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Author Euan-Diaz, E.; Herrera-Velarde, S.; Misko, V.R.; Peeters, F.M.; Castaneda-Priego, R. doi  openurl
  Title Structural transitions and long-time self-diffusion of interacting colloids confined by a parabolic potential Type A1 Journal article
  Year 2015 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 142 Issue 142 Pages 024902  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We report on the ordering and dynamics of interacting colloidal particles confined by a parabolic potential. By means of Brownian dynamics simulations, we find that by varying the magnitude of the trap stiffness, it is possible to control the dimension of the system and, thus, explore both the structural transitions and the long-time self-diffusion coefficient as a function of the degree of confinement. We particularly study the structural ordering in the directions perpendicular and parallel to the confinement. Further analysis of the local distribution of the first-neighbors layer allows us to identify the different structural phases induced by the parabolic potential. These results are summarized in a structural state diagram that describes the way in which the colloidal suspension undergoes a structural re-ordering while increasing the confinement. To fully understand the particle dynamics, we take into account hydrodynamic interactions between colloids; the parabolic potential constricts the available space for the colloids, but it does not act on the solvent. Our findings show a non-linear behavior of the long-time self-diffusion coefficient that is associated to the structural transitions induced by the external field. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000348129700053 Publication Date 2015-01-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606;1089-7690; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 7 Open Access  
  Notes ; This work was partially supported by the “Odysseus” Program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), PIFI 3.4 – PROMEP, and CONACyT (Grant Nos. 61418/2007, 102339/2008, Ph.D. scholarship 230171/2010). R.C.-P. also acknowledges financial support provided by the Marcos Moshinsky fellowship 2013-2014. The authors also thank to the General Coordination of Information and Communications Technologies (CGSTIC) at Cinvestav for providing HPC resources on the Hybrid Cluster Super-computer Xiuhcoatl, which have contributed partially to the research results reported in this paper. ; Approved Most recent IF: 2.965; 2015 IF: 2.952  
  Call Number c:irua:123832 Serial 3267  
Permanent link to this record
 

 
Author Van Hoey, S.; Nopens, I.; van der Kwast, J.; Seuntjens, P. doi  openurl
  Title Dynamic identifiability analysis-based model structure evaluation considering rating curve uncertainty Type A1 Journal article
  Year 2015 Publication Journal of hydrologic engineering Abbreviated Journal  
  Volume 20 Issue 5 Pages 04014072  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract When applying hydrological models, different sources of uncertainty are present, and evaluations of model performances should take these into account to assess model outcomes correctly. Furthermore, uncertainty in the discharge observations complicates the model identification, both in terms of model structure and parameterization. In this paper, the authors compare two different lumped model structures (PDM and NAM) considering uncertainty coming from the rating curve. Limits of acceptability for the model simulations were determined based on derived uncertainty bounds of the discharge observations. The authors applied the DYNamic Identifiability Approach (DYNIA) to identify structural failure of both models and to evaluate the configuration of their structures. In general, similar model performances are observed. However, the model structures tend to behave differently in the course of time, as revealed by the DYNIA approach. Based on the analyses performed, the probability based soil storage representation of the PDM model outperforms the NAM structure. The incorporation of the observation error did not prevent the DYNIA analysis to identify potential model structural deficiencies that are limiting the representation of the seasonal variation, primarily indicated by shifting regions of parameter identifiability. As such, the proposed approach is able to indicate where deficiencies are found and model improvement is needed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000353995400002 Publication Date 2014-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1084-0699 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:126056 Serial 7829  
Permanent link to this record
 

 
Author Filippousi, M.; Siafaka, P.I.; Amanatiadou, E.P.; Nanaki, S.G.; Nerantzaki, M.; Bikiaris, D.N.; Vizirianakis, I.S.; Van Tendeloo, G. pdf  doi
openurl 
  Title Modified chitosan coated mesoporous strontium hydroxyapatite nanorods as drug carriers Type A1 Journal article
  Year 2015 Publication Journal of materials chemistry B : materials for biology and medicine Abbreviated Journal J Mater Chem B  
  Volume 3 Issue 3 Pages 5991-6000  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Mesoporous strontium hydroxyapatite (SrHAp) nanorods (NRs) have been successfully synthesized using a simple and efficient chemical route, i.e. the hydrothermal method. Structural and morphological characterization of the as-synthesized SrHAp NRs have been performed by transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). TEM and HAADF-STEM measurements of the NRs reveal the coexistence of longer and shorter particles with the length ranging from 50 nm to 400 nm and a diameter of about 20-40 nm. Electron tomography measurements of the NRs allow us to better visualize the mesopores and their facets. Two model drugs, hydrophobic risperidone and hydrophilic pramipexole, were loaded into the SrHAp NRs. These nanorods were coated using a modified chitosan (CS) with poly(2-hydroxyethyl methacrylate) (PHEMA), in order to encapsulate the drug-loaded SrHAp nanoparticles and reduce the cytotoxicity of the loaded materials. The drug release from neat and encapsulated SrHAp NRs mainly depends on the drug hydrophilicity. Importantly, although neat SrHAp nanorods exhibit some cytotoxicity against Caco-2 cells, the Cs-g-PHEMA-SrHAp drug-loaded nanorods show an acceptable cytocompatibility.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000358065100009 Publication Date 2015-06-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-750X;2050-7518; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.543 Times cited 24 Open Access  
  Notes Approved Most recent IF: 4.543; 2015 IF: 4.726  
  Call Number c:irua:127131 Serial 2161  
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Author Ullah, S.; Hussain, A.; Syed, W.A.; Saqlain, M.A.; Ahmad, I.; Leenaerts, O.; Karim, A. doi  openurl
  Title Band-gap tuning of graphene by Be doping and Be, B co-doping : a DFT study Type A1 Journal article
  Year 2015 Publication RSC advances Abbreviated Journal Rsc Adv  
  Volume 5 Issue 5 Pages 55762-55773  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract First-principles density functional theory (DFT) calculations were carried out to investigate the structural and electronic properties of beryllium (Be) doped and Be and boron (B) co-doped graphene systems. We observed that not only the concentration of impurity atoms is important to tune the band-gap to some desired level, but also the specific substitution sites play a key role. In our system, which consists of 32 atoms, a maximum of 4Be and, in the co-doped state, 2Be and 3B atom substitutions are investigated. Both dopants are electron deficient relative to C atoms and cause the Fermi level to shift downward (p-type doping). A maximum band gap of 1.44 eV can be achieved on incorporation of 4Be atoms. The introduction of Be is more sensitive in terms of geometry and stability than B. However, in opening the energy gap, Be is more effective than B and N (nitrogen). Our results offer the possibility to modify the band-gap of graphene sufficiently for utilization in diverse electronic device applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000357803200018 Publication Date 2015-06-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2046-2069; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.108 Times cited 33 Open Access  
