toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Idrissi, H.; Cordier, P.; Jacob, D.; Walte, N. doi  openurl
  Title (down) Dislocations and plasticity of experimentally deformed coesite Type A1 Journal article
  Year 2008 Publication European journal of mineralogy Abbreviated Journal Eur J Mineral  
  Volume 20 Issue 4 Pages 665-671  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Dislocation microstructures have been characterized by transmission electron microscopy in polycrystalline coesite deformed experimentally at 4 GPa, 1200 degrees C. Burgers vectors have been determined by large-angle convergent-beam electron diffraction. Sample orientation was assisted by precession electron diffraction to overcome difficulties arising from pseudo-hexagonal symmetry. The results are explained by using a pseudo-hexagonal setting. We found that most dislocations observed are of the 1/3 < 2 (1) over bar(1) over bar0 > type. No clear glide plane was identified, suggesting that climb is activated under these conditions. This conclusion is supported by the observation of numerous subgrain boundaries. We have also observed some [00011 dislocations. Finally, the C12/cl space group to which coesite belongs being centred, an additional slip system is observed: 1/6[(1) over bar2 (1) over bar3](01 (1) over bar1) (1/2[(1) over bar 10](110) in the monoclinic setting).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Stuttgart Editor  
  Language Wos 000262891900021 Publication Date 2008-08-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0935-1221; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.362 Times cited 5 Open Access  
  Notes Approved Most recent IF: 1.362; 2008 IF: 1.220  
  Call Number UA @ lucian @ c:irua:94604 Serial 733  
Permanent link to this record
 

 
Author Amin-Ahmadi, B.; Connétable, D.; Fivel, M.; Tanguy, D.; Delmelle, R.; Turner, S.; Malet, L.; Godet, S.; Pardoen, T.; Proost, J.; Schryvers, D.; Idrissi, H. pdf  url
doi  openurl
  Title (down) Dislocation/hydrogen interaction mechanisms in hydrided nanocrystalline palladium films Type A1 Journal article
  Year 2016 Publication Acta materialia Abbreviated Journal Acta Mater  
  Volume 111 Issue 111 Pages 253-261  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The nanoscale plasticity mechanisms activated during hydriding cycles in sputtered nanocrystalline Pd films have been investigated ex-situ using advanced transmission electron microscopy techniques. The internal stress developing within the films during hydriding has been monitored in-situ. Results showed that in Pd films hydrided to β-phase, local plasticity was mainly controlled by dislocation activity in spite of the small grain size. Changes of the grain size distribution and the crystallographic texture have not been observed. In contrast, significant microstructural changes were not observed in Pd films hydrided to α-phase. Moreover, the effect of hydrogen loading on the nature and density of dislocations has been investigated using aberration-corrected TEM. Surprisingly, a high density of shear type stacking faults has been observed after dehydriding, indicating a significant effect of hydrogen on the nucleation energy barriers of Shockley partial dislocations. Ab-initio calculations of the effect of hydrogen on the intrinsic stable and unstable stacking fault energies of palladium confirm the experimental observations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000375812100027 Publication Date 2016-04-06  
  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 14 Open Access  
  Notes This work was carried out in the framework of the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. The support of the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations” for B. Amin-Ahmadi is also gratefully acknowledged. This work was granted access to the HPC resources of CALMIP (CICT Toulouse, France) under the allocations 2014-p0912 and 2014-p0749. Approved Most recent IF: 5.301  
  Call Number c:irua:132678 Serial 4054  
Permanent link to this record
 

 
Author Colla, M.-S.; Amin-Ahmadi, B.; Idrissi, H.; Malet, L.; Godet, S.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. pdf  url
doi  openurl
  Title (down) Dislocation-mediated relaxation in nanograined columnar ​palladium films revealed by on-chip time-resolved HRTEM testing Type A1 Journal article
  Year 2015 Publication Nature communications Abbreviated Journal Nat Commun  
  Volume 6 Issue 6 Pages 5922  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The high-rate sensitivity of nanostructured metallic materials demonstrated in the recent literature is related to the predominance of thermally activated deformation mechanisms favoured by a large density of internal interfaces. Here we report time-resolved high-resolution electron transmission microscopy creep tests on thin nanograined films using on-chip nanomechanical testing. Tests are performed on ​palladium, which exhibited unexpectedly large creep rates at room temperature. Despite the small 30-nm grain size, relaxation is found to be mediated by dislocation mechanisms. The dislocations interact with the growth nanotwins present in the grains, leading to a loss of coherency of twin boundaries. The density of stored dislocations first increases with applied deformation, and then decreases with time to drive additional deformation while no grain boundary mechanism is observed. This fast relaxation constitutes a key issue in the development of various micro- and nanotechnologies such as ​palladium membranes for hydrogen applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000348742300002 Publication Date 2015-01-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited 34 Open Access  
  Notes Iap7/21; Fwo G012012n Approved Most recent IF: 12.124; 2015 IF: 11.470  
  Call Number c:irua:122045 Serial 731  
Permanent link to this record
 

