Home | << 1 >> |
![]() |
Records | |||||
---|---|---|---|---|---|
Author | Zhang, F.; Vanmeensel, K.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
Title ![]() |
3Y-TZP ceramics with improved hydrothermal degradation resistance and fracture toughness | Type | A1 Journal article | ||
Year | 2014 | Publication | Journal of the European Ceramic Society | Abbreviated Journal | J Eur Ceram Soc |
Volume | 34 | Issue | 10 | Pages | 2453-2463 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Different factors such as the way of incorporating the Y2O3 stabilizer, alumina addition and sintering temperature were assessed with the goal to improve the low temperature degradation (LTD) resistance of 3Y-TZP without compromising on the mechanical properties. The degradation of hydrothermally treated specimens was studied by X-ray diffraction, micro-Raman spectroscopy and scanning electron microscopy. Decreasing the sintering temperature decreased the LTD susceptibility of 3Y-TZPs but did not allow to obtain a LTD resistant 3Y-TZP with optimized mechanical properties. Alumina addition along with the use of Y2O3 stabilizer coated starting powder allowed to combine both an excellent toughness and LTD resistance, as compared to alumina-free and stabilizer co-precipitated powder based equivalents. Transmission electron microscopy revealed that the improved LTD resistance could be attributed to the segregation of Al3+ at the grain boundary and the heterogeneously distributed Y3+ stabilizer. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Barking | Editor | ||
Language | Wos | 000336352500033 | Publication Date | 2014-03-07 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0955-2219; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 48 | Open Access | |
Notes | Fwo G.0431.10n | Approved | Most recent IF: 3.411; 2014 IF: 2.947 | ||
Call Number | UA @ lucian @ c:irua:117065 c:irua:117065 | Serial | 11 | ||
Permanent link to this record | |||||
Author | Tunca, B.; Lapauw, T.; Callaert, C.; Hadermann, J.; Delville, R.; Caspi, E.'ad N.; Dahlqvist, M.; Rosen, J.; Marshal, A.; Pradeep, K.G.; Schneider, J.M.; Vleugels, J.; Lambrinou, K. | ||||
Title ![]() |
Compatibility of Zr₂AlC MAX phase-based ceramics with oxygen-poor, static liquid lead-bismuth eutectic | Type | A1 Journal article | ||
Year | 2020 | Publication | Corrosion Science | Abbreviated Journal | Corros Sci |
Volume | 171 | Issue | Pages | 108704-108719 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | This work investigates the compatibility of Zr2AlC MAX phase-based ceramics with liquid LBE, and proposes a mechanism to explain the observed local Zr2AlC/LBE interaction. The ceramics were exposed to oxygen-poor (C-O <= 2.2 x 10(-10) mass%), static liquid LBE at 500 degrees C for 1000 h. A new Zr-2(Al,Bi,Pb)C MAX phase solid solution formed in-situ in the LBE-affected Zr2AlC grains. Out-of-plane ordering was favorable in the new solid solution, whereby A-layers with high and low-Bi/Pb contents alternated in the crystal structure, in agreement with first-principles calculations. Bulk Zr-2(Al,Bi,Pb)C was synthesized by reactive hot pressing to study the crystal structure of the solid solution by neutron diffraction. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000537624600005 | Publication Date | 2020-04-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0010-938x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.3 | Times cited | 3 | Open Access | Not_Open_Access |
Notes | ; B.T. acknowledges the financial support of the SCK CEN Academy for Nuclear Science and Technology (Belgium). This research was partly funded by the European Atomic Energy Community's (Euratom) Seventh Framework Programme FP7/ 2007-2013 under Grant Agreement No. 604862 (FP7 MatISSE), the MYRRHA project (SCK CEN, Belgium), as well as by the Euratom research and training programme 2014-2018 under Grant Agreement No. 740415 (H2020 IL TROVATORE). The performed research falls within the framework of the EERA (European Energy Research Alliance) Joint Programme on Nuclear Materials (JPNM). The authors gratefully acknowledge the Hercules Foundation for Project AKUL/1319 (CombiS(T)EM)) and the Knut and Alice Wallenberg (KAW) foundation. The calculations were carried out using supercomputer resources provided by the Swedish National Infrastructure for Computing (SNIC) at the High Performance Computing Center North (HPC2N) and the PDC Center for High Performance Computing. E.N.C. thanks Offir Ozeri for his help in NPD data acquiring. ; | Approved | Most recent IF: 8.3; 2020 IF: 5.245 | ||