  Notes ; ; Approved Most recent IF: 3.108; 2015 IF: 3.840  
  Call Number c:irua:127167 Serial 216  
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Author Meng, X.; Pant, A.; Cai, H.; Kang, J.; Sahin, H.; Chen, B.; Wu, K.; Yang, S.; Suslu, A.; Peeters, F.M.; Tongay, S.; doi  openurl
  Title Engineering excitonic dynamics and environmental stability of post-transition metal chalcogenides by pyridine functionalization technique Type A1 Journal article
  Year 2015 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 7 Issue 7 Pages 17109-17115  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract http://cmt.ua.ac.be/hsahin/publishedpapers/46.pdf  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos http://cmt.ua.ac.be/hsahin/publishedpapers/46.pdf Publication Date 2015-09-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364 ISBN Additional Links UA library record; http://cmt.ua.ac.be/hsahin/publishedpapers/46.pdf; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 11 Open Access  
  Notes ; ; Approved Most recent IF: 7.367; 2015 IF: 7.394  
  Call Number UA @ lucian @ c:irua:129434 Serial 4175  
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Author Chen, J.-J.; Ke, X.; Van Tendeloo, G.; Meng, J.; Zhou, Y.-B.; Liao, Z.-M.; Yu, D.-P. pdf  doi
openurl 
  Title Magnetotransport across the metal-graphene hybrid interface and its modulation by gate voltage Type A1 Journal article
  Year 2015 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 7 Issue 7 Pages 5516-5524  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The graphene-metal contact is very important for optimizing the performance of graphene based electronic devices. However, it is difficult to probe the properties of the graphene/metal interface directly via transport measurements in traditional graphene lateral devices, because the dominated transport channel is graphene, not the interface. Here, we employ the Au/graphene/Au vertical and lateral hybrid structure to unveil the metal-graphene interface properties, where the transport is dominated by the charge carriers across the interface. The magnetoresistance (MR) of Au/monolayer graphene/Au and Au/stacked two-layered graphene/Au devices is measured and modulated by gate voltage, demonstrating that the interface is a device. The gate-tunable MR is identified from the graphene lying on the SiO2 substrate and underneath the top metal electrode. Our unique structures couple the in-plane and out-of-plane transport and display linear MR with small amplitude oscillations at low temperatures. Under a magnetic field, the electronic coupling between the graphene edge states and the electrode leads to the appearance of quantum oscillations. Our results not only provide a new pathway to explore the intrinsic transport mechanism at the graphene/metal interface but also open up new vistas of magnetoelectronics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000351372400050 Publication Date 2015-02-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 3 Open Access  
  Notes 246791 Countatoms Approved Most recent IF: 7.367; 2015 IF: 7.394  
  Call Number c:irua:125533 Serial 1931  
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Author Monico, L.; Janssens, K.; Cotte, M.; Romani, A.; Sorace, L.; Grazia, C.; Brunetti, B.G.; Miliani, C. pdf  doi
openurl 
  Title Synchrotron-based X-ray spectromicroscopy and electron paramagnetic resonance spectroscopy to investigate the redox properties of lead chromate pigments under the effect of visible light Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 30 Issue 7 Pages 1500-1510  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Light-induced redox processes have been established as the cause of the chromatic alterations of a number of artists' pigments used from the 15th to the 20th century. Despite the fact that a general comprehension of the mechanisms has been provided through the characterization of photo-degraded compounds, both exhaustive information on the wavelength-dependence of the alteration process of the pigments and experimental evidence in how visible light may influence the formation pathways of specific secondary compounds are still lacking. Establishing an analytical protocol for the study of wavelength-dependence of pigments on photo-redox pathways is relevant for the safe illumination of paintings, especially in view of the possible use of spectrally tunable light sources such as white light emitting diodes (WLEDs). In this work, we propose an integrated approach based on a combination of diffuse reflectance UV-visible, synchrotron radiation (SR)-based micro X-ray fluorescence (m-XRF)/X-ray absorption near edge structure (m-XANES) and electron paramagnetic resonance (EPR) spectroscopies to study the photo-redox process of Cr(VI) -> Cr(III) for lead chromate yellows (PbCr1-xSxO4, 0 <= x <= 0.8) under exposure to different monochromatic light. In view of the thin (3-5 mm) alteration layer that is formed at the paint surface after light exposure, SR-based Cr K-edge mu-XANES/mu-XRF analysis was employed to obtain information on the abundance, nature and distribution of the alteration of Cr(III)-compounds at the micrometricscale level. On the other hand, EPR spectroscopy was used as a complementary tool to the SR-based X-ray methods due to its sensitivity for revealing species containing one or more unpaired electrons and for distinguishing different coordination geometries of paramagnetic centers, such as Cr(V)-species. Semi-quantitative indications about the darkening of the paint surface were obtained by UV-Vis spectroscopy. An abundance of reduced Cr down to around 50% was detected at the aged surface of chrome yellow paints. The reduction process was favored not only by wavelengths shorter than 460 nm (i.e., where the pigment shows its maximum absorption) but also by light in the 490-530 nm range. The first evidence of the presence of Cr(V)-intermediates in the Cr(VI) -> Cr(III) reduction reaction allowed the risks of inducing photo-degradation of the 490-530 nm wavelength range to be explained.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000356971900004 Publication Date 2015-04-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited 17 Open Access  
  Notes ; This research was supported by the Italian projects PRIN-(SICH) and PON- (ITACHA) and by Belgian Science Policy project S2-ART (BELSPO S4DA), the GOA “SOLARPAINT” (Research Fund Antwerp University, Belgium) and FWO (Brussels, Belgium) projects no. G.0C12.13, G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments HG18 and HG26). L.S. and L.M. acknowledge the financial support of Ente-CRF and CNR-Short Term Mobility Programme 2013, respectively. ; Approved Most recent IF: 3.379; 2015 IF: 3.466  
  Call Number UA @ admin @ c:irua:127059 Serial 5862  
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Author Ceglia, A.; Nuyts, G.; Meulebroeck, W.; Cagno, S.; Silvestri, A.; Zoleo, A.; Nys, K.; Janssens, K.; Thienpont, H.; Terryn, H. doi  openurl
  Title Iron speciation in soda-lime-silica glass: a comparison of XANES and UV-vis-NIR spectroscopy Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 30 Issue 7 Pages 1552-1561  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Scientific analyses of ancient glasses have been carried out for many years using elemental chemical analysis. However, it is known that the control of the redox conditions in the glass melt has a strong implication on the final hue of glass because it affects Fe2+/SFe. Therefore an increasing number of studies on the redox conditions have been published in recent years by means of synchrotron based Xray absorption spectroscopy. This is a technique which is not easily accessible and requires dedicated facilities. In this paper we describe an alternative approach by means of optical absorption spectroscopy. We synthesised 10 soda-lime-silica glasses with known redox conditions and iron concentration to calibrate the absorption at 1100 nm as a function of Fe2+ concentration. The linear extinction coefficient was also determined. These glasses were also studied by means of X-ray Absorption Near Edge Structure (XANES) spectroscopy. Electron paramagnetic resonance spectroscopy was additionally used as an ancillary method to verify the quality of our data. Furthermore 28 samples from real archaeological samples were analysed by XANES and optical spectroscopy as a case study. The Fe2+/SFe values obtained were compared and demonstrated that the two techniques were in good agreement with each other. Optical spectroscopy can be applied in situ with moderate sample preparation to determine the concentration of Fe2+. To investigate the redox conditions, especially as a first screening approach, this methodology is an important tool to take into consideration before applying more sophisticated techniques such as XANES, which is more elaborate and requires high-tech resources.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000356971900009 Publication Date 2015-04-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited 20 Open Access  
  Notes ; The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. 265010. For more information please visit the NARNIA website: http:// narnia-itn.eu/. This work was partly supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/ F50. We are grateful to the ESRF for granting beamtime and Dipanjan Banerjee for his help at the beamline. We are thankful to the R&D department of AGC Glass Europe, in particular Dr Benoit Cherdon, Dr Dominique Michiels and Ms Dominique Delleuze, for preparing glass for us and providing us the chemical information. A special thanks to M. Fialin for the help with EPMA measurements in CAMPARIS. We want to express our gratitude to F. Farges and A. Berry for sharing their XANES spectra with us. Thanks to Anne Isabelle for reading this paper and giving comments. Finally we are grateful to two anonymous reviewers who contributed to improve this paper. ; Approved Most recent IF: 3.379; 2015 IF: 3.466  
  Call Number UA @ admin @ c:irua:127060 Serial 5679  
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Author Tirez, K.; Vanhoof, C.; Bronders, J.; Seuntjens, P.; Bleux, N.; Berghmans, P.; De Brucker, N.; Vanhaecke, F. doi  openurl
  Title Do ICP-MS based methods fulfill the EU monitoring requirements for the determination of elements in our environment? Type A1 Journal article
  Year 2015 Publication Environmental science : processes & impacts Abbreviated Journal  
  Volume 17 Issue 12 Pages 2034-2050  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Undoubtedly, the most important advance in the environmental regulatory monitoring of elements of the last decade is the widespread introduction of ICP-mass spectrometry (ICP-MS) due to standards developed by the European Committee for Standardization. The versatility of ICP-MS units as a tool for the determination of major, minor and trace elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, Ti, V and Zn) in surface water, groundwater, river sediment, topsoil, subsoil, fine particulates and atmospheric deposition is illustrated in this paper. Ranges of background concentrations for major, minor and trace elements obtained from a regional case study (Flanders, Belgium) are summarized for all of these environmental compartments and discussed in the context of a harmonized implementation of European regulatory monitoring requirements. The results were derived from monitoring programs in support of EU environmental quality directives and were based on a selection of (non-polluted) background locations. Because of the availability of ICP-MS instruments nowadays, it can be argued that the main hindrance for meeting the European environmental monitoring requirements is no longer the technical feasibility of analysis at these concentration levels, but rather (i) potential contamination during sampling and analysis, (ii) too limited implementation of quality control programs, validating the routinely applied methods (including sampling and low level verification) and (iii) lack of harmonization in reporting of the chemical environmental status between the individual member states.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000365915600005 Publication Date 2015-10-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7887; 2050-7895 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:130316 Serial 7821  
Permanent link to this record
 

 
Author Van de Vijver, E.; Van Meirvenne, M.; Vandenhaute, L.; Delefortrie, S.; De Smedt, P.; Saey, T.; Seuntjens, P. doi  openurl
  Title Urban soil exploration through multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar Type A1 Journal article
  Year 2015 Publication Environmental science : processes & impacts Abbreviated Journal  
  Volume 17 Issue 7 Pages 1271-1281  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract In environmental assessments, the characterization of urban soils relies heavily on invasive investigation, which is often insufficient to capture their full spatial heterogeneity. Non-invasive geophysical techniques enable rapid collection of high-resolution data and provide a cost-effective alternative to investigate soil in a spatially comprehensive way. This paper presents the results of combining multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar to characterize a former garage site contaminated with petroleum hydrocarbons. The sensor combination showed the ability to identify and accurately locate building remains and a high-density soil layer, thus demonstrating the high potential to investigate anthropogenic disturbances of physical nature. In addition, a correspondence was found between an area of lower electrical conductivity and elevated concentrations of petroleum hydrocarbons, suggesting the potential to detect specific chemical disturbances. We conclude that the sensor combination provides valuable information for preliminary assessment of urban soils.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000357793300008 Publication Date 2015-06-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7887; 2050-7895 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:127130 Serial 8715  
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Author Charkin, D.O.; Akinfiev, V.S.; Alekseeva, A.M.; Batuk, M.; Abakumov, A.M.; Kazakov, S.M. doi  openurl
  Title Synthesis and cation distribution in the new bismuth oxyhalides with the Sillen-Aurivillius intergrowth structures Type A1 Journal article
  Year 2015 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T  
  Volume 44 Issue 44 Pages 20568-20576  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract About 20 new compounds with the Sillen-Aurivillius intergrowth structure, (MeMeBi3Nb2O11X)-Me-1-Bi-2 (Me-1 = Pb, Sr, Ba; Me-2 = Ca, Sr, Ba; X = Cl, Br, I), have been prepared. They are composed of stacking of [ANb(2)O(7)] perovskite blocks, fluorite-type [M2O2] blocks and halogen sheets. The cation distribution between the fluorite and perovskite layers has been studied for Ba2Bi3Nb2O11I, Ca1.25Sr0.75Bi3Nb2O11Cl, BaCaBi3Nb2O11Br and Sr2Bi3Nb2O11Cl. The smaller Me cations tend to reside in the perovskite block while the larger ones are situated in the fluorite-type block. The distribution of the elements was confirmed for BaCaBi3Nb2O11Br using energy dispersive X-ray analysis combined with scanning transmission electron microscopy (STEM-EDX). An electron diffraction study of this compound reveals a local symmetry lowering caused by weakly correlated rotation of NbO6 octahedra. Based on our findings, we suggest a new stability criterion for mixed-layer structures, which is that net charges of any two consecutive layers do not compensate for each other and only the whole layer sequence is electroneutral.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000365411500036 Publication Date 2015-10-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0300-9246; 1477-9226; 1472-7773 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.029 Times cited 5 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:130330 Serial 4256  
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Author Çakir, D.; Kecik, D.; Sahin, H.; Durgun, E.; Peeters, F.M. pdf  doi
openurl 
  Title Realization of a p-n junction in a single layer boron-phosphide Type A1 Journal article
  Year 2015 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 17 Issue 17 Pages 13013-13020  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Two-dimensional (2D) materials have attracted growing interest due to their potential use in the next generation of nanoelectronic and optoelectronic applications. On the basis of first-principles calculations based on density functional theory, we first investigate the electronic and mechanical properties of single layer boron phosphide (h-BP). Our calculations show that h-BP is a mechanically stable 2D material with a direct band gap of 0.9 eV at the K-point, promising for both electronic and optoelectronic applications. We next investigate the electron transport properties of a p-n junction constructed from single layer boron phosphide (h-BP) using the non-equilibrium Green's function formalism. The n-and p-type doping of BP are achieved by substitutional doping of B with C and P with Si, respectively. C(Si) substitutional doping creates donor (acceptor) states close to the conduction (valence) band edge of BP, which are essential to construct an efficient p-n junction. By modifying the structure and doping concentration, it is possible to tune the electronic and transport properties of the p-n junction which exhibits not only diode characteristics with a large current rectification but also negative differential resistance (NDR). The degree of NDR can be easily tuned via device engineering.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000354195300065 Publication Date 2015-04-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 104 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem foundation of the Flemish government and the Bilateral program FWO-TUBITAK (under the Project No. 113T050) between Flanders and Turkey. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. H.S. is supported by a FWO Pegasus Marie Curie-long Fellowship. E.D. acknowledges support from Bilim Akademisi – The Science Academy, Turkey under the BAGEP program. ; Approved Most recent IF: 4.123; 2015 IF: 4.493  
  Call Number c:irua:126394 Serial 2835  
Permanent link to this record
 

 
Author Barreca, D.; Carraro, G.; Warwick, M.E.A.; Kaunisto, K.; Gasparotto, A.; Gombac, V.; Sada, C.; Turner, S.; Van Tendeloo, G.; Maccato, C.; Fornasiero, P.; doi  openurl
  Title Fe2O3-TiO2 nanosystems by a hybrid PE-CVD/ALD approach : controllable synthesis, growth mechanism, and photocatalytic properties Type A1 Journal article
  Year 2015 Publication CrystEngComm Abbreviated Journal Crystengcomm  
  Volume 17 Issue 17 Pages 6219-6226  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Supported Fe2O3–TiO2 nanocomposites are fabricated by an original vapor phase synthetic strategy, consisting of the initial growth of Fe2O3 nanosystems on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition, followed by atomic layer deposition of TiO2 overlayers with variable thickness, and final thermal treatment in air. A thorough characterization of the target systems is carried out by X-ray diffraction, atomic force microscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. High purity nanomaterials characterized by the co-presence of Fe2O3 (hematite) and TiO2 (anatase), with an intimate Fe2O3–TiO2 contact, are successfully obtained. In addition, photocatalytic tests demonstrate that, whereas both single-phase oxides do not show appreciable activity, the composite systems are able to degrade methyl orange aqueous solutions under simulated solar light, and even visible light, with an efficiency directly dependent on TiO2 overlayer thickness. This finding opens attractive perspectives for eventual applications in wastewater treatment.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000358915300018 Publication Date 2015-07-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1466-8033; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.474 Times cited 25 Open Access  
  Notes The research leading to these results has received funding from the FP7 project “SOLAROGENIX” IJNMP4-SL-2012- 310333), as well as from Padova University ex-60% 2012–2015 projects, grant no. CPDR132937/13 (SOLLEONE), and Regione Lombardia-INSTM ATLANTE projects. S. T. acknowledges the FWO Flanders for a post-doctoral scholarship. Thanks are also due to Prof. S. Mathur and Dr. Y. Gönüllü (Department of Chemistry, Cologne University, Germany) for their precious help and assistance in ALD depositions, and to Prof. E. Bontempi (Chemistry for Technologies Laboratory, Brescia University, Italy) for XRD analyses. Approved Most recent IF: 3.474; 2015 IF: 4.034  
  Call Number c:irua:127237 Serial 3531  
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Author Struzzi, C.; Erbahar, D.; Scardamaglia, M.; Amati, M.; Gregoratti, L.; Lagos; Van Tendeloo, G.; Snyders, R.; Ewels, C.; Bittencourt, C. doi  openurl
  Title Selective decoration of isolated carbon nanotubes by potassium evaporation : scanning photoemission microscopy and density functional theory Type A1 Journal article
  Year 2015 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C  
  Volume 3 Issue 3 Pages 2518-2527  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Site selective doping of aligned carbon nanostructures represents a promising approach for their implementation in actual devices. In the present work we report on alkali metals decoration on low density vertically aligned carbon nanotubes, disclosing the possibility of engineering site selective depositions of potassium atoms on the carbon systems. Photoemission measurements were combined with microscopy demonstrating the effective spatial control of alkali deposition. The changes of electronic structures of locally doped carbon regions were studied by exploiting the ability of the scanning photoemission microscopy technique. From the analysis of experimental data supported by theoretical calculations, we show the tuning of the charge transfer from potassium to carbon atoms belonging to neighboring nanotubes or along the same tube structure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000350984200011 Publication Date 2014-12-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7526;2050-7534; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.256 Times cited 6 Open Access  
  Notes Approved Most recent IF: 5.256; 2015 IF: 4.696  
  Call Number c:irua:125496 Serial 2963  
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Author Leus, K.; Concepcion, P.; Vandichel, M.; Meledina, M.; Grirrane, A.; Esquivel, D.; Turner, S.; Poelman, D.; Waroquier, M.; Van Speybroeck, V.; Van Tendeloo, G.; García, H.; Van Der Voort, P.; pdf  doi
openurl 
  Title Au@UiO-66 : a base free oxidation catalyst Type A1 Journal article
  Year 2015 Publication RSC advances Abbreviated Journal Rsc Adv  
  Volume 5 Issue 5 Pages 22334-22342  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We present the in situ synthesis of Au nanoparticles within the Zr based Metal Organic Framework, UiO-66. The resulting Au@UiO-66 materials were characterized by means of N-2 sorption, XRPD, UV-Vis, XRF, XPS and TEM analysis. The Au nanoparticles (NP) are homogeneously distributed along the UiO-66 host matrix when using NaBH4 or H-2 as reducing agents. The Au@UiO-66 materials were evaluated as catalysts in the oxidation of benzyl alcohol and benzyl amine employing O-2 as oxidant. The Au@MOF materials exhibit a very high selectivity towards the ketone (up to 100%). Regenerability and stability tests demonstrate that the Au@UiO-66 catalyst can be recycled with a negligible loss of Au species and no loss of crystallinity. In situ IR measurements of UiO-66 and Au@UiO-66-NaBH4, before and after treatment with alcohol, showed an increase in IR bands that can be assigned to a combination of physisorbed and chemisorbed alcohol species. This was confirmed by velocity power spectra obtained from the molecular dynamics simulations. Active peroxo and oxo species on Au could be visualized with Raman analysis.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000350643700005 Publication Date 2015-02-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2046-2069; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.108 Times cited 38 Open Access  
  Notes FWO; Hercules; 246791 COUNTATOMS; IAP-PAI Approved Most recent IF: 3.108; 2015 IF: 3.840  
  Call Number c:irua:125431 Serial 207  
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Author Meledina, M.; Turner, S.; Galvita, V.V.; Poelman, H.; Marin, G.B.; Van Tendeloo, G. doi  openurl
  Title Local environment of Fe dopants in nanoscale Fe : CeO2-x oxygen storage material Type A1 Journal article
  Year 2015 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 7 Issue 7 Pages 3196-3204  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Nanoscale Fe : CeO2-x oxygen storage material for the process of chemical looping has been investigated by advanced transmission electron microscopy and electron energy-loss spectroscopy before and after a model looping procedure, consisting of redox cycles at heightened temperature. Separately, the activity of the nanomaterial has been tested in a toluene total oxidation reaction. The results show that the material consists of ceria nanoparticles, doped with single Fe atoms and small FeOx clusters. The iron ion is partially present as Fe3+ in a solid solution within the ceria lattice. Furthermore, enrichment of reduced Fe2+ species is observed in nanovoids present in the ceria nanoparticles, as well as at the ceria surface. After chemical looping, agglomeration occurs and reduced nanoclusters appear at ceria grain boundaries formed by sintering. These clusters originate from surface Fe2+ aggregation, and from bulk Fe3+, which “leaks out” in reduced state after cycling to a slightly more agglomerated form. The activity of Fe : CeO2 during the toluene total oxidation part of the chemical looping cycle is ensured by the dopant Fe in the Fe1-xCexO2 solid solution, and by surface Fe species. These measurements on a model Fe : CeO2-x oxygen storage material give a unique insight into the behavior of dopants within a nanosized ceria host, and allow to interpret a plethora of (doped) cerium oxide-based reactions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000349473200046 Publication Date 2015-01-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 17 Open Access  
  Notes Approved Most recent IF: 7.367; 2015 IF: 7.394  
  Call Number c:irua:125299 Serial 1828  
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Author Silva, A.L.M.; Carvalho, M.L.; Janssens, K.; Veloso, J.F.C.A. pdf  doi
openurl 
  Title A large area full-field EDXRF imaging system based on a THCOBRA gaseous detector Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 30 Issue 2 Pages 343-352  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract By taking advantage of the attractive features in terms of gain, position and energy resolution of the 2D-THCOBRA detector, a new large area Full-Field X-ray Fluorescence Imaging (FF-XRFI) system for EDXRF imaging applications was developed. The proposed FF-XRFI system has an active area of 10 x 10 cm(2) and can be used to examine macroscopic samples with a moderately good energy resolution (< 1.6 keV FWHM at 8 keV) and a suitable spatial resolution (similar to 500 mu m FWHM). This combination of characteristics allows us to record elemental distribution maps from the surface of different sample types by combining image and energy information. Two different approaches were used for X-ray optics, one based on a single pinhole and another based on a parallel multiple-hole collimator. To illustrate the system capabilities, some sample examples were imaged and studied.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000349145700003 Publication Date 2014-10-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited 11 Open Access  
  Notes ; The authors thank Stijn Legrand for acquisition of the MAXRF maps shown in Fig. 15. This work was partially supported by projects CERN/FP/123604/2011 FEDER, COMPETE and FCT (Lisbon) programs. A. L. M. Silva is supported by the QREN programme Mais Centro – Programa Operacional Regional do Centro, FEDER and COMPETE, through the project Biomaterials for Regenerative Medicine (CENTRO-07-ST24-FEDER-002030). ; Approved Most recent IF: 3.379; 2015 IF: 3.466  
  Call Number UA @ admin @ c:irua:125297 Serial 5452  
Permanent link to this record
 

 
Author Cambré, S.; Campo, J.; Beirnaert, C.; Verlackt, C.; Cool, P.; Wenseleers, W. pdf  doi
openurl 
  Title Asymmetric dyes align inside carbon nanotubes to yield a large nonlinear optical response Type A1 Journal article
  Year 2015 Publication Nature nanotechnology Abbreviated Journal Nat Nanotechnol  
  Volume 10 Issue 10 Pages 248-252  
  Keywords A1 Journal article; Engineering sciences. Technology; Nanostructured and organic optical and electronic materials (NANOrOPT); Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Asymmetric dye molecules have unusual optical and electronic properties1, 2, 3. For instance, they show a strong second-order nonlinear optical (NLO) response that has attracted great interest for potential applications in electro-optic modulators for optical telecommunications and in wavelength conversion of lasers2, 3. However, the strong Coulombic interaction between the large dipole moments of these molecules favours a pairwise antiparallel alignment that cancels out the NLO response when incorporated into bulk materials. Here, we show that by including an elongated dipolar dye (p,p′-dimethylaminonitrostilbene, DANS, a prototypical asymmetric dye with a strong NLO response4) inside single-walled carbon nanotubes (SWCNTs)5, 6, an ideal head-to-tail alignment in which all electric dipoles point in the same sense is naturally created. We have applied this concept to synthesize solution-processible DANS-filled SWCNTs that show an extremely large total dipole moment and static hyperpolarizability (β0 = 9,800 × 10−30 e.s.u.), resulting from the coherent alignment of arrays of ∼70 DANS molecules.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000350799700016 Publication Date 2015-02-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-3387;1748-3395; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 38.986 Times cited 46 Open Access  
  Notes Approved Most recent IF: 38.986; 2015 IF: 34.048  
  Call Number c:irua:125405 Serial 158  
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Author Yang, S.; Wang, C.; Sahin, H.; Chen, H.; Li, Y.; Li, S.S.; Suslu, A.; Peeters, F.M.; Liu, Q.; Li, J.; Tongay, S.; doi  openurl
  Title Tuning the optical, magnetic, and electrical properties of ReSe2 by nanoscale strain engineering Type A1 Journal article
  Year 2015 Publication Nano letters Abbreviated Journal Nano Lett  
  Volume 15 Issue 15 Pages 1660-1666  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Creating materials with ultimate control over their physical properties is vital for a wide range of applications. From a traditional materials design perspective, this task often requires precise control over the atomic composition and structure. However, owing to their mechanical properties, low-dimensional layered materials can actually withstand a significant amount of strain and thus sustain elastic deformations before fracture. This, in return, presents a unique technique for tuning their physical properties by strain engineering. Here, we find that local strain induced on ReSe2, a new member of the transition metal dichalcogenides family, greatly changes its magnetic, optical, and electrical properties. Local strain induced by generation of wrinkle (1) modulates the optical gap as evidenced by red-shifted photoluminescence peak, (2) enhances light emission, (3) induces magnetism, and (4) modulates the electrical properties. The results not only allow us to create materials with vastly different properties at the nanoscale, but also enable a wide range of applications based on 2D materials, including strain sensors, stretchable electrodes, flexible field-effect transistors, artificial-muscle actuators, solar cells, and other spintronic, electromechanical, piezoelectric, photonic devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington Editor  
  Language Wos 000351188000033 Publication Date 2015-02-02  
  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 314 Open Access  
  Notes ; This work is supported by Arizona State University, Research Seeding Program, the National Natural Science Foundation of China (91233120), and the National Basic Research Program of China (2011CB921901). Q., Liu acknowledges the support to this work by NSFC (10974037), NBRPC (2010CB934102), and the CAS Strategy Pilot program (XDA 09020300). S. Yang acknowledges financial support from China Postdoctoral Science Foundation (No. 2013M540127). ; Approved Most recent IF: 12.712; 2015 IF: 13.592  
  Call Number c:irua:125480 Serial 3758  
Permanent link to this record
 

 
Author Galvan Moya, J.E.; Nelissen, K.; Peeters, F.M. pdf  doi
openurl 
  Title Structural ordering of self-assembled clusters with competing interactions : transition from faceted to spherical clusters Type A1 Journal article
  Year 2015 Publication Langmuir: the ACS journal of surfaces and colloids Abbreviated Journal Langmuir  
  Volume 31 Issue 31 Pages 917-924  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The self-assembly of nanoparticles into clusters and the effect of the different parameters of the competing interaction potential on it are investigated. For a small number of particles, the structural organization of the clusters is almost unaffected by the attractive part of the potential, and for an intermediate number of particles the configuration strongly depends on the strength of it. The cluster size is controlled by the range of the interaction potential, and the structural arrangement is guided by the strength of the potential: i.e., the self-assembled cluster transforms from a faceted configuration at low strength to a spherical shell-like structure at high strength. Nonmonotonic behavior of the cluster size is found by increasing the interaction range. An approximate analytical expression is obtained that predicts the smallest cluster for a specific set of potential parameters. A Mendeleev-like table is constructed for different values of the strength and range of the attractive part of the potential in order to understand the structural ordering of the ground-state configuration of the self-assembled clusters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000348689700005 Publication Date 2014-12-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0743-7463;1520-5827; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.833 Times cited 4 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were provided by the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC). ; Approved Most recent IF: 3.833; 2015 IF: 4.457  
  Call Number c:irua:125292 Serial 3243  
Permanent link to this record
 

 
Author Quan Manh, P.; Pourtois, G.; Swerts, J.; Pierloot, K.; Delabie, A. doi  openurl
  Title Atomic layer deposition of Ruthenium on Ruthenium surfaces : a theoretical study Type A1 Journal article
  Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 119 Issue 119 Pages 6592-6603  
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Atomic, layer deposition,(ALD of ruthenium using two ruthenium precursors, i.e., Ru(C5H5)(2) (RuCp2) and Ru(C5H5)(C4H4N) (RuCpPy), is studied using density functional theory. By investigating the reaction mechanisms On bare ruthenium surfaces, i.e., (001), (101), and (100), and H-terminated surfaces, an atomistic insight in the Ru ALD is provided. The calculated results show that on the Ru surfaces both RuCp2 and RuCpPy an undergo dehydrogenation and ligand dissociation reactions. RuCpPy is more reactive than RuCp2. By forming a, strong, bond between N of Py and Ru of the surface, RuCpPy can easily chemisorb on the surfaces. The reactions of RuCp2,On the Surfaces are less favorable the adsorption is not strong enough This could be a,factor contributing to the higher growth-per-cycle of Ru using RuCpPy, as observed experimentally. By Studying, the adsorption on H-terminated Ru surfaces, We showed that H Can prevent the adsorption of the precursors, thus inhibiting the growth of Ru. Our calculations indicate that the H content on the surface can have an impact on the growth-per-cycle. Finally, our simulations also demonstrate large impacts of the surface structure on the reaction mechanisms. Of the three surfaces, the (100) surface, which is the less stable and has a zigzag surface structure, is also the most reactive one.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000351970800015 Publication Date 2015-03-04  
  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 10 Open Access  
  Notes Approved Most recent IF: 4.536; 2015 IF: 4.772  
  Call Number c:irua:125544 Serial 171  
Permanent link to this record
 

 
Author Esfahani; Leenaerts, O.; Sahin, H.; Partoens, B.; Peeters, F.M. doi  openurl
  Title Structural transitions in monolayer MOS2 by lithium adsorption Type A1 Journal article
  Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 119 Issue 119 Pages 10602-10609  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Based on first-principles calculations, we study the structural stability of the H and T phases of monolayer MoS2 upon Li doping. Our calculations demonstrate that it is possible to stabilize a distorted T phase of MoS2 over the H phase through adsorption of Li atoms on the MoS2 surface. Through molecular dynamics and phonon calculations, we show that the T phase of MoS2 is dynamically unstable and undergoes considerable distortions. The type of distortion depends on the concentration of adsorbed Li atoms and changes from zigzag-like to diamond-like when increasing the Li doping. There exists a substantial energy barrier to transform the stable H phase to the distorted T phases, which is considerably reduced by increasing the concentration of Li atoms. We show that it is necessary that the Li atoms adsorb on both sides of the MoS2 monolayer to reduce the barrier sufficiently. Two processes are examined that allow for such two-sided adsorption, namely, penetration through the MoS2 layer and diffusion over the MoS2 surface. We show that while there is only a small barrier of 0.24 eV for surface diffusion, the amount of energy needed to pass through a pure MoS2 layer is of the order of similar or equal to 2 eV. However, when the MoS2 layer is covered with Li atoms the amount of energy that Li atoms should gain to penetrate the layer is drastically reduced and penetration becomes feasible.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000354912200051 Publication Date 2015-04-07  
  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 96 Open Access  
  Notes ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl) and the Methusalem program of the Flemish government. H. S is supported by an FWO Pegasus-Long Marie Curie fellowship. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government department EWI. ; Approved Most recent IF: 4.536; 2015 IF: 4.772  
  Call Number c:irua:126409 Serial 3270  
Permanent link to this record
 

 
Author McCalla, E.; Sougrati, M.T.; Rousse, G.; Berg, E.J.; Abakumov, A.; Recham, N.; Ramesha, K.; Sathiya, M.; Dominko, R.; Van Tendeloo, G.; Novák, P.; Tarascon, J.M.; doi  openurl
  Title Understanding the roles of anionic redox and oxygen release during electrochemical cycling of lithium-rich layered Li4FeSbO6 Type A1 Journal article
  Year 2015 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 137 Issue 137 Pages 4804-4814  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Li-rich oxides continue to be of immense interest as potential next generation Li-ion battery positive electrodes, and yet the role of oxygen during cycling is still poorly understood. Here, the complex electrochemical behavior of Li4FeSbO6 materials is studied thoroughly with a variety of methods. Herein, we show that oxygen release occurs at a distinct voltage plateau from the peroxo/superoxo formation making this material ideal for revealing new aspects of oxygen redox processes in Li-rich oxides. Moreover, we directly demonstrate the limited reversibility of the oxygenated species (O-2(n-); n = 1, 2, 3) for the first time. We also find that during charge to 4.2 V iron is oxidized from +3 to an unusual +4 state with the concomitant formation of oxygenated species. Upon further charge to 5.0 V, an oxygen release process associated with the reduction of iron +4 to +3 is present, indicative of the reductive coupling mechanism between oxygen and metals previously reported. Thus, in full state of charge, lithium removal is fully compensated by oxygen only, as the iron and antimony are both very close to their pristine states. Besides, this charging step results in complex phase transformations that are ultimately destructive to the crystallinity of the material. Such findings again demonstrate the vital importance of fully understanding the behavior of oxygen in such systems. The consequences of these new aspects of the electrochemical behavior of lithium-rich oxides are discussed in detail.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000353177100036 Publication Date 2015-03-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 86 Open Access  
  Notes Approved Most recent IF: 13.858; 2015 IF: 12.113  
  Call Number c:irua:126019 Serial 3805  
Permanent link to this record
 

 
Author Baken, S.; Salaets, P.; Desmet, N.; Seuntjens, P.; Vanlierde, E.; Smolders, E. doi  openurl
  Title Oxidation of iron causes removal of phosphorus and arsenic from streamwater in groundwater-fed lowland catchments Type A1 Journal article
  Year 2015 Publication Environmental science and technology Abbreviated Journal  
  Volume 49 Issue 5 Pages 2886-2894  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract The fate of iron (Fe) may affect that of phosphorus (P) and arsenic (As) in natural waters. This study addresses the removal of Fe, P, and As from streams in lowland catchments fed by reduced, Fe-rich groundwater (average: 20 mg Fe L-1). The concentrations of dissolved Fe (<0.45 mu m) in streams gradually decrease with increasing hydraulic residence time (travel time) of the water in the catchment. The removal of Fe from streamwater is governed by chemical reactions and hydrological processes: the oxidation of ferrous iron (Fe(II)) and the subsequent formation of particulate Fe oxyhydroxides proceeds as the water flows through the catchment into increasingly larger streams. The Fe removal exhibits first-order kinetics with a mean half-life of 12 h, a value in line with predictions by a kinetic model for Fe(II) oxidation. The Fe concentrations in streams vary seasonally: they are higher in winter than in summer, due to shorter hydraulic residence time and lower temperature in winter. The removal of P and As is much faster than that of Fe. The average concentrations of P and As in streams (42 mu g P L-1) and 1.4 mu g As L-1) are 1 order of magnitude below those in groundwater (393 mu g P L-1 and 17 mu g As L-1). This removal is attributed to fast sequestration by oxidizing Fe when the water enters oxic environments, possibly by adsorption on Fe oxyhydroxides or by formation of ferric phosphates. The average P and As concentrations in groundwater largely exceed local environmental limits for freshwater (140 mu g P L-1 and 3 mu g As L((-1)), but in streams, they are below these limits. Naturally occurring Fe in groundwater may alleviate the environmental risk associated with P and As in the receiving streams.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000350611100040 Publication Date 2015-02-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-936x; 1520-5851 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:125409 Serial 8354  
Permanent link to this record
 

 
Author Chen, B.; Sahin, H.; Suslu, A.; Ding, L.; Bertoni, M.I.; Peeters, F.M.; Tongay, S. doi  openurl
  Title Environmental changes in MoTe2 excitonic dynamics by defects-activated molecular interaction Type A1 Journal article
  Year 2015 Publication ACS nano Abbreviated Journal Acs Nano  
  Volume 9 Issue 9 Pages 5326-5332  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Monolayers of group VI transition metal dichalcogenides possess direct gaps in the visible spectrum with the exception of MoTe2, where its gap is suitably located in the infrared region but its stability is of particular interest, as tellurium compounds are acutely sensitive to oxygen exposure. Here, our environmental (time-dependent) measurements reveal two distinct effects on MoTe2 monolayers: For weakly luminescent monolayers, photoluminescence signal and optical contrast disappear, as if they are decomposed, but yet remain intact as evidenced by AFM and Raman measurements. In contrast, strongly luminescent monolayers retain their optical contrast for a prolonged amount of time, while their PL peak blue-shifts and PL intensity saturates to slightly lower values. Our X-ray photoelectron spectroscopy measurements and DFT calculations suggest that the presence of defects and functionalization of these defect sites with O-2 molecules strongly dictate their material properties and aging response by changing the excitonic dynamics due to deep or shallow states that are created within the optical band gap. Presented results not only shed light on environmental effects on fundamental material properties and excitonic dynamics of MoTe2 monolayers but also highlight striking material transformation for metastable 20 systems such as WTe2, silicone, and phosphorene.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000355383000068 Publication Date 2015-04-14  
  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 150 Open Access  
  Notes ; This work was supported by the Arizona State University seeding program. The authors thank Hui Cai and Kedi Wu for useful discussions. We gratefully acknowledge the use of facilities at the LeRoy Eyring Center for Solid State Science at Arizona State University. This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem Foundation of the Flemish government. H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; Approved Most recent IF: 13.942; 2015 IF: 12.881  
  Call Number c:irua:126441 Serial 1068  
Permanent link to this record
 

 
Author Buffière, M.; Brammertz, G.; Sahayaraj, S.; Batuk, M.; Khelifi, S.; Mangin, D.; El Mel, A.A.; Arzel, L.; Hadermann, J.; Meuris, M.; Poortmans, J.; doi  openurl
  Title KCN chemical etch for interface engineering in Cu2ZnSnSe4 solar cells Type A1 Journal article
  Year 2015 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter  
  Volume 7 Issue 7 Pages 14690-14698  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The removal of secondary phases from the surface of the kesterite crystals is one of the major challenges to improve the performances of Cu2ZnSn(S,Se)(4) (CZTSSe) thin film solar cells. In this Contribution, the KCN/KOH Chemical etching approach, originally developed for the removal of CuxSe phases in Cu(In,Ga)(S,Se)(2) thin films) is applied to CZTSe absorbers exhibiting various chemical compositions. Two distinct electrical behaviors were observed on CZTSe/CdS solar cells after treatment: (i) the improvement of the fill factor (FF) after 30 s of etching for the CZTSe absorbers showing initially a distortion of the electrical characteristic; (ii) the progressive degradation Of the FF after long treatment time for all Cu-poor CZTSe solar cell samples. The first effect can be attributed to the action of KCN on the absorber, that is found to clean the absorber free surface from most of the secondary phases surrounding the kesterite grains (e.g., Se-0, CuxSe, SnSex, SnO2, Cu2SnSe3 phases, excepting the ZnSe-based phases). The second observation was identified as a consequence of the preferential etching of Se, Sn, and Zn from the CZTSe surface by the KOH solution, combined with the modification of the alkali content of the absorber. The formation of a Cu-rich shell at the absorber/buffer layer interface, leading to the increase of the recombination rate at the interface, and the increase in the doping of the absorber layer after etching are found to be at the origin of the deterioration of the FF of the solar cells.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000358395200019 Publication Date 2015-06-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1944-8244;1944-8252; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.504 Times cited 34 Open Access  
  Notes Approved Most recent IF: 7.504; 2015 IF: 6.723  
  Call Number c:irua:127153 Serial 1755  
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Author Warwick, M.E.A.; Kaunisto, K.; Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Bontempi, E.; Sada, C.; Ruoko, T.P.; Turner, S.; Van Tendeloo, G.; pdf  doi
openurl 
  Title Vapor phase processing of \alpha-Fe2O3 photoelectrodes for water splitting : an insight into the structure/property interplay Type A1 Journal article
  Year 2015 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter  
  Volume 7 Issue 7 Pages 8667-8676  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Harvesting radiant energy to trigger water photoelectrolysis and produce clean hydrogen is receiving increasing attention in the search of alternative energy resources. In this regard, hematite (alpha-Fe2O3) nanostructures with controlled nano-organization have been fabricated and investigated for use as anodes in photoelectrochemical (PEC) cells. The target systems have been grown on conductive substrates by plasma enhanced-chemical vapor deposition (PE-CVD) and subjected to eventual ex situ annealing in air to further tailor their structure and properties. A detailed multitechnique approach has enabled to elucidate between system characteristics and the generated photocurrent. The present alpha-Fe2O3 systems are characterized by a high purity and hierarchical morphologies consisting of nanopyramids/organized dendrites, offering a high contact area with the electrolyte. PEC data reveal a dramatic response enhancement upon thermal treatment, related to a more efficient electron transfer. The reasons underlying such a phenomenon are elucidated and discussed by transient absorption spectroscopy (TAS) studies of photogenerated charge carrier kinetics, investigated on different time scales for the first time on PE-CVD Fe2O3 nanostructures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000353931300037 Publication Date 2015-04-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1944-8244;1944-8252; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.504 Times cited 51 Open Access  
  Notes 246791 Countatoms; Fwo Approved Most recent IF: 7.504; 2015 IF: 6.723  
  Call Number c:irua:126059 Serial 3836  
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Author Iyikanat, F.; Sahin, H.; Senger, R.T.; Peeters, F.M. doi  openurl
  Title Vacancy formation and oxidation characteristics of single layer TiS3 Type A1 Journal article
  Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 119 Issue 119 Pages 10709-10715  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The structural, electronic, and magnetic properties of pristine, defective, and oxidized monolayer TiS3 are investigated using first-principles calculations in the framework of density functional theory. We found that a single layer of TiS3 is a direct band gap semiconductor, and the bonding nature of the crystal is fundamentally different from other transition metal chalcogenides. The negatively charged surfaces of single layer TiS3 makes this crystal a promising material for lubrication applications. The formation energies of possible vacancies, i.e. S, Ti, TiS, and double S, are investigated via total energy optimization calculations. We found that the formation of a single S vacancy was the most likely one among the considered vacancy types. While a single S vacancy results in a nonmagnetic, semiconducting character with an enhanced band gap, other vacancy types induce metallic behavior with spin polarization of 0.3-0.8 mu(B). The reactivity of pristine and defective TiS3 crystals against oxidation was investigated using conjugate gradient calculations where we considered the interaction with atomic O, O-2, and O-3. While O-2 has the lowest binding energy with 0.05-0.07 eV, O-3 forms strong bonds stable even at moderate temperatures. The strong interaction (3.9-4.0 eV) between atomic O and TiS3 results in dissociative adsorption of some O-containing molecules. In addition, the presence of S-vacancies enhances the reactivity of the surface with atomic O, whereas it had a negative effect on the reactivity with O-2 and O-3 molecules.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000354912200063 Publication Date 2015-04-28  
  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 51 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie Fellowship. RI., H.S., and R.T.S. acknowledge the support from TUBITAK through project 114F397. ; Approved Most recent IF: 4.536; 2015 IF: 4.772  
  Call Number c:irua:126410 Serial 3829  
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Author Nicholls, D.; Li, R.R.; Ware, B.; Pansegrau, C.; Çakir, D.; Hoffmann, M.R.; Oncel, N. doi  openurl
  Title Scanning tunneling microscopy and density functional theory study on zinc(II)-phthalocyanine tetrasulfonic acid on bilayer epitaxial graphene on silicon carbide(0001) Type A1 Journal article
  Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 119 Issue 119 Pages 9845-9850  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Zinc(II)-phthalocyanine tetrasulfonic acid (Zn-PcS) molecules physisorbed on bilayer epitaxial graphene on silicon carbide (SiC(0001)) were studied by using scanning tunneling microscopy/spectroscopy (STM/STS) and density functional theory (DFT). Two different methods were used to deposit Zn-PcS molecules and regardless of the method being used, the surface coverage stayed very low indicating the weakness of surface-molecule interaction. STS measurements revealed that derivative of tunneling current with respect to voltage (dI/dV) measured on Zn-PcS molecules did not exhibit the characteristic dip observed on dI/dV curves of pristine bilayer epitaxial graphene. DFT calculations show that the energy of the lowest unoccupied molecular orbital (LUMO) of the Zn-PcS molecule is below the Dirac point of graphene which enhances local density of states (LDOS). We attribute the disappearance of the dip in the dI/dV curves measured on the Zn-PcS/bilayer system to the LUMO of Zn-PcS. Charge density calculations along Zn-PcS/graphene interface reveal that there is a small charge transfer from graphene to the molecule. Calculated adsorption energy (3.13 eV) of the molecule is notably low and is consistent with the observed low surface coverage at room temperature.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000354339000020 Publication Date 2015-04-15  
  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 3 Open Access  
  Notes ; We gratefully acknowledge the NSF (Grant Nos.: DMR-1306101, EPS-814442, and EPS-1354366) for financial support. ; Approved Most recent IF: 4.536; 2015 IF: 4.772  
  Call Number c:irua:126370 Serial 2947  
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Author Kang, J.; Sahin, H.; Peeters, F.M. doi  openurl
  Title Tuning carrier confinement in the MoS2/WS2 lateral heterostructure Type A1 Journal article
  Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 119 Issue 119 Pages 9580-9586  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract To determine and control the spatial confinement of charge carriers is of importance for nanoscale optoelectronic device applications. Using first-principles calculations, we investigate the tunability of band alignment and Charge localization in lateral and combined lateral vertical heterostructures of MoS2 and WS2. First, we Show that a type-II to type-I band alignment transition takes place when tensile strain is applied on the WS2 region. This band alignment transition is a result of the different response of the band edge states with strain and is caused by their different wave function characters. Then we show that the presence of the grain boundary introduces localized in-gap states. The boundary at the armchair interface significantly modifies the charge distribution of the valence band maximum (VBM) state, whereas in a heterostructure with tilt grain domains both conducation band maximum (CBM) and VBM are found to be localized around the grain boundary. We also found that the thickness of the constituents in a lateral heterostructure also determines how the electrons and holes are confined. Creating combined lateral vertical heterostructures of MOS2/WS2 provides another way cif tuning the charge confinement. These results provide possible ways to tune the carrier confinement in MoS2/WS2 heterostructures, which are interesting for its practical: applications in the future.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000353930700066 Publication Date 2015-04-07  
  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 73 Open Access  
  Notes ; This work was supported by the Methusalem program of the Flemish government. H.S. is supported by a FWO Pegasus Marie Curie-long Fellowship and J.K. by a FWO Pegasus Marie Curie-short Fellowship. ; Approved Most recent IF: 4.536; 2015 IF: 4.772  
  Call Number c:irua:126381 Serial 3747  
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