 
Author Samaee, V.; Sandfeld, S.; Idrissi, H.; Groten, J.; Pardoen, T.; Schwaiger, R.; Schryvers, D. pdf  url
doi  openurl
  Title (down) Dislocation structures and the role of grain boundaries in cyclically deformed Ni micropillars Type A1 Journal article
  Year 2020 Publication Materials Science And Engineering A-Structural Materials Properties Microstructure And Processing Abbreviated Journal Mat Sci Eng A-Struct  
  Volume 769 Issue Pages 138295  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Transmission electron microscopy and finite element-based dislocation simulations were combined to study the development of dislocation microstructures after cyclic deformation of single crystal and bicrystal Ni micropillars oriented for multi-slip. A direct correlation between large accumulation of plastic strain and the presence of dislocation cell walls in the single crystal micropillars was observed, while the presence of the grain boundary hampered the formation of wall-like structures in agreement with a smaller accumulated plastic strain. Automated crystallographic orientation and nanostrain mapping using transmission electron microscopy revealed the presence of lattice heterogeneities associated to the cell walls including long range elastic strain fields. By combining the nanostrain mapping with an inverse modelling approach, information about dislocation density, line orientation and Burgers vector direction was derived, which is not accessible otherwise in such dense dislocation structures. Simulations showed that the image forces associated with the grain boundary in this specific bicrystal configuration have only a minor influence on dislocation behavior. Thus, the reduced occurrence of “mature” cell walls in the bicrystal can be attributed to the available volume, which is too small to accommodate cell structures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000500373800018 Publication Date 2019-08-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-5093 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.4 Times cited 1 Open Access OpenAccess  
  Notes Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N,SCHW855/5-1, and SA2292/2-1 is gratefully acknowledged. V.S. acknowledges the FWO research project G012012 N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). S.S. acknowledges financial support from the European Research Council through the ERC Grant Agreement No. 759419 (MuDiLingo – A Multiscale Dislocation Language for Data- Driven Materials Science). Approved Most recent IF: 6.4; 2020 IF: 3.094  
  Call Number EMAT @ emat @c:irua:163475 Serial 5371  
Permanent link to this record
 

 
Author Samaee, V.; Gatti, R.; Devincre, B.; Pardoen, T.; Schryvers, D.; Idrissi, H. url  doi
openurl 
  Title (down) Dislocation driven nanosample plasticity: new insights from quantitative in-situ TEM tensile testing Type A1 Journal Article
  Year 2018 Publication Scientific Reports Abbreviated Journal Sci Rep-Uk  
  Volume 8 Issue 1 Pages 12012  
  Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;  
  Abstract Intrinsic dislocation mechanisms in the vicinity of free surfaces of an almost FIB damage-free single crystal Ni sample have been quantitatively investigated owing to a novel sample preparation method combining twin-jet electro-polishing, in-situ TEM heating and FIB. The results reveal that the small-scale plasticity is mainly controlled by the conversion of few tangled dislocations, still present after heating, into stable single arm sources (SASs) as well as by the successive operation of these sources. Strain hardening resulting from the operation of an individual SAS is reported and attributed to the decrease of the length of the source. Moreover, the impact of the shortening of the dislocation source on the intermittent plastic flow, characteristic of SASs, is discussed. These findings provide essential information for the understanding of the regime of ‘dislocation source’ controlled plasticity and the related mechanical size effect.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000460200900001 Publication Date 2018-08-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited 9 Open Access Not_Open_Access  
  Notes Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaee also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Dr. Ruth Schwaiger is acknowledged for providing the Ni foils used to prepare the in-situ TEM tensile specimens. Approved Most recent IF: 4.259  
  Call Number EMAT @ emat @c:irua:155772 Serial 5136  
Permanent link to this record
 

