi
openurl 
  Title Dynamics of colloids in a narrow channel driven by a nonuniform force Type A1 Journal article
  Year 2009 Publication Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics Abbreviated Journal Phys Rev E  
  Volume 80 Issue 5 Pages 051401,1-051401,10  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using Brownian dynamics simulations, we investigate the dynamics of colloids confined in two-dimensional narrow channels driven by a nonuniform force Fdr(y). We considered linear-gradient, parabolic, and deltalike driving-force profiles. This driving force induces melting of the colloidal solid (i.e., shear-induced melting), and the colloidal motion experiences a transition from elastic to plastic regime with increasing Fdr. For intermediate Fdr (i.e., in the transition region) the response of the system, i.e., the distribution of the velocities of the colloidal chains õi(y), in general does not coincide with the profile of the driving force Fdr(y), and depends on the magnitude of Fdr, the width of the channel, and the density of colloids. For example, we show that the onset of plasticity is first observed near the boundaries while the motion in the central region is elastic. This is explained by: (i) (in)commensurability between the chains due to the larger density of colloids near the boundaries, and (ii) the gradient in Fdr. Our study provides a deeper understanding of the dynamics of colloids in channels and could be accessed in experiments on colloids (or in dusty plasma) with, e.g., asymmetric channels or in the presence of a gradient potential field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000272309500045 Publication Date 2009-11-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1539-3755;1550-2376; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.366 Times cited 14 Open Access  
  Notes Approved Most recent IF: 2.366; 2009 IF: 2.400  
  Call Number UA @ lucian @ c:irua:80313 Serial 774  
Permanent link to this record
 

 
Author Milošević, M.V.; Peeters, F.M. doi  openurl
  Title Vortex manipulation in a superconducting matrix with view on applications Type A1 Journal article
  Year 2010 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 96 Issue 19 Pages 192501,1-192501,3  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We show how a single flux quantum can be effectively manipulated in a superconducting film with a matrix of blind holes. Such a sample can serve as a basic memory element, where the position of the vortex in a k×l matrix of pinning sites defines the desired combination of n bits of information (2n = k×l). Vortex placement is achieved by strategically applied current and the resulting position is read out via generated voltage between metallic contacts on the sample. Such a device can also act as a controllable source of a nanoengineered local magnetic field for, e.g., spintronics applications.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000277756400040 Publication Date 2010-05-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 14 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the ESF-NES and ESF-AQDJJ networks. ; Approved Most recent IF: 3.411; 2010 IF: 3.841  
  Call Number UA @ lucian @ c:irua:83657 Serial 3869  
Permanent link to this record
 

 
Author Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K. pdf  doi
openurl 
  Title Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study Type A1 Journal article
  Year 2010 Publication Applied catalysis : A : general Abbreviated Journal Appl Catal A-Gen  
  Volume 381 Issue 1/2 Pages 242-252  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000279100700029 Publication Date 2010-04-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0926-860X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.339 Times cited 14 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 4.339; 2010 IF: 3.384  
  Call Number UA @ lucian @ c:irua:83927 Serial 2522  
Permanent link to this record
 

 
Author Liu, Y.; Cheng, F.; Li, X.J.; Peeters, F.M.; Chang, K. url  doi
openurl 
  Title Tuning of the two electron states in quantum rings through the spin-orbit interaction Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 82 Issue 4 Pages 1-7  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The effect of the Coulomb interaction on the energy spectrum and anisotropic distribution of two electron states in a quantum ring in the presence of Rashba spin-orbit interaction (RSOI) and Dresselhaus SOI (DSOI) is investigated in the presence of a perpendicular magnetic field. We find that the interplay between the RSOI and DSOI makes the single quantum ring behaves like a laterally coupled quantum dot and the interdot coupling can be tuned by changing the strengths of the SOIs. The interplay can lead to singlet-triplet state mixing and anticrossing behavior when the singlet and triplet states meet with increasing magnetic field. The two electron ground state displays a bar-bell-like spatial anisotropic distribution in a quantum ring at a specific crystallographic direction, i.e., [110] or [11̅ 0], which can be switched by reversing the direction of the perpendicular electric field. The ground state exhibits a singlet-triplet state transition with increasing magnetic field and strengths of RSOI and DSOI. An anisotropic electron distribution is predicted which can be detected through the measurement of its optical properties.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000280234100006 Publication Date 2010-07-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes ; This work was supported by NSFC under Grants No. 60525405 and No. 10874175 and the Belgium Science Policy (IAP). ; Approved Most recent IF: 3.836; 2010 IF: 3.774  
  Call Number UA @ lucian @ c:irua:84087 Serial 3756  
Permanent link to this record
 