Call Number | UA @ admin @ c:irua:170157 | Serial | 6475 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Vanmeensel, K.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
Title ![]() |
Critical influence of alumina content on the low temperature degradation of 2-3 mol% yttria-stabilized TZP for dental restorations | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of the European Ceramic Society | Abbreviated Journal | J Eur Ceram Soc |
Volume | 35 | Issue | 35 | Pages | 741-750 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The influence of 0.25, 2 and 5 wt.% alumina addition on the mechanical properties and low temperature degradation (LTD) of 3, 2.5 and 2 mol% yttria-stabilized TZP ceramics was investigated. The amount of alumina addition was observed to have a crucial impact on the degradation of Y-TZP ceramics. Independent on the yttria stabilizer content, 0.25 wt.% alumina had a higher degradation retarding effect to Y-TZP ceramics than 2 and 5 wt.% of alumina addition, which had a comparable effect. The apparent activation energy for the degradation process was increased by adding alumina, but it was the same for 0.255 wt.% alumina doped 3Y-TZP ceramics. For Y-TZPs containing a small amount of alumina addition, only the segregated Al3+ at the grain boundaries of the zirconia grains was effective to retard the degradation of Y-TZPs. The secondary phase Al2O3 grains increased the degradation kinetics, which might be attributed to the residual stresses. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Barking | Editor | ||
Language | Wos | 000345201700032 | Publication Date | 2014-09-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0955-2219; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 37 | Open Access | |
Notes | Fwo G043110n | Approved | Most recent IF: 3.411; 2015 IF: 2.947 | ||
Call Number | c:irua:121328 | Serial | 544 | ||
Permanent link to this record | |||||
Author | Buffière, M.; Zaghi, A.E.; Lenaers, N.; Batuk, M.; Khelifi, S.; Drijkoningen, J.; Hamon, J.; Stesmans, A.; Kepa, J.; Afanas’ev, V.V.; Hadermann, J.; D’Haen, J.; Manca, J.; Vleugels, J.; Meuris, M.; Poortmans, J.; | ||||
Title ![]() |
Effect of binder content in Cu-In-Se precursor ink on the physical and electrical properties of printed CuInSe2 solar cells | Type | A1 Journal article | ||
Year | 2014 | Publication | The journal of physical chemistry: C : nanomaterials and interfaces | Abbreviated Journal | J Phys Chem C |
Volume | 118 | Issue | 47 | Pages | 27201-27209 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Printed chalcopyrite thin films have attracted considerable attention in recent years due to their potential in the high-throughput production of photovoltaic devices. To improve the homogeneity of printed CuInSe2 (CISe) layers, chemical additives such as binder can be added to the precursor ink. In this contribution, we investigate the influence of the dicyandiamide (DCDA) content, used as a binder in the precursor ink, on the physical and electrical properties of printed CISe solar cells. It is shown that the use of the binder leads to a dense absorber, composed of large CISe grains close to the surface, while the bulk of the layer consists of CISe crystallites embedded in a CuxS particle based matrix, resulting from the limited sintering of the precursor in this region. The expected additional carbon contamination of the CISe layer due to the addition of the binder appears to be limited, and the optical properties of the CISe layer are similar to the reference sample without additive. The electrical characterization of the corresponding CISe/CdS solar cells shows a degradation of the efficiency of the devices, due to a modification in the predominant recombination mechanisms and a limitation of the space charge region width when using the binder; both effects could be explained by the inhomogeneity of the bulk of the CISe absorber and high defect density at the CISe/CuxS-based matrix interface. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000345722400003 | Publication Date | 2014-11-06 | |
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 | 4 | Open Access | |
Notes | Approved | Most recent IF: 4.536; 2014 IF: 4.772 | |||
Call Number | UA @ lucian @ c:irua:121332 | Serial | 801 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Batuk, M.; Hadermann, J.; Manfredi, G.; Mariën, A.; Vanmeensel, K.; Inokoshi, M.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
Title ![]() |
Effect of cation dopant radius on the hydrothermal stability of tetragonal zirconia: Grain boundary segregation and oxygen vacancy annihilation | Type | A1 Journal article | ||
Year | 2016 | Publication | Acta materialia | Abbreviated Journal | Acta Mater |
Volume | 106 | Issue | 106 | Pages | 48-58 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The hydrothermal aging stability of 3Y-TZP-xM2O3 (M = La, Nd, Sc) was investigated as a function of 0.02–5 mol% M2O3 dopant content and correlated to the overall phase content, t-ZrO2 lattice parameters, grain size distribution, grain boundary chemistry and ionic conductivity. The increased aging stability with increasing Sc2O3 content and the optimum content of 0.4–0.6 mol% Nd2O3 or 0.2–0.4 mol% La2O3, resulting in the highest aging resistance, could be directly related to the constituent phases and the lattice parameters of the remaining tetragonal zirconia. At low M2O3 dopant contents ≤0.4 mol%, the different aging behavior of tetragonal zirconia was attributed to the defect structure of the zirconia grain boundary which was influenced by the dopant cation radius. It was observed that the grain boundary ionic resistivity and the aging resistance followed the same trend: La3+ > Nd3+ > Al3+ > Sc3+, proving that hydrothermal aging is driven by the diffusion of water-derived mobile species through the oxygen vacancies. Accordingly, we elucidated the underlying mechanism by which a larger trivalent cation segregating at the zirconia grain boundary resulted in a higher aging resistance. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000371650300006 | Publication Date | 2016-01-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1359-6454 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 5.301 | Times cited | 37 | Open Access | |
Notes | The authors acknowledge the Research Fund of KU Leuven 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). | Approved | Most recent IF: 5.301 | ||
Call Number | c:irua:132435 | Serial | 4076 | ||
Permanent link to this record | |||||
Author | Fang, P.a.; Gu, H.; Wang, P.l.; Van Landuyt, J.; Vleugels, J.; Van der Biest, O.; | ||||
Title ![]() |
Effect of powder coating on stabilizer distribution in CeO2-stabilized ZrO2 ceramics | Type | A1 Journal article | ||
Year | 2005 | Publication | Journal of the American Ceramic Society | Abbreviated Journal | J Am Ceram Soc |
Volume | 88 | Issue | 7 | Pages | 1929-1934 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The phase and microstructure relationship of 12 mol% CeO2-stabilized ZrO2 ceramics prepared from coated powder was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersed Xray spectroscopy (EDS). As compared with the sample prepared with co-precipitated method, which exhibited a similar grain size distribution, the EDS analysis revealed that the powder coating induced a wide distribution of CeO2 solubility, which decreases monotonically with the increase of grain size. This variation of stabilizer content from grain to grain rendered many large grains in the monoclinic phase. Stronger cerium segregation to grain boundaries was observed between large grains, which often form thin amorphous films there. The inhomogeneous; CeO2 distribution keeps more tetragonal ZrO2 grains close to the phase boundary to facilitate the transforming toughness. Addition of an Al2O3 precursor in coated powders effectively raises the overall CeO2 stabilizer content in the grains and preserves more transformable tetragonal phase in the microstructure, which further enhanced the fracture toughness. The dependence of CeO2 solubility on grain size may be explained in a simple coating-controlled diffusion and growth process that deserves further investigation. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Columbus, Ohio | Editor | ||
Language | Wos | 000230128100040 | Publication Date | 2005-06-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0002-7820;1551-2916; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.841 | Times cited | 11 | Open Access | |
Notes | Approved | Most recent IF: 2.841; 2005 IF: 1.586 | |||
Call Number | UA @ lucian @ c:irua:103156 | Serial | 830 | ||
Permanent link to this record | |||||
Author | E. Zaghi, A.; Buffière, M.; Koo, J.; Brammertz, G.; Batuk, M.; Verbist, C.; Hadermann, J.; Kim, W.K.; Meuris, M.; Poortmans, J.; Vleugels, J.; | ||||
Title ![]() |
Effect of selenium content of CuInSex alloy nanopowder precursors on recrystallization of printed CuInSe2 absorber layers during selenization heat treatment | Type | A1 Journal article | ||
Year | 2014 | Publication | Thin solid films : an international journal on the science and technology of thin and thick films | Abbreviated Journal | Thin Solid Films |
Volume | Issue | Pages | 1-7 | ||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Polycrystalline CuInSe2 semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe2 semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSex (x = 2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe2 phase during the selenization process was investigated. The nanostructure and phase variation of CuInSex nanopowders were investigated by different characterization techniques. The recrystallization process of the 12 μm thick CuInSex coatings into the CuInSe2 phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSex precursors with lower selenium content showed a more pronounced phase conversion into CuInSe2 compared to the higher selenium content CuInSex precursors. Moreover, the CuInSex (x = 0.5 and 1) precursor resulted in a denser polycrystalline CuInSe2 semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSex precursor system compared to a CuInSe2 phase precursor, and the formation of intermediate CuSe and CuSe2 fluxing phases during selenization. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lausanne | Editor | ||
Language | Wos | 000352225900004 | Publication Date | 2014-10-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0040-6090; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.879 | Times cited | 7 | Open Access | |
Notes | Approved | Most recent IF: 1.879; 2014 IF: 1.759 | |||
Call Number | c:irua:121330 | Serial | 834 | ||
Permanent link to this record | |||||
Author | Batuk, M.; Buffiere, M.; Zaghi, A.E.; Lenaers, N.; Verbist, C.; Khelifi, S.; Vleugels, J.; Meuris, M.; Hadermann, J. | ||||
Title ![]() |
Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se2 solar cells | Type | A1 Journal article | ||
Year | 2015 | Publication | Thin solid films : an international journal on the science and technology of thin and thick films | Abbreviated Journal | Thin Solid Films |
Volume | 583 | Issue | 583 | Pages | 142-150 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In,Ga)Se-2 (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aimof improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior to the selenization. We showed that the use of an Air/H2S burn-out step prior to the selenization step increases the CIGSe grain size and reduces the carbon content. However, it leads to the reduction of the solar cell efficiency from 4.5% in the reference sample down to 0.5% in the annealed sample. Detailed transmission electron microscopy analysis, including high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray mapping, was applied to characterize the microstructure of the film and to determine the relationship between microstructure and the solar cell performance. We demonstrated that the relatively low efficiency of the reference solar cells is related not only to the nanosize of the CIGSe grains and presence of the pores in the CIGSe layer, but also to the high amount of secondary phases, namely, In/Ga oxide (or hydroxide) amorphous matter, residuals of organicmatter (carbon), and copper sulfide that is formed at the CIGSe/MoSe2 interface. The annealing in H2S during the burn-out step leads to the formation of the copper sulfide at all grain boundaries and surfaces in the CIGSe layer, which results in the noticeably efficiency drop. (C) 2015 Elsevier B.V. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lausanne | Editor | ||
Language | Wos | 000353812400024 | Publication Date | 2015-04-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0040-6090; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.879 | Times cited | 5 | Open Access | |
Notes | Approved | Most recent IF: 1.879; 2015 IF: 1.759 | |||
Call Number | c:irua:126009 | Serial | 845 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Chevalier, J.; Olagnon, C.; Batuk, M.; Hadermann, J.; Van Meerbeek, B.; Vleugels, J. | ||||
Title ![]() |
Grain-boundary engineering for aging and slow-crack-growth resistant zirconia | Type | A1 Journal article | ||
Year | 2017 | Publication | Journal of dental research | Abbreviated Journal | J Dent Res |
Volume | 96 | Issue | 7 | Pages | 774-779 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Ceramic materials are prone to slow crack growth, resulting in strength degradation over time. Although yttria-stabilized zirconia (Y-TZP) ceramics have higher crack resistance than other dental ceramics, their aging susceptibility threatens their long-term performance in aqueous environments such as the oral cavity. Unfortunately, increasing the aging resistance of Y-TZP ceramics normally reduces their crack resistance. Our recently conducted systematic study of doping 3Y-TZP with various trivalent cations revealed that lanthanum oxide (La2O3) and aluminum oxide (Al2O3) have the most potent effect to retard the aging kinetics of 3Y-TZP. In this study, the crack-propagation behavior of La2O3 and Al2O3 co-doped 3Y-TZP ceramics was investigated by double-torsion methods. The grain boundaries were examined using scanning transmission electron microscopy and energy-dispersive spectroscopy (STEM-EDS). Correlating these analytic data with hydrothermal aging studies using different doping systems, a strategy to strongly bind the segregated dopant cations with the oxygen vacancies at the zirconia-grain boundary was found to improve effectively the aging resistance of Y-TZP ceramics without affecting the resistance to crack propagation. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | St. Louis, Mo. | Editor | ||
Language | Wos | 000403934500010 | Publication Date | 2017-03-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-0345 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.755 | Times cited | 3 | Open Access | Not_Open_Access |
Notes | ; This research was supported by the Research Fund of KU Leuven under project 0T/ 10/052 and the Research Foundation-Flanders (FWO-Vlaanderen) under grant G.0431.10N. We thank J.W. Seo for TEM and sample preparations. F. Zhang thanks the Research Fund of KU Leuven for her postdoctoral fellowship (PDM/15/153) and the JECS-Trust for the travel grant (No. 201599) to perform double-torsion testing in the MATEIS lab of INSA, Lyon, France. Jerome Chevalier would like to dedicate this paper to Maria Cattani Lorente, who recently passed away under tragic conditions. She was deeply involved in the study of dental zirconia and we will miss her. The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article. ; | Approved | Most recent IF: 4.755 | ||
Call Number | UA @ lucian @ c:irua:144161 | Serial | 4660 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Vanmeensel, K.; Batuk, M.; Hadermann, J.; Inokoshi, M.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
Title ![]() |
Highly-translucent, strong and aging-resistant 3Y-TZP ceramics for dental restoration by grain boundary segregation | Type | A1 Journal article | ||
Year | 2015 | Publication | Acta biomaterialia | Abbreviated Journal | Acta Biomater |
Volume | 16 | Issue | 16 | Pages | 215-222 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Latest trends in dental restorative ceramics involve the development of full-contour 3Y-TZP ceramics which can avoid chipping of veneering porcelains. Among the challenges are the low translucency and the hydrothermal stability of 3Y-TZP ceramics. In this work, different trivalent oxides (Al2O3, Sc2O3, Nd2O3 and La2O3) were selected to dope 3Y-TZP ceramics. Results show that dopant segregation was a key factor to design hydrothermally stable and high-translucent 3Y-TZP ceramics and the cation dopant radius could be used as a controlling parameter. A large trivalent dopant, oversized as compared to Zr4+, exhibiting strong segregation at the ZrO2 grain boundary was preferred. The introduction of 0.2 mol% La2O3 in conventional 0.10.25 wt.% Al2O3-doped 3Y-TZP resulted in an excellent combination of high translucency and superior hydrothermal stability, while retaining excellent mechanical properties. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | S.l. | Editor | ||
Language | Wos | 000351978600021 | Publication Date | 2015-02-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1742-7061; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.319 | Times cited | 54 | Open Access | |
Notes | Fwo G043110n | Approved | Most recent IF: 6.319; 2015 IF: 6.025 | ||
Call Number | c:irua:124421 | Serial | 1473 | ||
Permanent link to this record | |||||
Author | Zhang, L.; Vleugels, J.; Darchuk, L.; van der Biest, O. | ||||
Title ![]() |
Magnetic field oriented tetragonal zirconia with anisotropic toughness | Type | A1 Journal article | ||
Year | 2011 | Publication | Journal of the European Ceramic Society | Abbreviated Journal | |
Volume | 31 | Issue | 8 | Pages | 1405-1412 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | (0 0 1)-oriented 3 mol% yttria stabilized tetragonal zirconia (3Y-TZP) has been developed by reactive synthesis of undoped pure monoclinic zirconia and co-precipitated 8 mol% yttria-stabilized zirconia (8Y-ZrO2). The dispersed pure monoclinic ZrO2 powder, having magnetic anisotropy, was first aligned in a strong magnetic field and co-sintered in a randomly distributed cubic 8Y-ZrO2 fine matrix powder. The reactive sintering resulted in a 3Y-TZP ceramic with a (0 0 1) orientation. The (0 0 1)-oriented 3Y-TZP showed a substantial toughness anisotropy, i.e. the toughness along the [0 0 1] direction is 54% higher than that of its perpendicular direction. Moreover, the toughness along the [0 0 1] direction is 49% higher than that of a non-textured isotropic reactively synthesized 3Y-TZP and 110% higher than that of an isotropic co-precipitated powder based 3Y-TZP. The substantially enhanced toughness was interpreted in terms of the tetragonal to monoclinic martensitic phase transformability. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000290189100008 | Publication Date | 2011-03-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0955-2219 | 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:89722 | Serial | 8192 | ||
Permanent link to this record | |||||
Author | Zaghi, A.E.; Buffière, M.; Brammertz, G.; Batuk, M.; Lenaers, N.; Kniknie, B.; Hadermann, J.; Meuris, M.; Poortmans, J.; Vleugels, J. | ||||
Title ![]() |
Mechanical synthesis of high purity Cu-In-Se alloy nanopowder as precursor for printed CISe thin film solar cells | Type | A1 Journal article | ||
Year | 2014 | Publication | Advanced powder technology | Abbreviated Journal | Adv Powder Technol |
Volume | 25 | Issue | 4 | Pages | 1254-1261 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Mechanical alloying and ball milling are low cost, up-scalable techniques for the preparation of high purity chalcogenide nanopowders to be used as precursor material for printing thin film solar cells. In this study, high purity copper indium selenium (Cu-In-Se) alloy nanopowders with 20-200 nm particle size were synthesized from macroscopic elemental Cu, In and Se powders via mechanical alloying and planetary ball milling. The particle size distribution, morphology, composition, and purity level of the synthesized Cu-In-Se alloy nanopowders were investigated. Thin Cu-In-Se alloy nanopowder ink coatings, deposited on Mo-coated glass substrates by doctor blading, were converted into a CuInSe2 semiconductor film by selenization heat treatment in Se vapor. The CuInSe2 film showed semiconducting band gap around 1 eV measured by photoluminescence spectroscopy. CuInSe2 absorber layer based thin film solar cell devices were fabricated to assess their performance. The solar cell device showed a total efficiency of 4.8%, as measured on 0.25 cm(2) area cell. (c) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Zeist | Editor | ||
Language | Wos | 000341871700015 | Publication Date | 2014-03-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0921-8831; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.659 | Times cited | 10 | Open Access | |
Notes | Approved | Most recent IF: 2.659; 2014 IF: 2.638 | |||
Call Number | UA @ lucian @ c:irua:119896 | Serial | 1977 | ||
Permanent link to this record | |||||
Author | Xu, T.; Wang, P.; Fang, P.; Kan, Y.; Chen, L.; Vleugels, J.; Van der Biest, O.; van Landuyt, J. | ||||
Title ![]() |
Phase assembly and microstructure of CeO2-doped ZrO2 ceramics prepared by spark plasma sintering | Type | A1 Journal article | ||
Year | 2005 | Publication | Journal of the European Ceramic Society | Abbreviated Journal | J Eur Ceram Soc |
Volume | 25 | Issue | 15 | Pages | 3437-3442 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | CeO2-doped ZrO2, (8 mol%) starting powder was sintered by means of spark plasma sintering (SPS) at 1300 degrees C without holding time. The stability of the tetragonal ZrO2 phase in the Ce-ZrO2 ceramic sintered under strongly reducing conditions was investigated. The SPS sample consisted of monoclinic and tetragonal ZrO2 phase, with a volume ratio of two to one, as well as a trace amount of a Zr-Ce-O cubic solid solution phase. In contrast, the same powder sintered by hot-pressing in nitrogen at 1300 and 1500 degrees C for 1h showed no tetragonal ZrO2. Microstructural observation of the SPS ceramic by SEM and TEM revealed grains with and without twins. The reason for the appearance of the tetragonal phase in the SPS sample sintered under strongly reducing conditions is discussed. (c) 2004 Elsevier Ltd. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Barking | Editor | ||
Language | Wos | 000232172100006 | Publication Date | 2004-12-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0955-2219; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 13 | Open Access | |
Notes | Approved | Most recent IF: 3.411; 2005 IF: 1.567 | |||
Call Number | UA @ lucian @ c:irua:104065 | Serial | 2576 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. | ||||
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 | 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. | ||||
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 | 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 | Tunca, B.; Lapauw, T.; Delville, R.; Neuville, D.R.; Hennet, L.; Thiaudiere, D.; Ouisse, T.; Hadermann, J.; Vleugels, J.; Lambrinou, K. | ||||
Title ![]() |
Synthesis and Characterization of Double Solid Solution (Zr,Ti)(2)(Al,Sn)C MAX Phase Ceramics | Type | A1 Journal article | ||
Year | 2019 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
Volume | 58 | Issue | 10 | Pages | 6669-6683 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Quasi phase-pure (>98 wt %) MAX phase solid solution ceramics with the (ZryTi)(2)(Al-0.5,Sn-0.5)C stoichiometry and variable Zr/Ti ratios were synthesized by both reactive hot pressing and pressureless sintering of ZrH2, TiH2, Al, Sn, and C powder mixtures. The influence of the different processing parameters, such as applied pressure and sintering atmosphere, on phase purity and microstructure of the produced ceramics was investigated. The addition of Sn to the (Zr,Ti)(2)AlC system was the key to achieve phase purity. Its effect on the crystal structure of a 211-type MAX phase was assessed by calculating the distortions of the octahedral M6C and trigonal M(6)A prisms due to steric effects. The M(6)A prismatic distortion values were found to be smaller in Sn-containing double solid solutions than in the (Zr,Ti)(2)AlC MAX phases. The coefficients of thermal expansion along the < a > and < c > directions were measured by means of Rietveld refinement of high-temperature synchrotron X-ray diffraction data of (Zr1-x,Ti-x)(2)(Al-0.5,Sn-0.5)C MAX phase solid solutions with x = 0, 0.3, 0.7, and 1. The thermal expansion coefficient data of the Ti-2(Al-0.5,Sn-0.5)C solid solution were compared with those of the Ti2AlC and Ti2SnC ternary compounds. The thermal expansion anisotropy increased in the (Zr,Ti)(2)(Al-0.5,Sn-0.5)C double solid solution MAX phases as compared to the Zr-2(Al-0.5,Sn-0.5)C and Ti-2(Al-0.5,Sn-0.5)C end-members. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000469304700014 | Publication Date | 2019-05-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 3 | Open Access | Not_Open_Access |
Notes | ; H. Roussel and D. Pinek are acknowledged for the Ti<INF>2</INF>SnC single-crystal production and high-temperature XRD measurements performed at Grenoble INP-LMGP-CMTC. This research was funded partly by the European Atomic Energy Community's (Euratom) Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 604862 (FP7MatISSE), and partly by the Euratom research and training programme 2014-2018 under Grant Agreement No. 740415 (H2020 IL TROVATORE). T.L. thanks the Agency for Innovation by Science and Technology (IWT), Flanders, Belgium, for Ph.D. Grant No. 131081. B.T. acknowledges the financial support of the SCK.CEN Academy for Nuclear Science and Technology. All authors gratefully acknowledge Synchrotron SOLEIL for the allocated time at the DIFFABS beamline in association with Project 20161410 entitled “Investigation of (Zr-Ti)-Al-C MAX phases with in-situ high-temperature XRD” and the Hercules Foundation for Project AKUL/1319 (CombiS(T)EM). ; | Approved | Most recent IF: 4.857 | ||
Call Number | UA @ admin @ c:irua:160318 | Serial | 5261 | ||
Permanent link to this record | |||||
Author | Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J. | ||||
Title ![]() |
Synthesis of MAX Phases in the Zr-Ti-Al-C System | Type | A1 Journal article | ||
Year | 2017 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
Volume | 56 | Issue | 56 | Pages | 3489-3498 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000397171100045 | Publication Date | 2017-03-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 26 | Open Access | OpenAccess |
Notes | Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @ c:irua:141794 | Serial | 4491 | ||
Permanent link to this record |