 
Author Lemoine, G.; Delannay, L.; Idrissi, H.; Colla, M.-S.; Pardoen, T. pdf  doi
openurl 
  Title (down) Dislocation and back stress dominated viscoplasticity in freestanding sub-micron Pd films Type A1 Journal article
  Year 2016 Publication Acta materialia Abbreviated Journal Acta Mater  
  Volume 111 Issue 111 Pages 10-21  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract A dislocation-based crystal plasticity model is developed in order to study the mechanical and creep/ relaxation behaviour of polycrystalline metallic thin films. The model accounts for the confinement of plasticity due to grain boundaries and for the anisotropy of individual grains, as well as for the significant viscoplastic effects associated to dislocation dominated thermally activated mechanisms. Numerical predictions are assessed based on experimental tensile test followed by relaxation on freestanding Pd films, based on an on-chip test technique. The dislocation-based mechanism assumption captures all the experimental trends, including the stress strain response, the relaxation behaviour and the dislocation density evolution, confirming the dominance of a dislocation driven deformation mechanism for the present Pd films with high defects density. The model has also been used to address some original experimental evidences involving back stresses, Bauschinger effect, backward creep and strain recovery. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Oxford Editor  
  Language Wos 000375812100002 Publication Date 2016-03-26  
  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 6 Open Access  
  Notes Approved Most recent IF: 5.301  
  Call Number UA @ lucian @ c:irua:133636 Serial 4162  
Permanent link to this record
 

 
Author Turner, S.; Idrissi, H.; Sartori, A.F.; Korneychuck, S.; Lu, Y.-G.; Verbeeck, J.; Schreck, M.; Van Tendeloo, G. url  doi
openurl 
  Title (down) Direct imaging of boron segregation at dislocations in B:diamond heteroepitaxial films Type A1 Journal article
  Year 2016 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 8 Issue 8 Pages 2212-2218  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission electron microscopy techniques, revealing the presence of two types of dislocations: edge and mixed-type 45 degrees dislocations. The presence and distribution of B in the sample was studied using annular dark-field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these techniques, a segregation of B at the dislocations in the film is evidenced, which is shown to be intermittent along the dislocation. A single edge-type dislocation was selected to study the distribution of the boron surrounding the dislocation core. By imaging this defect at atomic resolution, the boron is revealed to segregate towards the tensile strain field surrounding the edge-type dislocations. An investigation of the fine structure of the B-K edge at the dislocation core shows that the boron is partially substitutionally incorporated into the diamond lattice and partially present in a lower coordination (sp(2)-like hybridization).  
  Address EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. stuart.turner@uantwerpen.be  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000368860900053 Publication Date 2015-12-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 15 Open Access  
  Notes S. T. acknowledges the fund for scien tific research Flanders (FWO) for a post-doctoral scholarship and under contract number G.0044.13N Approved Most recent IF: 7.367  
  Call Number c:irua:131597UA @ admin @ c:irua:131597 Serial 4121  
Permanent link to this record
 

 
Author Schryvers, D.; Van Aert, S.; Delville, R.; Idrissi, H.; Turner, S.; Salje, E.K.H. pdf  doi
openurl 
  Title (down) Dedicated TEM on domain boundaries from phase transformations and crystal growth Type A1 Journal article
  Year 2013 Publication Phase transitions Abbreviated Journal Phase Transit  
  Volume 86 Issue 1 Pages 15-22  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Investigating domain boundaries and their effects on the behaviour of materials automatically implies the need for detailed knowledge on the structural aspects of the atomic configurations at these interfaces. Not only in view of nearest neighbour interactions but also at a larger scale, often surpassing the unit cell, the boundaries can contain structural elements that do not exist in the bulk. In the present contribution, a number of special boundaries resulting from phase transformations or crystal growth and those recently investigated by advanced transmission electron microscopy techniques in different systems will be reviewed. These include macrotwins between microtwinned martensite plates in NiAl, austenite-single variant martensite habit planes in low hysteresis NiTiPd, nanotwins in non-textured nanostructured Pd and ferroelastic domain boundaries in CaTiO3. In all discussed cases these boundaries play an essential role in the properties of the respective materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos 000312586700003 Publication Date 2012-12-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0141-1594;1029-0338; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.06 Times cited Open Access  
  Notes Fwo; Iap Approved Most recent IF: 1.06; 2013 IF: 1.044  
  Call Number UA @ lucian @ c:irua:101222 Serial 612  
Permanent link to this record
 

 
Author Samaee, V.; Dupraz, M.; Pardoen, T.; VAn Swygenhoven, H.; Schryvers, D.; Idrissi, H. url  doi
openurl 
  Title (down) Deciphering the interactions between single arm dislocation sources and coherent twin boundary in nickel bi-crystal Type A1 Journal article
  Year 2021 Publication Nature Communications Abbreviated Journal Nat Commun  
  Volume 12 Issue 1 Pages 962  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The introduction of a well-controlled population of coherent twin boundaries (CTBs) is an attractive route to improve the strength ductility product in face centered cubic (FCC) metals. However, the elementary mechanisms controlling the interaction between single arm dislocation sources (SASs), often present in nanotwinned FCC metals, and CTB are still not well understood. Here, quantitative in-situ transmission electron microscopy (TEM) observations of these mechanisms under tensile loading are performed on submicron Ni bi-crystal. We report that the absorption of curved screw dislocations at the CTB leads to the formation of constriction nodes connecting pairs of twinning dislocations at the CTB plane in agreement with large scale 3D atomistic simulations. The coordinated motion of the twinning dislocation pairs due to the presence of the nodes leads to a unique CTB sliding mechanism, which plays an important role in initiating the fracture process at a CTB ledge. TEM observations of the interactions between non-screw dislocations and the CTB highlight the importance of the synergy between the repulsive force of the CTB and the back stress from SASs when the interactions occur in small volumes. Interactions of dislocations with coherent twin boundaries contribute to strength and ductility in metals, but investigating the interaction mechanisms is challenging. Here the authors unravel these mechanisms through quantitative in-situ transmission electron microscopy observations in nickel bi-crystal samples under tensile loading.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000620142700024 Publication Date 2021-02-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 12.124  
  Call Number UA @ admin @ c:irua:176680 Serial 6722  
Permanent link to this record
 

 
Author Sandfeld, S.; Samaee, V.; Idrissi, H.; Groten, J.; Pardoen, T.; Schwaiger, R.; Schryvers, D. url  doi
openurl 
  Title (down) Datasets for the analysis of dislocations at grain boundaries and during vein formation in cyclically deformed Ni micropillars Type A1 Journal article
  Year 2019 Publication Data in Brief Abbreviated Journal  
  Volume 27 Issue 27 Pages 104724  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The dataset together with the corresponding Python scripts and Jupyter notebooks presented in this article are supplementary data for the work presented in Samaee et al., 2019 [1]. The data itself consists of two parts: the simulation data that was used in [1] to analyze the effect of a particular grain boundary on curved dislocations and the precession electron diffraction (PED) strain maps together with post-processed data for analyzing details of the observed dislocation vein structures. Additionally, the complete stress tensor components, which are not shown in [1], have also been included. The data sets are accompanied by Python code explaining the file formats and showing how to post-process the data. (c) 2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000501988200181 Publication Date 2019-11-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2352-3409 ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:165092 Serial 6292  
Permanent link to this record
 

 
Author Zhao, L.; Macias, J.G.S.; Ding, L.; Idrissi, H.; Simar, A. pdf  doi
openurl 
  Title (down) Damage mechanisms in selective laser melted AlSi10Mg under as built and different post-treatment conditions Type A1 Journal article
  Year 2019 Publication Microstructure And Processing Abbreviated Journal Mat Sci Eng A-Struct  
  Volume 764 Issue 764 Pages 138210  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Selective laser melting (SLM) manufactured AlSi10Mg alloys present a fine silicon-rich network and precipitates which grant high mechanical strength but low ductility. Post-treatments, aiming at eliminating inherent defects related to SLM such as residual stresses, porosity or inhomogeneity, result in significant changes in the microstructure and impact both the hardening and the damage mechanisms of the post-treated material. The present work is dedicated to the investigation of the fracture of SLM AlSi10Mg under as built and three post-treatment conditions, namely two stress relieve heat treatments and friction stir processing (FSP). It is found that the interconnected Si network fosters damage at low strain due to the brittleness of the Si phase. The onset of damage transfers load to the enclosed Al phase which then fractures quickly under high stress, thus leading to low material ductility. In contrast, when the Si network is globularized into Si particles, the ductility is highly increased even in the case where the porosity and inhomogeneity of the microstructure remain after the post-treatment. The ductility enhancement results from the delay in void nucleation on the Si particles as well as from the tolerance for void growth in the Al matrix.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000486360100029 Publication Date 2019-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-5093 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.094 Times cited 1 Open Access  
  Notes ; This research work has been supported by the WALInnov LongLifeAM project, Convention n 1810016, funded by Service public de Wallonie Economic Emploi Recherche (SPW-EER). L. Ding and A. Simar acknowledge the financial support of the European Research Council (ERC) for the Starting Grant ALUFIX project (grant agreement n 716678). J. G. Santos Macias acknowledges the support of the Fonds de la recherche scientifique -FNRS (FRIA grant), Belgium. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSRFNRS). Any-Shape is acknowledged for material supply. We thank Prof. P. J. Jacques from UCLouvain for fruitful discussion and critical reading of the paper. ; Approved Most recent IF: 3.094  
  Call Number UA @ admin @ c:irua:162800 Serial 5386  
Permanent link to this record
 