 
Author Georgieva, V.; Voter, A.F.; Bogaerts, A. doi  openurl
  Title Understanding the surface diffusion processes during magnetron sputter-deposition of complex oxide Mg-Al-O thin films Type A1 Journal article
  Year 2011 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 11 Issue 6 Pages 2553-2558  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract It is known that film structure may change dramatically with the extent of surface diffusion during the film growth process. In the present work, surface diffusion, induced thermally or activated by energetic impacts, is investigated theoretically under conditions appropriate for magnetron sputter-deposition of MgAlO thin films with varying stoichiometry. The distribution of surface diffusion energy barriers available to the system was determined for each stoichiometry, which allowed assessing in a qualitative way how much surface diffusion will take place on the time scale available between deposition events. The activation energy barriers increase with the Al concentration in the film, and therefore, the surface diffusion rates in the time frame of typical deposition rates drop, which can explain the decrease in crystallinity in the film structure and the transition to amorphous structure. The deposition process and the immediate surface diffusion enhanced by the energetic adatoms are simulated by means of a molecular dynamics model. The longer-time thermal surface diffusion and the energy landscape are studied by the temperature accelerated dynamics method, applied in an approximate way. The surface diffusion enhanced by the energetic impacts appears to be very important for the film structure in the low-temperature deposition regime.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000291074600068 Publication Date 2011-04-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483;1528-7505; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.055 Times cited 14 Open Access  
  Notes Approved Most recent IF: 4.055; 2011 IF: 4.720  
  Call Number UA @ lucian @ c:irua:89566 Serial 3806  
Permanent link to this record
 

 
Author Dachraoui, W.; Yang, T.; Liu, C.; Ling, G.; Hadermann, J.; Van Tendeloo, G.; Llobet, A.; Greenblatt, M. pdf  doi
openurl 
  Title Short-range layered A-site ordering in double perovskites NaLaBB'O6 (B = Mn, Fe; B' = Nb, Ta) Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 9 Pages 2398-2406  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The new compounds NaLaFeTaO6, NaLaFeNbO6, NaLaMnTaO6, and NaLaMnNbO6 have been synthesized and characterized with a combination of transmission electron microscopy, X-ray powder diffraction (XRPD), neutron powder diffraction (NPD), and magnetization measurements. Through electron microscopy study, a local layered order of the A-cations has been detected without the typical occurrence of rock salt order at the B-cation site. Satellite reflections in the electron diffraction related to the local layered order are not visible on the XRPD or NPD patterns. The occurrence of local layered order is supported by pair distribution function analysis, which also reveals the presence of uncorrelated displacements of the Nb and Ta cations. The octahedra are tilted according to the system a−b+a−, and the coordinates were refined from XRPD and NPD with a disordered cation distribution in the space group Pnma. The magnetic exchange interactions in NaLaFeTaO6 and NaLaFeNbO6 are antiferromagnetic, while they are ferromagnetic in NaLaMnTaO6 and NaLaMnNbO6. Long-range magnetic ordering is not observed down to 4 K for any of the compositions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000290063600016 Publication Date 2011-04-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 14 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:89944 Serial 2996  
Permanent link to this record
 

 
Author Scipioni, R.; Matsubara, M.; Ruiz, E.; Massobrio, C.; Boero, M. doi  openurl
  Title Thermal behavior of Si-doped fullerenes vs their structural stability at T = 0 K : a density functional study Type A1 Journal article
  Year 2011 Publication Chemical physics letters Abbreviated Journal Chem Phys Lett  
  Volume 510 Issue 1/3 Pages 14-17  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We establish the topological conditions underlying the thermal stability of C30Si30 clusters. Two topologies have been considered: a segregated one, where Si and C atoms lie on neighboring and yet, separated parts of the cage, and a non-segregated one, where the number of SiC bonds is maximized. The segregated network is energetically favored against the non-segregated one, both structures being fully relaxed at T = 0 K. Conversely, the non-segregated structure is the only one stable at finite temperatures, regardless of the nature of the local states (d or p) included in the KleynmanBylander construction.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000291478400002 Publication Date 2011-05-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0009-2614; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.815 Times cited 14 Open Access  
  Notes Approved Most recent IF: 1.815; 2011 IF: 2.337  
  Call Number UA @ lucian @ c:irua:90453 Serial 3625  
Permanent link to this record
 

 
Author Orlinskii, S.B.; Bogomolov, R.S.; Kiyamova, A.M.; Yavkin, B.V.; Mamin, G.M.; Turner, S.; Van Tendeloo, G.; Shiryaev, A.A.; Vlasov, I.I.; Shenderova, O. pdf  doi
openurl 
  Title Identification of substitutional nitrogen and surface paramagnetic centers in nanodiamond of dynamic synthesis by electron paramagnetic resonance Type A1 Journal article
  Year 2011 Publication Nanoscience and nanotechnology letters Abbreviated Journal Nanosci Nanotech Let  
  Volume 3 Issue 1 Pages 63-67  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Production of nanodiamond particles containing substitutional nitrogen is important for a wide variety of advanced applications. In the current work nanodiamond particles synthesized from a mixture of graphite and hexogen were analyzed to determine the presence of substitutional nitrogen using pulsed electron paramagnetic resonance (EPR) spectroscopy. Nitrogen paramagnetic centers in the amount of 1.2 ppm have been identified. The spin relaxation characteristics for both nitrogen and surface defects are also reported. A new approach for efficient depletion of the strong non-nitrogen EPR signal in nanodiamond material by immersing nanodiamond particles into ice matrix is suggested. This approach allows an essential decrease of the spin relaxation time of the dominant non-nitrogen defects, while preserving the substitutional nitrogen spin relaxation time.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000293211200012 Publication Date 2011-09-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1941-4900;1941-4919; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.889 Times cited 14 Open Access  
  Notes Approved Most recent IF: 1.889; 2011 IF: 0.528  
  Call Number UA @ lucian @ c:irua:91943 Serial 1548  
Permanent link to this record
 

 
Author Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.; Axt, V.M. url  doi
openurl 
  Title Parity-fluctuation induced enlargement of the ratio \DeltaE/kBTc in metallic grains Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 21 Pages 214518-214518,12  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate how the interplay of quantum confinement and particle number-parity fluctuations affects superconducting correlations in ultra-small metallic grains. Using the number-parity projected BCS formalism we calculate the critical temperature and the excitation gap as a function of the grain size for grains with even and odd number of confined carriers. We show that the experimentally observed anomalous increase of the coupling ratio ΔE/kBTc with decreasing superconducting grain size can be attributed to an enhancement of the number-parity fluctuations in ultra-small grains.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000298114100003 Publication Date 2011-12-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes ; This work was supported by the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flamish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). M. D. C. thanks A. S. Mel'nikov and N. B. Kopnin for fruitful discussions. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:94373 Serial 2555  
Permanent link to this record
 

 
Author Chernov, S.V.; Dobrovolsky, Y.A.; Istomin, S.Y.; Antipov, E.V.; Grins, J.; Svensson, G.; Tarakina, N.V.; Abakumov, A.M.; Van Tendeloo, G.; Eriksson, S.G.; Rahman, S.M.H.; pdf  doi
openurl 
  Title _Sr{2}GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5 : a play in the octahedra to tetrahedra ratio in oxygen-deficient perovskites Type A1 Journal article
  Year 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 51 Issue 2 Pages 1094-1103  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Three different perovskite-related phases were isolated in the SrGa(1-x)Sc(x)O(2.5) system: Sr(2)GaScO(5), Sr(10)Ga(6)Sc(4)O(25), and SrGa(0.75)Sc(0.25)O(2.5), Sr(2)GaScO(5) (x = 0.5) crystallizes in a brownrnillerite-type structure [space group (S.G.) Icmm, a = 5.91048(5) angstrom, b = 15.1594(1) angstrom, and c = 5.70926(4) angstrom] with complete ordering of Sc(3+) and Ga(3+) over octahedral and tetrahedral positions, respectively. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) (x = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. I4(1)/a, a = 17.517(1) angstrom, c = 32.830(3) angstrom]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) can be described as a stacking of eight perovskite layers along the c axis ...[-(Sc/Ga)O(1.6)-SrO(0.8)-(Sc/Ga)O(1.8)-SrO(0.8)-](2 center dot center dot center dot) Similar to Sr(2)GaScO(5), this structure features a complete ordering of the Sc(3+) and Ga(3+) cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr(10)Ga(6)Sc(4)O(25) is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc(3+) by Ga(3+) leads to the formation of the cubic perovskite phase SrGa(0.75)Sc(0.25)O(2.5) (x = 0.25) with a = 3.9817(4) angstrom. This compound incorporates water molecules in the structure forming SrGa(0.75)Sc(0.25)O(2.5)center dot xH(2)O hydrate, which exhibits a proton conductivity of similar to 2.0 x 10(-6) S/cm at 673 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000299028800042 Publication Date 2011-12-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0020-1669;1520-510X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 14 Open Access  
  Notes Approved Most recent IF: 4.857; 2012 IF: 4.593  
  Call Number UA @ lucian @ c:irua:96229 Serial 3559  
Permanent link to this record
 

 
Author Özen, M.; Mertens, M.; Luyten, J.; Snijkers, F.; d' Hondt, H.; Cool, P. pdf  doi
openurl 
  Title Hydrothermal synthesis of carbonate-free submicron-sized barium titanate from an amorphous precursor : synthesis and characterization Type A1 Journal article
  Year 2012 Publication Ceramics international Abbreviated Journal Ceram Int  
  Volume 38 Issue 1 Pages 619-625  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)  
  Abstract In this paper, the amorphous barium titanate precursor was prepared by the peroxo-hydroxide method and post-treated by various drying procedures, such as: room temperature drying, room temperature vacuum drying and vacuum drying at 50 degrees C. The objective in the latter two treatments was to increase the Ti-O-Ba bonds of the precursor. The post-treated precursors were compared with the untreated (i.e., 'wet') precursor. Also, a barium titanate precursor was prepared by an alkoxide route. Afterwards, the precursors were hydrothermally treated at 200 degrees C in a 10 M NaOH solution. Vacuum drying of the precursor seemingly promoted the formation of Ti-O-Ti bonds in the hydrothermal end-product. The low Ba:Ti ratio (0.66) of the alkoxide-route prepared precursor lead to a multi-phase hydrothermal product with BaTiO(3) as the main phase. In contrast, phase pure BaTiO(3), i.e. without BaCO(3) contamination, was obtained for the precursor which was dried at room temperature. Cube-shaped and highly crystalline BaTiO(3) particles were observed by electron microscopy for the hydrothermally treated peroxo-hydroxide-route prepared precursor. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Barking Editor  
  Language Wos 000298766900083 Publication Date 2011-08-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0272-8842; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.986 Times cited 14 Open Access  
  Notes Approved Most recent IF: 2.986; 2012 IF: 1.789  
  Call Number UA @ lucian @ c:irua:96263 Serial 1541  
Permanent link to this record
 

 
Author Berdiyorov, G.R.; Hernández-Nieves, A.D.; Milošević, M.V.; Peeters, F.M.; Dominguez, D. url  doi
openurl 
  Title Flux-quantum-discretized dynamics of magnetic flux entry, exit, and annihilation in current-driven mesoscopic type-I superconductors Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 9 Pages 092502-092502,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study nonlinear flux dynamics in a current-carrying type-I superconductor. The stray magnetic field of the current induces the intermediate state, where nucleation of flux domains is discretized to a single fluxoid at a time, while their final shape (tubular or laminar), size, and nucleation rate depend on applied current and edge conditions. The current induces opposite flux domains on opposite sides of the sample, and subsequently drives them to annihilation-which is also discretized, as a sequence of vortex-antivortex pairs. The discretization of both nucleation and annihilation leaves measurable traces in the voltage across the sample and in locally probed magnetization. The reported dynamic phenomena thus provide an unambiguous proof of a flux quantum being the smallest building block of the intermediate state in type-I superconductors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000301183000002 Publication Date 2012-03-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes ; This work was supported by the Belgian Science Policy (IAP), the Flemish Science Foundation (FWO-Vl), and the collaborative project FWO-MINCyT (Project No. FW/08/01). G. R. B. and A. D. H acknowledge support from FWO-Vl. A. D. H. and D. D. acknowledge support from CONICET, CNEA, and ANPCyT (Grant No. PICT07-824). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97180 Serial 1243  
Permanent link to this record
 

 
Author Govaerts, K.; Sluiter, M.H.F.; Partoens, B.; Lamoen, D. url  doi
openurl 
  Title Stability of Sb-Te layered structures : first-principles study Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 14 Pages 144114-144114,8  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Using an effective one-dimensional cluster expansion in combination with first-principles electronic structure calculations we have studied the energetics and electronic properties of Sb-Te layered systems. For a Te concentration between 0 and 60 at. % an almost continuous series of metastable structures is obtained consisting of consecutive Sb bilayers next to consecutive Sb2Te3 units, with the general formula (Sb-2)(n)(Sb2Te3)(m) (n, m = 1,2, ... ). Between 60 and 100 at.% no stable structures are found. We account explicitly for the weak van derWaals bonding between Sb bilayers and Sb2Te3 units by using a recently developed functional, which strongly improves the interlayer bonding distances. At T = 0 K, no evidence is found for the existence of two separate single-phase regions delta and gamma and a two-phase region delta + gamma. Metastable compounds with a Te concentration between 0 and 40 at. % are semimetallic, whereas compounds with a Te concentration between 50 and 60 at. % are semiconducting. Compounds with an odd number of Sb layers are metallic and have a much higher formation energy than those with an even number of consecutive Sb layers, thereby favoring the formation of Sb bilayers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000303115400004 Publication Date 2012-04-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 14 Open Access  
  Notes Iwt; Fwo Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:98255 Serial 3129  
Permanent link to this record
 

 
Author Hilber, W.; Helm, M.; Peeters, F.M.; Alavi, K.; Pathak, R.N. url  doi
openurl 
  Title Impurity band and magnetic-field-induced metal-insulator transition in a doped GaAs/AlxGa1-xAs superlattice Type A1 Journal article
  Year 1996 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 53 Issue 11 Pages 6919-6922  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract A combination of infrared spectroscopy and magnetotransport is used to investigate the impurity band and the magnetic-field-induced metal-insulator transition in n-type GaAs/AlxGa1-xAs superlattices. The dropping of the Fermi level from the conduction band into the impurity band upon increasing magnetic field is observed in a sample doped to n=4n(c), where n(c) is the critical density according to the Mott criterion. The metal-insulator transition takes place while the Fermi level is in the impurity band, with no qualitative change from the metallic to the insulating side. Due to the anisotropy of the superlattice band structure, the metal-insulator transition is shifted to higher magnetic field, when the magnetic field is tilted away from the growth axis towards the layer planes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos A1996UC74000018 Publication Date 2002-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.736 Times cited 14 Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:99676 Serial 1571  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: