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Author Wang, C.; Xin, X.; Shu, M.; Huang, S.; Zhang, Y.; Li, X. pdf  doi
openurl 
  Title Scalable synthesis of one-dimensional Na2Li2Ti6O14 nanofibers as ultrahigh rate capability anodes for lithium-ion batteries Type A1 Journal article
  Year 2019 Publication Inorganic Chemistry Frontiers Abbreviated Journal Inorg Chem Front  
  Volume 6 Issue 3 Pages 646-653  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits. Therefore, titanium-based materials have attracted great attention due to their high stability. Here, Na2Li2Ti6O14 nanofibers as anode materials were prepared through a controlled electrospinning method. The Na2Li2Ti6O14 nanofibers presented superior electrochemical performance with high rate capability and long cycle life and can be regarded as a competitive anode candidate for advanced Li-ion batteries. One-dimensional (1D) Na2Li2Ti6O14 nanofibers are able to deliver a capacity of 128.5 mA h g(-1) at 0.5C, and demonstrate superior high-rate charge-discharge capability and cycling stability (the reversible charge capacity is 77.8 mA h g(-1) with a capacity retention of 99.45% at the rate of 10C after 800 cycles). The 1D structure is considered to contribute remarkably to increased rate capability and stability. This simple and scalable method indicates that the Na2Li2Ti6O14 nanofibers have a practical application potential for high performance lithium-ion batteries.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000461092500027 Publication Date 2018-11-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2052-1553 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.036 Times cited 3 Open Access Not_Open_Access  
  Notes ; The authors acknowledge financial support from the National Natural Science Foundation of China (21571110), Natural Science Foundation of Zhejiang Province (LY18B010003), and the Ningbo Key Innovation Team (2014B81005), and sponsorship by the K.C. Wong Magna Fund in Ningbo University. ; Approved Most recent IF: 4.036  
  Call Number UA @ admin @ c:irua:158566 Serial 5258  
Permanent link to this record
 

 
Author García-Sánchez, C.; Philips, D.A.; Gorlé, C. pdf  doi
openurl 
  Title Quantifying inflow uncertainties for CFD simulations of the flow in downtown Oklahoma City Type A1 Journal article
  Year 2014 Publication Building and environment Abbreviated Journal Build Environ  
  Volume 78 Issue Pages 118-129  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Computational Fluid Dynamics (CFD) methods are widely used to investigate wind flow and dispersion in urban environments. Validation with field experiments that represent the full complexity of the problem should be performed to assess the predictive capabilities of the computations. In this context it will be necessary to quantify the effect of uncertainties in simulations of the full-scale problem. The present study aims at quantifying the uncertainty related to the variability in the inflow boundary conditions for Reynolds-averaged Navier-Stokes (RANS) simulations of the flow in downtown Oklahoma City to address validation with the Joint Urban 2003 field measurements. Three uncertain inflow parameters were defined: the wind speed and wind direction at a reference height, and the aerodynamic roughness in the logarithmic velocity inlet profile. An ensemble of 729 RANS simulations were performed to determine the polynomial chaos expansion coefficients that define the response surfaces for the velocity magnitude and direction at 13 field measurement stations, and the results are compared to the experimental data. For the velocity magnitude the mean experimental velocity magnitude is encompassed within the 95% confidence interval for the magnitudes predicted by the Uncertainty Quantification study in all stations. For the velocity direction this holds in 11 out of 13 locations. The study demonstrates the significant potential of applying advanced uncertainty quantification methods to address validation with field measurements and to develop a more realistic approach to the definition of inflow boundary conditions in atmospheric CFD simulations. (C) 2014 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Oxford Editor  
  Language Wos 000338619700013 Publication Date 2014-05-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0360-1323; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.053 Times cited 29 Open Access  
  Notes Approved Most recent IF: 4.053; 2014 IF: 3.341  
  Call Number UA @ lucian @ c:irua:118632 Serial 2742  
Permanent link to this record
 

 
Author Barreca, D.; Gasparotto, A.; Maccato, C.; Tondello, E.; Lebedev, O.I.; Van Tendeloo, G. pdf  doi
openurl 
  Title CVD of copper oxides from a \beta-diketonate diamine precursor: tailoring the nano-organization Type A1 Journal article
  Year 2009 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 9 Issue 5 Pages 2470-2480  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A copper(II) hexafluoroacetylacetonate (1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, hfa) adduct with N,N,N¡ä,N¡ä-tetramethylethylenediamine (TMEDA) [Cu(hfa)2¡¤TMEDA] is used for the first time as precursor for the chemical vapor deposition (CVD) of copper oxide nanosystems. The syntheses are carried out under both O2 and O2+H2O reaction atmospheres on Si(100) substrates, at temperatures ranging between 250 and 550 ¡ãC. Subsequently, the interrelations between the preparative conditions and the system composition, nanostructure, and morphology are elucidated by means of complementary analytical techniques [Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron and X-ray excited auger electron spectroscopies (XPS and XE-AES), glancing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM)]. The obtained data revealed a gradual transformation from Cu2O, to Cu2O + CuO, to CuO nanosystems upon increasing the deposition temperature from 250 to 550 ¡ãC under both growth atmospheres. Such a phenomenon was accompanied by a progressive morphological evolution from continuous films to 1D hyperbranched nanostructures. Water vapor introduction in the deposition environment enabled to lower the deposition temperature and resulted in a higher aggregate interconnection, attributed to a higher density of nucleation centers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000265892200066 Publication Date 2009-05-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 60 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 4.055; 2009 IF: 4.162  
  Call Number UA @ lucian @ c:irua:77053 Serial 597  
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Author Neira, I.S.; Kolen'ko, Y.V.; Lebedev, O.I.; Van Tendeloo, G.; Gupta, H.S.; Guitián, F.; Yoshimura, M. pdf  doi
openurl 
  Title An effective morphology control of hydroxyapatite crystals via hydrothermal synthesis Type A1 Journal article
  Year 2009 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 9 Issue 1 Pages 466-474  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A facile urea-assisted hydrothermal synthesis and systematic characterization of hydroxyapatite (HA) with calcium nitrate tetrahydrate and diammonium hydrogen phosphate as precursors are reported. The advantage of the proposed technique over previously reported synthetic approaches is the simple but precise control of the HA crystals morphology, which is achieved by employing an intensive, stepwise, and slow thermal decomposition of urea as well as varying initial concentrations of starting reagents. Whereas the plate-, hexagonal prism- and needle-like HA particles preferentially growth along the c-axis, the smaller and fine-plate-like HA crystals demonstrate crystal growth along the (102) and (211) directions, uncommon for HA. Furthermore, it was established that the hydrothermally derived powdered products are phase-pure HA containing CO32− anions in the crystal lattice, that is, AB-type carbonated hydroxyapatite. Transmission electron microscopy (TEM) and electron diffraction (ED) of selected samples reveal that the as-prepared HA crystals are single-crystalline and exhibit a nearly defect-free microstructure. The hardness and elastic modulus of the hexagonal prism-like HA crystals have been investigated on a nanoscale using the nanoindentation technique; the observed trends are discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000262332700073 Publication Date 2008-11-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 183 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 4.055; 2009 IF: 4.162  
  Call Number UA @ lucian @ c:irua:75740 Serial 853  
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Author Bekermann, D.; Gasparotto, A.; Barreca, D.; Bovo, L.; Devi, A.; Fischer, R.A.; Lebedev, O.I.; Maccato, C.; Tondello, E.; Van Tendeloo, G. pdf  doi
openurl 
  Title Highly oriented ZnO nanorod arrays by a novel plasma chemical vapor deposition process Type A1 Journal article
  Year 2010 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 10 Issue 4 Pages 2011-2018  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Strongly c-axis oriented ZnO nanorod arrays were grown on Si(100) by plasma enhanced-chemical vapor deposition (PE-CVD) starting from two volatile bis(ketoiminato) zinc(II) compounds Zn[(R′)NC(CH3)═C(H)C(CH3)═O]2, with R′ = -(CH2)xOCH3 (x = 2, 3). A systematic investigation of process parameters enabled us to obtain the selective formation of ZnO nanorods with tailored features, and provided an important insight into their growth mechanism. The morphology, structure, and composition of the synthesized ZnO nanosystems were thoroughly analyzed by field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDXS), glancing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Photoluminescence (PL) measurements were carried out to gain information on the optical properties. Specifically, one-dimensional (1D) ZnO architectures could be grown on Si(100) substrates at temperatures as low as 200−300 °C and radio frequency (RF)-power values of 20 W, provided that a sufficiently high mass supply to the growth surface was maintained. To the best of our knowledge, the present work reports the mildest preparation conditions ever appeared in the literature for the PE-CVD of ZnO nanorods, a key result in view of potential large-scale technological applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000276234500080 Publication Date 2010-03-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 75 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 4.055; 2010 IF: 4.390  
  Call Number UA @ lucian @ c:irua:82311 Serial 1472  
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Author Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L. pdf  doi
openurl 
  Title Insight into the growth of multiple branched MnOOH nanorods Type A1 Journal article
  Year 2010 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 10 Issue 7 Pages 2969-2976  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000279422700027 Publication Date 2010-06-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 41 Open Access  
  Notes Fwo; Esteem 026019 Approved Most recent IF: 4.055; 2010 IF: 4.390  
  Call Number UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 Serial 1672  
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Author Hoang, D.-Q.; Pobedinskas, P.; Nicley, S.S.; Turner, S.; Janssens, S.D.; Van Bael, M.K.; D'Haen, J.; Haenen, K. url  doi
openurl 
  Title Elucidation of the Growth Mechanism of Sputtered 2D Hexagonal Boron Nitride Nanowalls Type A1 Journal article
  Year 2016 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 16 Issue 7 Pages 3699-3708  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Hexagonal boron nitride nanowall thin films were deposited on Si(100) substrates using a Ar(51%)/N-2(44%)/H-2(5%) gas mixture by unbalanced radio frequency sputtering. The effects of various target-to-substrate distances, substrate temperatures, and substrate tilting angles were investigated. When the substrate is close to the target, hydrogen etching plays a significant role in the film growth, while the effect is negligible for films deposited at a farther distance. The relative quantity of defects was measured by a non-destructive infrared spectroscopy technique that characterized the hydrogen incorporation at dangling nitrogen bonds at defect sites in the deposited films. Despite the films deposited at different substrate tilting angles, the nanowalls of those films were found to consistently grow vertical to the substrate surface, independent of the tilting angle. This implies that chemical processes, rather than physical ones, govern the growth of the nanowalls. The results also reveal that the degree of nanowall crystallization is tunable by varying the growth parameters. Finally, evidence of hydrogen desorption during vacuum annealing is given based on measurements of infrared stretching (E-1u) and bending (A(2u)) modes of the optical phonons, and the H-N vibration mode.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000379456700020 Publication Date 2016-05-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 8 Open Access  
  Notes Approved Most recent IF: 4.055  
  Call Number UA @ lucian @ c:irua:144690 Serial 4652  
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Author Drijkoningen, S.; Pobedinskas, P.; Korneychuk, S.; Momot, A.; Balasubramaniam, Y.; Van Bael, M.K.; Turner, S.; Verbeeck, J.; Nesladekt, M.; Haenen, K. doi  openurl
  Title On the Origin of Diamond Plates Deposited at Low Temperature Type A1 Journal article
  Year 2017 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume 17 Issue 8 Pages 4306-4314  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crucial requirement for diamond growth at low temperatures, enabling a wide range of new applications, is a high plasma density at a low gas pressure, which leads to a low thermal load onto sensitive substrate materials. While these conditions are not within reach for resonance cavity plasma systems, linear antenna microwave delivery systems allow the deposition of high quality diamond films at temperatures around 400 degrees C and at pressures below 1 mbar. In this work the codeposition of high quality plates and octahedral diamond grains in nanocrystalline films is reported. In contrast to previous reports claiming the need for high temperatures (T >= 850 degrees C), low temperatures (320 degrees C <= T <= 410 degrees C) were sufficient to deposit diamond plate structures. Cross-sectional high resolution transmission electron microscopy studies show that these plates are faulty cubic diamond terminated by large {111} surface facets with very little sp(2) bonded carbon in the grain boundaries. Raman and electron energy loss spectroscopy studies confirm a high diamond quality, above 93% sp(3) carbon content. Three potential mechanisms, that can account for the initial development of the observed plates rich with stacking faults, and are based on the presence of impurities, are proposed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000407089600031 Publication Date 2017-06-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 23 Open Access Not_Open_Access  
  Notes ; The Research Foundation – Flanders (FWO) is gratefully acknowledged for financial support in the form of the Postdoctoral Fellowships of P.P. and S.T., contract G.0044.13N “Charge ordering” (S.K., J.V.), the Methusalem “Nano” network, and the Hercules-linear antenna and Raman equipment. ; Approved Most recent IF: 4.055  
  Call Number UA @ lucian @ c:irua:145735UA @ admin @ c:irua:145735 Serial 4746  
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Author Barreca, D.; Carraro, G.; Maccato, C.; Altantzis, T.; Kaunisto, K.; Gasparotto, A. url  doi
openurl 
  Title Controlled Growth of Supported ZnO Inverted Nanopyramids with Downward Pointing Tips Type A1 Journal article
  Year 2018 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des  
  Volume Issue Pages acs.cgd.8b00198  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High purity porous ZnO nanopyramids with controllable properties are grown on their tips on

Si(100) substrates by means of a catalyst-free vapor phase deposition route in a wet oxygen

reaction environment. The system degree of preferential [001] orientation, as well as

nanopyramid size, geometrical shape and density distribution, can be finely tuned by varying the

growth temperature between 300 and 400°C, whereas higher temperatures lead to more compact

systems with a three-dimensional (3D) morphology. A growth mechanism of the obtained ZnO

nanostructures based on a self-catalytic vapor-solid (VS) mode is proposed, in order to explain

the evolution of nanostructure morphologies as a function of the adopted process conditions. The

results obtained by a thorough chemico-physical characterization enable to get an improved

control over the properties of ZnO nanopyramids grown by this technique. Taken together, they

are of noticeable importance not only for fundamental research on ZnO nanomaterials with

controlled nano-organization, but also to tailor ZnO functionalities in view of various potential

applications.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000429508200073 Publication Date 2018-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-7483 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.055 Times cited 6 Open Access OpenAccess  
  Notes This work has been supported by Padova University ex-60% 2015–2017, P-DiSC #03BIRD2016-UNIPD projects and ACTION post-doc fellowship. T. A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO, Belgium). Thanks are also due to Dr. Rosa Calabrese (Department of Chemical Sciences, Padova University, Italy) and to Dr. T.-P. Ruoko (Department of Chemistry and Bioengineering, Tampere University of Technology, Finland) for skilful technical support. Approved Most recent IF: 4.055  
  Call Number EMAT @ emat @c:irua:149514 Serial 4904  
Permanent link to this record
 

 
Author Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. pdf  doi
openurl 
  Title Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations Type A1 Journal article
  Year 2016 Publication Dental Materials Abbreviated Journal Dent Mater  
  Volume 32 Issue 32 Pages e327-e337  
  Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);  
  Abstract OBJECTIVE: The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. METHODS: Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n=6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n=10), single edge V-notched beam (SEVNB) fracture toughness (n=8) and Vickers hardness (n=10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n=3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha=0.05). RESULTS: Lowering the alumina content below 0.25wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. SIGNIFICANCE: Three different approaches were compared to improve the translucency of 3Y-TZP ceramics.  
  Address KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000389516400003 Publication Date 2016-10-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0109-5641 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.07 Times cited Open Access  
  Notes The authors acknowledge the Research Fund of KU Leu- ven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post- doctoral fellowship (PDM/15/153). We thank M. Peumans for the translucency measurements. Approved Most recent IF: 4.07  
  Call Number EMAT @ emat @ c:irua:136821 Serial 4313  
Permanent link to this record
 

 
Author Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. pdf  doi
openurl 
  Title Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations Type A1 Journal article
  Year 2016 Publication Dental materials Abbreviated Journal Dent Mater  
  Volume 32 Issue 12 Pages E327-E337  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Objective. The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. Methods. Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n = 6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n = 10), single edge V-notched beam (SEVNB) fracture toughness (n = 8) and Vickers hardness (n = 10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n = 3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha = 0.05). Results. Lowering the alumina content below 0.25 wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5 mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2 mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. Significance. Three different approaches were compared to improve the translucency of 3YTZP ceramics. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Copenhagen Editor  
  Language Wos 000389516400003 Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0109-5641 ISBN Additional Links UA library record; WoS full record  
  Impact Factor (up) 4.07 Times cited 47 Open Access  
  Notes Approved Most recent IF: 4.07  
  Call Number UA @ lucian @ c:irua:140246 Serial 4447  
Permanent link to this record
 

 
Author Zhao, L.; Ding, L.; Soete, J.; Idrissi, H.; Kerckhofs, G.; Simar, A. pdf  url
doi  openurl
  Title Fostering crack deviation via local internal stresses in Al/NiTi composites and its correlation with fracture toughness Type A1 Journal article
  Year 2019 Publication Composites: part A: applied science and manufacturing Abbreviated Journal Compos Part A-Appl S  
  Volume 126 Issue 126 Pages 105617  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In the framework of metal matrix composites, a research gap exists regarding tailoring damage mechanisms. The present work aims at developing an Al/NiTi composite incorporating internal stresses in the vicinity of reinforcements. The composite is manufactured by friction stir processing which allows a homogenous NiTi distribution and a good Al/NiTi interface bonding. The internal stresses are introduced via shape memory effect of the embedded NiTi particles. The induced internal strain field is confirmed by digital image correlation and the corresponding stress field is evaluated by finite element simulation. It is found that the damage mechanism is modified in the presence of internal stresses. The consequent enhancement of fracture toughness arises by the fact that the internal stresses foster discrete damages shifted from the fracture ligament line. These damages release the stress concentration at the main crack tip and lead to a deviated crack path when coalescing to accommodate fracture propagation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000489350600025 Publication Date 2019-09-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-835x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.075 Times cited Open Access  
  Notes ; This research work has been exclusively supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no 716678). The X-ray computed,tomography facilities of the Department of Materials Engineering of the KU Leuven are financed by the Hercules Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). The authors acknowledge Professor F. Delannay from UCLouvain for fruitful discussions. ; Approved Most recent IF: 4.075  
  Call Number UA @ admin @ c:irua:163706 Serial 5387  
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Author Wei, H.; Hu, Z.-Y.; Xiao, Y.-X.; Tian, G.; Ying, J.; Van Tendeloo, G.; Janiak, C.; Yang, X.-Y.; Su, B.-L. pdf  doi
openurl 
  Title Control of the interfacial wettability to synthesize highly dispersed PtPd nanocrystals for efficient oxygen reduction reaction Type A1 Journal article
  Year 2018 Publication Chemistry: an Asian journal Abbreviated Journal Chem-Asian J  
  Volume 13 Issue 9 Pages 1119-1123  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Highly dispersed PtPd bimetallic nanocrystals with enhanced catalytic activity and stability were prepared by adjusting the interfacial wettability of the reaction solution on a commercial carbon support. This approach holds great promise for the development of high-performance and low-cost catalysts for practical applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000431625200006 Publication Date 2018-03-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1861-4728; 1861-471x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.083 Times cited 3 Open Access Not_Open_Access  
  Notes ; This work supported by National Key R&D Program of China (2017YFC1103800), PCSIRT (IRT15R52), NSFC (U1663225, U1662134, 51472190, 51611530672, 21711530705, 51503166), ISTCP (2015DFE52870), HPNSF (2016CFA033, 2017CFB487), and Open Project Program of State Key Laboratory of Petroleum Pollution Control (Grant No. PPC2016007), CNPC Research Institute of Safety and Environmental Technology, SKLPPC. ; Approved Most recent IF: 4.083  
  Call Number UA @ lucian @ c:irua:151525 Serial 5018  
Permanent link to this record
 

 
Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D.; Volety, K.; Huyberechts, G.; Paul, J. pdf  doi
openurl 
  Title High throughput first-principles calculations of bixbyite oxides for TCO applications Type A1 Journal article
  Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 16 Issue 33 Pages 17724-17733  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We present a high-throughput computing scheme based on density functional theory (DFT) to generate a class of oxides and screen them with the aim of identifying those that might be electronically appropriate for transparent conducting oxide (TCO) applications. The screening criteria used are a minimum band gap to ensure sufficient transparency, a band edge alignment consistent with easy n- or p-type dopability, and a minimum thermodynamic phase stability to be experimentally synthesizable. Following this scheme we screened 23 binary and 1518 ternary bixbyite oxides in order to identify promising candidates, which can then be a subject of an in-depth study. The results for the known TCOs are in good agreement with the reported data in the literature. We suggest a list of several new potential TCOs, including both n- and p-type compounds.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000341064800041 Publication Date 2014-07-07  
  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 (up) 4.123 Times cited 23 Open Access  
  Notes ; We gratefully acknowledge financial support from the IWT-Vlaanderen through the ISIMADE project (IWT-n 080023), the FWO-Vlaanderen through project G.0150.13 and a GOA fund from the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation and the Flemish Government (EWI Department). ; Approved Most recent IF: 4.123; 2014 IF: 4.493  
  Call Number UA @ lucian @ c:irua:118263 Serial 1469  
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Author Ahenach, J.; Cool, P.; Vansant, E.F.; Lebedev, O.; van Landuyt, J. doi  openurl
  Title Influence of water on the pillaring of montmorillonite with aminopropyltriethoxysilane Type A1 Journal article
  Year 1999 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 1 Issue Pages 3703-3708  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000081765300046 Publication Date 2002-07-26  
  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 (up) 4.123 Times cited 10 Open Access  
  Notes Approved Most recent IF: 4.123; 1999 IF: NA  
  Call Number UA @ lucian @ c:irua:28250 Serial 1660  
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Author Aerts, A.; Follens, L.R.A.; Biermans, E.; Bals, S.; Van Tendeloo, G.; Loppinet, B.; Kirschhock, C.E.A.; Martens, J.A. pdf  doi
openurl 
  Title Modelling of synchrotron SAXS patterns of silicalite-1 zeolite during crystallization Type A1 Journal article
  Year 2011 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 13 Issue 10 Pages 4318-4325  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Synchrotron small angle X-ray scattering (SAXS) was used to characterize silicalite-1 zeolite crystallization from TEOS/TPAOH/water clear sol. SAXS patterns were recorded over a broad range of length scales, enabling the simultaneous monitoring of nanoparticles and crystals occurring at various stages of the synthesis. A simple two-population model accurately described the patterns. Nanoparticles were modeled by polydisperse coreshell spheres and crystals by monodisperse oblate ellipsoids. These models were consistent with TEM images. The SAXS results, in conjunction with in situ light scattering, showed that nucleation of crystals occurred in a short period of time. Crystals were uniform in size and shape and became increasingly anisotropic during growth. In the presence of nanoparticles, crystal growth was fast. During crystal growth, the number of nanoparticles decreased gradually but their size was constant. These observations suggested that the nanoparticles were growth units in an aggregative crystal growth mechanism. Crystals grown in the presence of nanoparticles developed a faceted habit and intergrowths. In the final stages of growth, nanoparticles were depleted. Concurrently, the crystal growth rate decreased significantly.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000287584700017 Publication Date 2011-01-24  
  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 (up) 4.123 Times cited 22 Open Access  
  Notes Fwo; Iap; Esteem 026019 Approved Most recent IF: 4.123; 2011 IF: 3.573  
  Call Number UA @ lucian @ c:irua:87602 Serial 2155  
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Author Bekaert, J.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title Native point defects in CuIn1-xGaxSe2 : hybrid density functional calculations predict the origin of p- and n-type conductivity Type A1 Journal article
  Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 16 Issue 40 Pages 22299-22308  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We have performed a first-principles study of the p- and n-type conductivity in CuIn1−xGaxSe2 due to native point defects, based on the HSE06 hybrid functional. Band alignment shows that the band gap becomes larger with x due to the increasing conduction band minimum, rendering it hard to establish n-type conductivity in CuGaSe2. From the defect formation energies, we find that In/GaCu is a shallow donor, while VCu, VIn/Ga and CuIn/Ga act as shallow acceptors. Using the total charge neutrality of ionized defects and intrinsic charge carriers to determine the Fermi level, we show that under In-rich growth conditions InCu causes strongly n-type conductivity in CuInSe2. Under increasingly In-poor growth conditions, the conductivity type in CuInSe2 alters to p-type and compensation of the acceptors by InCu reduces, as also observed in photoluminescence experiments. In CuGaSe2, the native acceptors pin the Fermi level far away from the conduction band minimum, thus inhibiting n-type conductivity. On the other hand, CuGaSe2 shows strong p-type conductivity under a wide range of Ga-poor growth conditions. Maximal p-type conductivity in CuIn1−xGaxSe2 is reached under In/Ga-poor growth conditions, in agreement with charge concentration measurements on samples with In/Ga-poor stoichiometry, and is primarily due to the dominant acceptor CuIn/Ga.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000343072800042 Publication Date 2014-09-05  
  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 (up) 4.123 Times cited 43 Open Access  
  Notes ; We gratefully acknowledge financial support from the science fund FWO-Flanders through project G.0150.13. The first-principles calculations have been carried out on the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Centre (VSC), supported financially by the Hercules foundation and the Flemish Government (EWI Department). We also like to thank Prof. S. Siebentritt of the University of Luxembourg for a presentation of her work on GIGS during a visit to our research group and for helpful discussions of our results. ; Approved Most recent IF: 4.123; 2014 IF: 4.493  
  Call Number UA @ lucian @ c:irua:120465 Serial 2284  
Permanent link to this record
 

 
Author Amini, M.N.; Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B. pdf  doi
openurl 
  Title The origin of p-type conductivity in ZnM2O4 (M = Co, Rh, Ir) spinels Type A1 Journal article
  Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 16 Issue 6 Pages 2588-2596  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract ZnM2O4 (M = Co, Rh, Ir) spinels are considered as a class of potential p-type transparent conducting oxides (TCOs). We report the formation energy of acceptor-like defects using first principles calculations with an advanced hybrid exchange-correlation functional (HSE06) within density functional theory (DFT). Due to the discrepancies between the theoretically obtained band gaps with this hybrid functional and the – scattered – experimental results, we also perform GW calculations to support the validity of the description of these spinels with the HSE06 functional. The considered defects are the cation vacancy and antisite defects, which are supposed to be the leading source of disorder in the spinel structures. We also discuss the band alignments in these spinels. The calculated formation energies indicate that the antisite defects ZnM (Zn replacing M, M = Co, Rh, Ir) and VZn act as shallow acceptors in ZnCo2O4, ZnRh2O4 and ZnIr2O4, which explains the experimentally observed p-type conductivity in those systems. Moreover, our systematic study indicates that the ZnIr antisite defect has the lowest formation energy in the group and it corroborates the highest p-type conductivity reported for ZnIr2O4 among the group of ZnM2O4 spinels. To gain further insight into factors affecting the p-type conductivity, we have also investigated the formation of localized small polarons by calculating the self-trapping energy of the holes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000329926700040 Publication Date 2013-12-03  
  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 (up) 4.123 Times cited 47 Open Access  
  Notes Fwo; Goa; Hercules Approved Most recent IF: 4.123; 2014 IF: 4.493  
  Call Number UA @ lucian @ c:irua:114829 Serial 2525  
Permanent link to this record
 

 
Author Sliem, M.A.; Turner, S.; Heeskens, D.; Kalidindi, S.B.; Van Tendeloo, G.; Muhler, M.; Fischer, R.A. pdf  doi
openurl 
  Title Preparation, microstructure characterization and catalytic performance of Cu/ZnO and ZnO/Cu composite nanoparticles for liquid phase methanol synthesis Type A1 Journal article
  Year 2012 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 14 Issue 22 Pages 8170-8178  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Stearate@Cu/ZnO nanocomposite particles with molar ratios of ZnO ∶ Cu = 2 and 5 are synthesized by reduction of the metalorganic Cu precursor [Cu{(OCH(CH3)CH2N(CH3)2)}2] in the presence of stearate@ZnO nanoparticles. In the case of ZnO ∶ Cu = 5, high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) combined with electron-energy-loss-spectroscopy (EELS) as well as attenuated total reflection Fourier transform infrared (ATR-IR) spectroscopy are used to localize the small amount of Cu deposited on the surface of 35 nm sized stearate@ZnO particles. For ZnO ∶ Cu = 2, the microstructure of the nanocomposites after catalytic activity testing is characterized by HAADF-STEM techniques. This reveals the construction of large Cu nanoparticles (2050 nm) decorated by small ZnO nanoparticles (35 nm). The catalytic activity of both composites for the synthesis of methanol from syn gas is evaluated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000304102200033 Publication Date 2012-04-16  
  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 (up) 4.123 Times cited 16 Open Access  
  Notes Fwo Approved Most recent IF: 4.123; 2012 IF: 3.829  
  Call Number UA @ lucian @ c:irua:98377 Serial 2702  
Permanent link to this record
 

 
Author Piedigrosso, P.; Konya, Z.; Colomer, J.-F.; Fonseca, A.; Van Tendeloo, G.; Nagy, J.B. pdf  url
doi  openurl
  Title Production of differently shaped multi-wall carbon nanotubes using various cobalt supported catalysts Type A1 Journal article
  Year 2000 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 2 Issue 1 Pages 163-170  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Catalytic synthesis and transmission electron microscopy (TEM) of multi-wall carbon nanotubes are presented. Silica, zeolite and alumina supported cobalt catalysts were prepared by different methods (impregnation and ion-adsorption precipitation) and were used to produce nanotubes. The synthesis was carried out in a fixed bed flow reactor and the process was optimized in order to produce carbon nanotubes on a gram scale. The influence of various parameters such as the method of catalyst preparation, the nature of the support, cobalt concentration and reaction conditions on the formation of nanotubes was investigated. The carbon deposits were measured and the quality of nanotubes was determined by low and high resolution TEM. Multi-wall straight and coiled nanotubes were found to be fairly regular with an average inner (outer) diameter of 4-7 nm (8-23 nm) and with lengths up to 0.1 mm.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000084333800025 Publication Date 2002-07-26  
  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 (up) 4.123 Times cited 53 Open Access  
  Notes Approved Most recent IF: 4.123; 2000 IF: 1.653  
  Call Number UA @ lucian @ c:irua:102889 Serial 2723  
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Author Hermans, I.; Breynaert, E.; Poelman, H.; de Gryse, R.; Liang, D.; Van Tendeloo, G.; Maes, A.; Peeters, J.; Jacobs, P. doi  openurl
  Title Silica-supported chromium oxide: colloids as building blocks Type A1 Journal article
  Year 2007 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 9 Issue 39 Pages 5382-5386  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000249925500022 Publication Date 2007-10-03  
  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 (up) 4.123 Times cited 8 Open Access  
  Notes Approved Most recent IF: 4.123; 2007 IF: 3.343  
  Call Number UA @ lucian @ c:irua:66752 Serial 3000  
Permanent link to this record
 

 
Author Huang, W.; Zhang, X.-B.; Tu, J.; Kong, F.; Ning, Y.; Xu, J.; Van Tendeloo, G. pdf  doi
openurl 
  Title Synthesis and characterization of graphite nanofibers deposited on nickel foams Type A1 Journal article
  Year 2002 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 4 Issue 21 Pages 5325-5329  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Nickel foams were used as catalysts to dissociate acetylene and deposit carbon atoms. Graphite nanofibers with distinct structures were developed at 550degreesC with nickel foams pretreated with hydrogen. HREM observations showed that the graphite layers of the nanofibers were aligned at a certain angle to the fiber axis. It is suggested that hydrogen treatment and metal catalysts have a tremendous impact on the yields and microstructures of the graphite nanofibers. The growth mechanism of these fish-bone graphite nanofibers is also discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000178635300016 Publication Date 2002-10-17  
  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 (up) 4.123 Times cited 20 Open Access  
  Notes Approved Most recent IF: 4.123; 2002 IF: 1.838  
  Call Number UA @ lucian @ c:irua:94938 Serial 3411  
Permanent link to this record
 

 
Author Amini, M.N.; Saniz, R.; Lamoen, D.; Partoens, B. pdf  url
doi  openurl
  Title The role of the VZn-NO-H complex in the p-type conductivity in ZnO Type A1 Journal article
  Year 2015 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 17 Issue 17 Pages 5485-5489  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Past research efforts aiming at obtaining stable p-type ZnO have been based on complexes involving nitrogen doping. A recent experiment by (J. G. Reynolds et al., Appl. Phys. Lett., 2013, 102, 152114) demonstrated a significant ([similar]1018 cm−3) p-type behavior in N-doped ZnO films after appropriate annealing. The p-type conductivity was attributed to a VZnNOH shallow acceptor complex, formed by a Zn vacancy (VZn), N substituting O (NO), and H interstitial (Hi). We present here a first-principles hybrid functional study of this complex compared to the one without hydrogen. Our results confirm that the VZnNOH complex acts as an acceptor in ZnO. We find that H plays an important role, because it lowers the formation energy of the complex with respect to VZnNO, a complex known to exhibit (unstable) p-type behavior. However, this additional H atom also occupies the hole level at the origin of the shallow behavior of VZnNO, leaving only two states empty higher in the band gap and making the VZnNOH complex a deep acceptor. Therefore, we conclude that the cause of the observed p-type conductivity in experiment is not the presence of the VZnNOH complex, but probably the formation of the VZnNO complex during the annealing process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000349616400080 Publication Date 2015-01-20  
  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 (up) 4.123 Times cited 20 Open Access  
  Notes FWO G021614N; FWO G015013; FWO G018914N; GOA; Hercules Approved Most recent IF: 4.123; 2015 IF: 4.493  
  Call Number c:irua:123218 Serial 3592  
Permanent link to this record
 

 
Author Zeng, Y.I.; Menghini, M.; Li, D.Y.; Lin, S.S.; Ye, Z.Z.; Hadermann, J.; Moorkens, T.; Seo, J.W.; Locquet, J.-P.; van Haesendonck, C. doi  openurl
  Title Unexpected optical response of single ZnO nanowires probed using controllable electrical contacts Type A1 Journal article
  Year 2011 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 13 Issue 15 Pages 6931-6935  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Relying on combined electron-beam lithography and lift-off methods Au/Ti bilayer electrical contacts were attached to individual ZnO nanowires (NWs) that were grown by a vapor phase deposition method. Reliable Schottky-type as well as ohmic contacts were obtained depending on whether or not an ion milling process was used. The response of the ZnO NWs to ultraviolet light was found to be sensitive to the type of contacts. The intrinsic electronic properties of the ZnO NWs were studied in a field-effect transistor configuration. The transfer characteristics, including gate threshold voltage, hysteresis and operational mode, were demonstrated to unexpectedly respond to visible light. The origin of this effect could be accounted for by the presence of point defects in the ZnO NWs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000288951000019 Publication Date 2011-03-14  
  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 (up) 4.123 Times cited 7 Open Access  
  Notes Approved Most recent IF: 4.123; 2011 IF: 3.573  
  Call Number UA @ lucian @ c:irua:89378 Serial 3807  
Permanent link to this record
 

 
Author Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B. pdf  url
doi  openurl
  Title The role of hydrogen during Pt-Ga nanocatalyst formation Type A1 Journal article
  Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 3234-3243  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles.  
  Address Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000369506000106 Publication Date 2016-01-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 10 Open Access  
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. Approved Most recent IF: 4.123  
  Call Number c:irua:132315 Serial 4000  
Permanent link to this record
 

 
Author Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon Type A1 Journal article
  Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 20542-20549  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency.  
  Address EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000381428600058 Publication Date 2016-07-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 34 Open Access  
  Notes We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO FWOVlaanderen. Approved Most recent IF: 4.123  
  Call Number c:irua:135091 Serial 4112  
Permanent link to this record
 

 
Author Calizzi, M.; Venturi, F.; Ponthieu, M.; Cuevas, F.; Morandi, V.; Perkisas, T.; Bals, S.; Pasquini, L. pdf  doi
openurl 
  Title Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage Type A1 Journal article
  Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 141-148  
  Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)  
  Abstract Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 degrees C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000368755500014 Publication Date 2015-11-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 31 Open Access Not_Open_Access  
  Notes ; Part of this work was supported by the COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”. ; Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:131589 Serial 4184  
Permanent link to this record
 

 
Author Matsubara, M.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title Doping anatase TiO2with group V-b and VI-b transition metal atoms: a hybrid functional first-principles study Type A1 Journal article
  Year 2017 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 19 Issue 19 Pages 1945-1952  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We investigate the role of transition metal atoms of group V-b (V, Nb, Ta) and VI-b (Cr, Mo, W) as n- or p-type dopants in anatase TiO$2$ using thermodynamic

principles and density functional theory with the Heyd-Scuseria-Ernzerhof HSE06 hybrid functional. The HSE06 functional provides a realistic value for the band gap, which ensures a correct classification of dopants as shallow or deep donors or acceptors. Defect formation energies and thermodynamic transition levels are calculated taking into account the constraints imposed by the stability of TiO$
2$ and the solubility limit of the impurities.

Nb, Ta, W and Mo are identified as shallow donors. Although W provides two electrons, Nb and Ta show a considerable lower formation energy, in particular under O-poor conditions. Mo donates in principle one electron, but under specific conditions can turn into a double donor. V impurities are deep donors and Cr

shows up as an amphoteric defect, thereby acting as an electron trapping center in n-type TiO$_2$ especially under O-rich conditions. A comparison with the available experimental data yields excellent agreement.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000394426400027 Publication Date 2016-12-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 19 Open Access OpenAccess  
  Notes We gratefully acknowledge financial support from the IWTVlaanderenthrough projects G.0191.08 and G.0150.13, and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation. M. M. acknowledges financial support from the GOA project ‘‘XANES meets ELNES’’ of the University of Antwerp. Approved Most recent IF: 4.123  
  Call Number EMAT @ emat @ c:irua:140835 Serial 4421  
Permanent link to this record
 

 
Author Saniz, R.; Bekaert, J.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title Structural and electronic properties of defects at grain boundaries in CuInSe2 Type A1 Journal article
  Year 2017 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 19 Issue 19 Pages 14770-14780  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We report on a first-principles study of the structural and electronic properties of a Sigma3 (112) grain boundary model in CuInSe2. The study focuses on a coherent, stoichiometry preserving, cation–Se terminated grain boundary, addressing the properties of the grain boundary as such, as well as the effect

of well known defects in CuInSe2. We show that in spite of its apparent simplicity, such a grain boundary exhibits a very rich phenomenology, providing an explanation for several of the experimentally observed properties of grain boundaries in CuInSe2 thin films. In particular, we show that the combined effect of Cu vacancies and cation antisites can result in the observed Cu depletion with no In enrichment at the grain boundaries. Furthermore, Cu vacancies are unlikely to produce a hole barrier at the grain boundaries, but Na may indeed have such an effect. We find that Na-on-Cu defects will tend to form abundantly at

the grain boundaries, and can provide a mechanism for the carrier depletion and/or type inversion experimentally reported.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000403327200059 Publication Date 2017-05-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 12 Open Access OpenAccess  
  Notes We thank B. Schoeters for his assistance running the GBstudio software. We acknowledge the financial support of FWO-Vlaanderen through project G.0150.13. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by FWO-Vlaanderen and the Flemish Government-department EWI. Approved Most recent IF: 4.123  
  Call Number EMAT @ emat @ c:irua:143869 Serial 4577  
Permanent link to this record
 

 
Author Momot, A.; Amini, M.N.; Reekmans, G.; Lamoen, D.; Partoens, B.; Slocombe, D.R.; Elen, K.; Adriaensens, P.; Hardy, A.; Van Bael, M.K. pdf  url
doi  openurl
  Title A novel explanation for the increased conductivity in annealed Al-doped ZnO: an insight into migration of aluminum and displacement of zinc Type A1 Journal article
  Year 2017 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 19 Issue 40 Pages 27866-27877  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A combined experimental and first-principles study is performed to study the origin of conductivity in

ZnO:Al nanoparticles synthesized under controlled conditions via a reflux route using benzylamine as a

solvent. The experimental characterization of the samples by Raman, nuclear magnetic resonance (NMR)

and conductivity measurements indicates that upon annealing in nitrogen, the Al atoms at interstitial

positions migrate to the substitutional positions, creating at the same time Zn interstitials. We provide

evidence for the fact that the formed complex of AlZn and Zni corresponds to the origin of the Knight

shifted peak (KS) we observe in 27Al NMR. As far as we know, the role of this complex has not been

discussed in the literature to date. However, our first-principles calculations show that such a complex is

indeed energetically favoured over the isolated Al interstitial positions. In our calculations we also

address the charge state of the Al interstitials. Further, Zn interstitials can migrate from Al_Zn and possibly

also form Zn clusters, leading to the observed increased conductivity.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000413290500073 Publication Date 2017-10-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (up) 4.123 Times cited 26 Open Access OpenAccess  
  Notes We want to thank the Interuniversity Attraction Poles Programme (P7/05) initiated by the Belgian Science Policy Office (BELSPO) for the financial support. We also acknowledge the Research Foundation Flanders (FWO-Vlaanderen) for support via the MULTIMAR WOG project and under project No. G018914. The computational parts were carried out using the HPC infrastructure at the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the Hercules foundation and the Flemish Government (EWI Department). Approved Most recent IF: 4.123  
  Call Number EMAT @ emat @c:irua:146878 Serial 4760  
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