 
Author Tang, X.; Reckinger, N.; Poncelet, O.; Louette, P.; Urena, F.; Idrissi, H.; Turner, S.; Cabosart, D.; Colomer, J.-F.; Raskin, J.-P.; Hackens, B.; Francis, L.A. pdf  url
doi  openurl
  Title (down) Damage evaluation in graphene underlying atomic layer deposition dielectrics Type A1 Journal article
  Year 2015 Publication Scientific reports Abbreviated Journal Sci Rep-Uk  
  Volume 5 Issue 5 Pages 13523  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Based on micro-Raman spectroscopy (muRS) and X-ray photoelectron spectroscopy (XPS), we study the structural damage incurred in monolayer (1L) and few-layer (FL) graphene subjected to atomic-layer deposition of HfO2 and Al2O3 upon different oxygen plasma power levels. We evaluate the damage level and the influence of the HfO2 thickness on graphene. The results indicate that in the case of Al2O3/graphene, whether 1L or FL graphene is strongly damaged under our process conditions. For the case of HfO2/graphene, muRS analysis clearly shows that FL graphene is less disordered than 1L graphene. In addition, the damage levels in FL graphene decrease with the number of layers. Moreover, the FL graphene damage is inversely proportional to the thickness of HfO2 film. Particularly, the bottom layer of twisted bilayer (t-2L) has the salient features of 1L graphene. Therefore, FL graphene allows for controlling/limiting the degree of defect during the PE-ALD HfO2 of dielectrics and could be a good starting material for building field effect transistors, sensors, touch screens and solar cells. Besides, the formation of Hf-C bonds may favor growing high-quality and uniform-coverage dielectric. HfO2 could be a suitable high-K gate dielectric with a scaling capability down to sub-5-nm for graphene-based transistors.  
  Address ICTEAM Institute, Universite catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000360147400001 Publication Date 2015-08-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited 18 Open Access  
  Notes The authors thank the staff of UCL’s Winfab and Welcome for technical support. Xiaohui Tang is a senior research of UCL. This work is financially supported by the Multi-Sensor-Platform for Smart Building Management project (No. 611887) and the Action de Recherche Concertée (ARC) “StressTronics”, Communauté française de Belgique. Part of this work is financially supported by the Belgian Fund for Scientific Research (FRS-FNRS) under FRFC contract “Chemographene” (No. 2.4577.11). J.-F. Colomer and B. Hackens are Research Associates of FRS-FNRS. This research used resources of the Electron Microscopy Service located at the University of Namur (“Plateforme Technologique Morphologie – Imagerie”). This research used resources of the ELISE Service of the University of Namur. This Service is member of the “Plateforme Technologique SIAM”. The research leading to this work has received partial funding from the European Union Seventh Framework Program under grant agreement No 604391 Graphene Flagship. Approved Most recent IF: 4.259; 2015 IF: 5.578  
  Call Number c:irua:129193 Serial 3958  
Permanent link to this record
 

 
Author Boulay, E.; Nakano, J.; Turner, S.; Idrissi, H.; Schryvers, D.; Godet, S. pdf  doi
openurl 
  Title (down) Critical assessments and thermodynamic modeling of BaO-SiO2 and SiO2-TiO2 systems and their extensions into liquid immiscibility in the BaO-SiO2-TiO2 system Type A1 Journal article
  Year 2014 Publication Calphad computer coupling of phase diagrams and thermochemistry Abbreviated Journal Calphad  
  Volume 47 Issue Pages 68-82  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract This study discusses rational reproduction of liquid immiscibility in the BaO-SiO2-TiO2 system. While a ternary assessment requires sub-binary descriptions in the same thermodynamic model, the related sub-binary systems BaO-SiO2, BaO-TiO2 and SiO2-TiO2 liquid and solid phases have been evaluated using different thermodynamic models in the literature. In this study, BaO-SiO2 and SiO2-TiO2 were assessed using the Ionic Two Sublattice model (I2SL) based on experimental data from the literature. BaO-TiO2 was already assessed using this model. Binary descriptions developed were then used for the assessment of liquid immiscibility in the BaO-SiO2-TiO2 system. Ternary interaction parameters were found necessary for rational reproduction of the new ternary experimental data gathered in the present work. The model parameters for each system were evaluated using a CAPLHAD approach. A set of parameters is proposed. They show good agreement between the calculated and experimental equilibrium liquidus, liquid immiscibility and thermochemical properties in the BaO-SiO2-TiO2 system. (C) 2014 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Oxford Editor  
  Language Wos 000346224700008 Publication Date 2014-07-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0364-5916; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.6 Times cited 9 Open Access  
  Notes Approved Most recent IF: 1.6; 2014 IF: 1.370  
  Call Number UA @ lucian @ c:irua:122776 Serial 540  
Permanent link to this record
 

 
Author Krishnamurthy, S.C.; Arseenko, M.; Kashiwar, A.; Dufour, P.; Marchal, Y.; Delahaye, J.; Idrissi, H.; Pardoen, T.; Mertens, A.; Simar, A. pdf  url
doi  openurl
  Title (down) Controlled precipitation in a new Al-Mg-Sc alloy for enhanced corrosion behavior while maintaining the mechanical performance Type A1 Journal article
  Year 2023 Publication Materials characterization Abbreviated Journal  
  Volume 200 Issue Pages 112886-11  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The hot working of 5xxx series alloys with Mg ≥3.5 wt% is a concern due to the precipitation of β (Al3Mg2) phase at grain boundaries favoring Inter Granular Corrosion (IGC). The mechanical and corrosion properties of a new 5028-H116 Al-Mg-Sc alloy under various β precipitates distribution is analyzed by imposing different cooling rates from the hot forming temperature (i.e. 325 °C). The mechanical properties are maintained regardless of the heat treatment. However, the different nucleation sites and volume fractions of β precipitates for different cooling rates critically affect IGC. Controlled furnace cooling after the 325 °C heat treatment is ideal in 5028-H116 alloy to reduce susceptibility to IGC after sensitization.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000977059100001 Publication Date 2023-04-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.7 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 4.7; 2023 IF: 2.714  
  Call Number UA @ admin @ c:irua:195598 Serial 7291  
Permanent link to this record
 

 
Author Idrissi, H.; Ghidelli, M.; Béché, A.; Turner, S.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. url  doi
openurl 
  Title (down) Atomic-scale viscoplasticity mechanisms revealed in high ductility metallic glass films Type A1 Journal article
  Year 2019 Publication Scientific reports Abbreviated Journal Sci Rep-Uk  
  Volume 9 Issue 1 Pages 13426  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The fundamental plasticity mechanisms in thin freestanding Zr65Ni35 metallic glass films are investigated in order to unravel the origin of an outstanding strength/ductility balance. The deformation process is homogenous until fracture with no evidence of catastrophic shear banding. The creep/relaxation behaviour of the films was characterized by on-chip tensile testing, revealing an activation volume in the range 100–200 Å3. Advanced high-resolution transmission electron microscopy imaging and spectroscopy exhibit a very fine glassy nanostructure with well-defined dense Ni-rich clusters embedded in Zr-rich clusters of lower atomic density and a ~2–3 nm characteristic length scale. Nanobeam electron diffraction analysis reveals that the accumulation of plastic deformation at roomtemperature

correlates with monotonously increasing disruption of the local atomic order. These results provide experimental evidences of the dynamics of shear transformation zones activation in metallic glasses. The impact of the nanoscale structural heterogeneities on the mechanical properties including the rate dependent behaviour is discussed, shedding new light on the governing plasticity mechanisms in metallic glasses with initially heterogeneous atomic arrangement.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000486139700008 Publication Date 2019-09-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited Open Access  
  Notes H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T.0178.19. FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’) and Hercules fund ‘Direct electron detector for soft matter TEM’ from Flemish Government are acknowledged. Approved Most recent IF: 4.259  
  Call Number EMAT @ emat @c:irua:162786 Serial 5375  
Permanent link to this record
 

 
Author Ding, L.; Zhao, L.; Weng, Y.; Schryvers, D.; Liu, Q.; Idrissi, H. pdf  url
doi  openurl
  Title (down) Atomic-scale investigation of the heterogeneous precipitation in the E (Al₁₈Mg₃Cr₂) dispersoid of 7075 aluminum alloy Type A1 Journal article
  Year 2021 Publication Journal Of Alloys And Compounds Abbreviated Journal J Alloy Compd  
  Volume 851 Issue Pages 156890  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The heterogeneous precipitation of the eta (MgZn2) phase on the E (Al18Mg3Cr2) dispersoids of the 7075 aluminum alloy was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive X-ray spectrometry (EDX). It is found that coarse B particles are heterogeneously precipitated at the E particle interface after water quenching and isothermal aging at 120 degrees C. The incoherent E/Al interface is responsible for the high tendency of heterogeneous precipitation of the B phase. Two different orientation relationships (ORs) between the eta, E and Al matrix are identified: OR1 [2 (11) over bar0](eta)[011](E)//[(1) over bar 12](Al), (01 (1) over bar0)(eta)//(13 (3) over bar)(E)//(201)(Al), OR2 [(1) over bar 12](E)//[0001](eta)//[011](Al), (01 (1) over bar0 )(eta)//(220)(E)//(34 (4) over bar)(Al). The eta phase is preferential to nucleate along the {111}(E) or the {220}(E) planes, depending on its OR. The heterogeneous nucleation of B phase on the E particle could stabilize the E/Al interface by introducing a coherent E/eta interface, which increases the drive force of heterogeneous precipitation. The reorientation of eta phase and mutual diffusion of solute atoms could assist the coherency of the E/eta interface. The present results suggest that increasing the coherency of the E/Al interface is a promising method to suppress the heterogeneous precipitation of the eta phase. (C) 2020 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000579868900103 Publication Date 2020-08-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-8388 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.133 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 3.133  
  Call Number UA @ admin @ c:irua:173503 Serial 6717  
Permanent link to this record
 

 
Author Lumbeeck, G.; Delvaux, A.; Idrissi, H.; Proost, J.; Schryvers, D. url  doi
openurl 
  Title (down) Analysis of internal stress build-up during deposition of nanocrystalline Ni thin films using transmission electron microscopy Type A1 Journal article
  Year 2020 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal Thin Solid Films  
  Volume 707 Issue Pages 138076  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Ni thin films sputter-deposited at room temperature with varying Ar pressures were investigated with automated crystal orientation mapping in a transmission electron microscope to uncover the mechanisms controlling the internal stress build-up recorded in-situ during deposition. Large grains were found to induce behaviour similar to a stress-free nucleation layer. The measurements of grain size in most of the Ni thin films are in agreement with the island coalescence model. Low internal stress was observed at low Ar pressure and was explained by the presence of large grains. Relaxation of high internal stress was also noticed at the highest Ar pressure, which was attributed to a decrease of Σ3 twin boundary density due to a low deposition rate. The results provide insightful information to better understand the relationship between structural boundaries and the evolution of internal stress upon deposition of thin films.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000539312200011 Publication Date 2020-05-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes This work was supported by the Hercules Foundation [Grant No. AUHA13009], the Flemish Research Fund (FWO) [Grant No. G.0365.15N], and the Flemish Strategic Initiative for Materials (SIM) under the project InterPoCo. Thin film deposition has been realised as part of the WallonHY project, funded by the Public Service of Wallonia – Department of Energy and Sustainable Building. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Approved Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:169708 Serial 6370  
Permanent link to this record
 

 
Author Schryvers, D.; Cao, S.; Tirry, W.; Idrissi, H.; Van Aert, S. pdf  url
doi  openurl
  Title (down) Advanced three-dimensional electron microscopy techniques in the quest for better structural and functional materials Type A1 Journal article
  Year 2013 Publication Science and technology of advanced materials Abbreviated Journal Sci Technol Adv Mat  
  Volume 14 Issue 1 Pages 014206-14213  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract After a short review of electron tomography techniques for materials science, this overview will cover some recent results on different shape memory and nanostructured metallic systems obtained by various three-dimensional (3D) electron imaging techniques. In binary NiTi, the 3D morphology and distribution of Ni4Ti3 precipitates are investigated by using FIB/SEM slice-and-view yielding 3D data stacks. Different quantification techniques will be presented including the principal ellipsoid for a given precipitate, shape classification following a Zingg scheme, particle distribution function, distance transform and water penetration. The latter is a novel approach to quantifying the expected matrix transformation in between the precipitates. The different samples investigated include a single crystal annealed with and without compression yielding layered and autocatalytic precipitation, respectively, and a polycrystal revealing different densities and sizes of the precipitates resulting in a multistage transformation process. Electron tomography was used to understand the interaction between focused ion beam-induced Frank loops and long dislocation structures in nanobeams of Al exhibiting special mechanical behaviour measured by on-chip deposition. Atomic resolution electron tomography is demonstrated on Ag nanoparticles in an Al matrix.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Sendai Editor  
  Language Wos 000316463800008 Publication Date 2013-03-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1468-6996;1878-5514; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.798 Times cited 6 Open Access  
  Notes Fwo; Iap; Esteem Approved Most recent IF: 3.798; 2013 IF: 2.613  
  Call Number UA @ lucian @ c:irua:107343 Serial 77  
Permanent link to this record
 

 
Author Wang, B.; Idrissi, H.; Galceran, M.; Colla, M.S.; Turner, S.; Hui, S.; Raskin, J.P.; Pardoen, T.; Godet, S.; Schryvers, D. pdf  doi
openurl 
  Title (down) Advanced TEM investigation of the plasticity mechanisms in nanocrystalline freestanding palladium films with nanoscale twins Type A1 Journal article
  Year 2012 Publication International journal of plasticity Abbreviated Journal Int J Plasticity  
  Volume 37 Issue Pages 140-156  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Nanocrystalline palladium thin films deposited by electron-beam evaporation and deformed by on-chip tensile testing reveal a surprisingly large strain hardening capacity when considering the small similar to 25 nm grain size. The as-grown films contain several coherent single and multifold twin boundaries. The coherency of the twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions. These reactions are described based on a detailed analysis of the number and the type of dislocations located at the twin boundaries using high-resolution TEM, including aberration corrected microscopy. Sessile Frank dislocations were observed at the twin/matrix interfaces, explaining the loss of the TB coherency due to the Burgers vector pointing out of the twinning plane. Grain boundary mediated processes were excluded as a mechanism dominating the plastic deformation based on the investigation of the grain size distribution as well as the crystallographic texture using Automated Crystallographic Orientation Indexation TEM. Other factors influencing the plastic deformation such as impurities and the presence of a native passivation oxide layer at the surface of the films were investigated using analytical TEM. The twin boundaries observed in the present work partly explain the high strain hardening capacity by providing both increasing resistance to dislocation motion with deformation and a source for dislocation multiplication. (C) 2012 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Oxford Editor  
  Language Wos 000307416100009 Publication Date 2012-05-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0749-6419; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.702 Times cited 44 Open Access  
  Notes Iap; Fwo Approved Most recent IF: 5.702; 2012 IF: 4.356  
  Call Number UA @ lucian @ c:irua:101082 Serial 74  
Permanent link to this record
 

 
Author Pardoen, T.; Colla, M.-S.; Idrissi, H.; Amin-Ahmadi, B.; Wang, B.; Schryvers, D.; Bhaskar, U.K.; Raskin, J.-P. pdf  url
doi  openurl
  Title (down) A versatile lab-on-chip test platform to characterize elementary deformation mechanisms and electromechanical couplings in nanoscopic objects Type A1 Journal article
  Year 2016 Publication Comptes rendus : physique Abbreviated Journal Cr Phys  
  Volume 17 Issue 17 Pages 485-495  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A nanomechanical on-chip test platform has recently been developed to deform under a variety of loading conditions freestanding thin films, ribbons and nanowires involving submicron dimensions. The lab-on-chip involves thousands of elementary test structures from which the elastic modulus, strength, strain hardening, fracture, creep properties can be extracted. The technique is amenable to in situ transmission electron microscopy (TEM) investigations to unravel the fundamental underlying deformation and fracture mechanisms that often lead to size-dependent effects in small-scale samples. The method allows addressing electrical and magnetic couplings as well in order to evaluate the impact of large mechanical stress levels on different solid-state physics phenomena. We had the chance to present this technique in details to Jacques Friedel in 2012 who, unsurprisingly, made a series of critical and very relevant suggestions. In the spirit of his legacy, the paper will address both mechanics of materials related phenomena and couplings with solids state physics issues.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000373524300020 Publication Date 2015-12-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1631-0705 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.048 Times cited 7 Open Access  
  Notes This research has been performed with the financial support of the “Politique scientifique fédérale” under the framework of the interuniversity attraction poles program, IAP7/21, as well as with the support of the “Communauté française de Belgique” under the program “Actions de recherche concertées” ARC 05/10-330 and ARC Convention No. 11/16-037. The support of the “Fonds belge pour la recherche dans l'industrie et l'agriculture (FRIA)” for M.-S. Colla is also gratefully acknowledged as are the FWO research projects G012012N “Understanding nanocrystalline mechanical behavior from structural investigations” for B. Amin-Ahmadi. Approved Most recent IF: 2.048  
  Call Number c:irua:129995 Serial 4014  
Permanent link to this record
 

 
Author Arseenko, M.; Hannard, F.; Ding, L.; Zhao, L.; Maire, E.; Villanova, J.; Idrissi, H.; Simar, A. pdf  doi
openurl 
  Title (down) A new healing strategy for metals : programmed damage and repair Type A1 Journal article
  Year 2022 Publication Acta materialia Abbreviated Journal Acta Mater  
  Volume 238 Issue Pages 118241-10  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Self-healing strategies aim at avoiding part repair or even replacement, which is time consuming, expen-sive and generates waste. However, strategies for metallic systems are still under-developed and solid-state solutions for room temperature service are limited to nano-scale damage repair. Here we propose a new healing strategy of micron-sized damage requiring only short and low temperature heating. This new strategy is based on damage localization particles, which can be healed by fast diffusing atoms of the matrix activated during heat treatment. The healing concept was successfully validated with a com-mercial aluminum alloy and manufactured by Friction Stir Processing (FSP). Damage was demonstrated to initiate on particles that were added to the matrix during material processing. In situ 2D and 3D nano -imaging confirmed healing of the damaged material and showed that heating this material for 10 min at 400 degrees C is sufficient to heal incipient damage with complete filling of 70% of all damage (and up to 90% when their initial size is below 0.2 mu m). Furthermore, strength is retained and the work of fracture of the alloy is improved by about 40% after healing. The proposed Programmed Damage and Repair healing strategy could be extended to other metal based systems presenting precipitation. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000843502700006 Publication Date 2022-08-03  
  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 9.4 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 9.4  
  Call Number UA @ admin @ c:irua:190561 Serial 7121  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: