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“On the phase-like nature of the 7M structure in Ni-Al”. Schryvers D, Tanner LE, MRS Japan: shape memory materials 18, 849 (1993)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 1
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“Review of phonon behaviour and microstructural development leading to martensitic transformations in NixAl100-x alloys”. Tanner LE, Shapiro SM, Schryvers D, Noda Y, Shape memory materials and phenomena: fundamental aspects and applications 246, 265 (1992)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 4
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“Structural characterisation of nanostructured Ni3Al processed by inert gas condensation”. Yandouzi M, Pauwels B, Schryvers D, van Swygenhoven H, Van Tendeloo G, Defects and diffusion in metals 213/215, 19 (2003)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
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“Structural instabilities associated with phase transitions: an electron microscopy study”. Van Tendeloo G, Schryvers D, Tanner LE, , 107 (1992)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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“Structural phase transformations in alloys: an electron microscopy study”. Van Tendeloo G, Schryvers D, Tanner LE, Broddin D, Ricolleau C, Loiseau A, Symposium on Pahse Transformations , 1 (1991)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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“A temperature study of mixed AgBr-AgBrI tabular crystals”. Goessens C, Schryvers D, van Landuyt J, Geuens I, Gijbels R, Jacob W, de Keyzer R Hawaii, page 70 (1995).
Keywords: H1 Book chapter; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 3
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“A temperature study of mixed AgBr-AgBrI tabular crystals”. Goessens C, Schryvers D, van Landuyt J, Geuens I, Gijbels R, Jacob W, de Keyzer R, , 36 (1992)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Ni4Ti3 precipitates and their influence on the surrounding NiTi matrix”. Schryvers D, Tirry W, Yang Z, , 205 (2005)
Abstract: The properties of the shape memory behaviour of Ni-rich binary NiTi are strongly dependant on the thermal history of the material. In this respect the changing of transformation temperatures of the underlying martensitic transformation and the occurrence of multiple step transformations are the most important phenomena. Part of the explanation is found in the presence of Ni4Ti3 precipitates in the B2 matrix after particular heat treatments. The formation of these precipitates changes the Ni concentration of the matrix and induces a strain field, with both of these aspects expected to be of importance. In this work atomic resolution and analytical TEM (transmission electron microscopy) techniques are used to obtain quantitative information concerning these two main features. Furthermore, the known structure of Ni4Ti3 is refined by a least squares optimization of quantitative electron diffraction data. The high-resolution TEM results show that there are strains up to 2% in the matrix surrounding the precipitates and they gradually increase until a maximum is reached when moving away from the interface. Analytical results reveal a global decrease of Ni content in the matrix when sufficient precipitates are present and a gradient in their close vicinity. The refinement of the structure shows atomic displacements, thereby increasing our understanding of the shrinking of the precipitate lattice with respect to the matrix.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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Cautaerts N, Lamm S, Stergar E, Pakarinen J, Yang Y, Hofer C, Schnitzer R, Felfer P, Verwerft M, Delville R, Schryvers D (2020) Atom probe tomography data collection from DIN 1.4970 (15-15Ti) austenitic stainless steel irradiated with Fe ions
Abstract: This dataset comprises a large collection of atom probe tomography datasets collected from DIN 1.4970 alloy that was irradiated with Fe ions at different conditions. The DIN 1.4970 alloy is an austenitic stainless steel with 15 wt% Cr, 15 wt% Ni, a small addition of Ti. The full composition and characterization of our material can be found published elsewhere [1,2]. Some of our material was subjected to ageing heat treatments at different temperatures for different times. Small samples of our original material and aged material was irradiated at the Michigan Ion Beam Laboratory in 2017 with 4.5 MeV Fe ions up to 40 dpa at an average dose rate of 2×10−4 dpa/s. This was done at three different temperatures: 300, 450, and 600 ºC. Atom probe samples were made of the irradiated layers (approximately 1.5 micron deep) with focused ion beam and mounted on Microtip coupons. APT measurements took place on three CAMECA LEAP-HR systems located at CAES in Idaho Falls, USA (files beginning with R33), at Montanuniversität Leoben in Leoben, Austria (R21) and at Friedrich–Alexander University in Erlangen, Germany (R56).
Keywords: Dataset; Electron microscopy for materials research (EMAT)
DOI: 10.5281/ZENODO.3407832
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Samaeeaghmiyoni V, Cordier P, Demouchy S, Bollinger C, Gasc J, Mussi A, Schryvers D, Idrissi H (2020) Research data supporting for Stress-induced amorphization triggers deformation in the lithospheric mantle
Keywords: Dataset; Electron microscopy for materials research (EMAT)
DOI: 10.5281/zenodo.3893661
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Idrissi H, Samaee V, Lumbeeck G, van der Werf T, Pardoen T, Schryvers D, Cordier P (2019) Supporting data for “In situ Quantitative Tensile Tests on Antigorite in a Transmission Electron Microscope”
Abstract: The determination of the mechanical properties of serpentinites is essential towards the understanding of the mechanics of faulting and subduction. Here, we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push-to-pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the microstructure is imaged with the microscope. The experiments have been performed at room temperature on beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that some grains were well-oriented for plastic slip. However, no dislocation activity has been observed even though engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit an pure elastic-brittle behaviour since, despite the presence of defects, the specimens underwent plastic deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under our experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates.
Keywords: Dataset; Electron microscopy for materials research (EMAT)
DOI: 10.5281/ZENODO.3583135
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“Application of atmospheric plasma-jets for the conservation of cultural heritage”. Grieten E, Storme P, Caen J, Schalm O, Schryvers D, (2015)
Keywords: P3 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Antwerp Cultural Heritage Sciences (ARCHES)
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“3D FIB/SEM study of Ni4Ti3 precipitates in Ni-Ti alloys with different thermal-mechanical histories”. Cao S, Nishida M, Somsen C, Eggeler G, Schryvers D, , 02004 (2009). http://doi.org/10.1051/esomat/200902004
Abstract: The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates growing in binary Ni-rich Ni-Ti alloys have been investigated via a slice view procedure in a Dual-Beam FIB/SEM system, in order to better stress-free Ni50.8Ti49.2 alloy with all four variants of precipitates and a compressed Ni51Ti49 alloy with aligned precipitates in one family were studied. The Ni4Ti3 precipitates reach a volume fraction of 9.6% in the reconstructed region of the stress-free alloy and 4.3% in the compressed one. In both cases, the mean volume, specific surface area, sphericity and aspect ratio of the precipitates are calculated and the Pair Distribution Functions of the precipitates are obtained. It is shown that most precipitates in the stress-free sample grow larger and have a more lenticular shape, while those in the compressed sample are more cylindrical. Deviations from these ideal shapes reveal internal steps in the stress-free sample and lamellae formation in the compressed one.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.1051/esomat/200902004
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“3D strain fields surrounding Ni4Ti3: direct measurement and correlation with the R-phase”. Tirry W, Schryvers D, , 02032 (2009). http://doi.org/10.1051/esomat/200902032
Abstract: Strain fields introduced by coherent Ni4Ti3 precipitates in austenitic Ni-Ti are believed to be a possible origin of why the R-phase transformation is introduced as an extra step before transforming to the B19'. The presence of this strain field was already confirmed in the past by conventional transmission electron microscopy (TEM) techniques and measured quantitatively by high resolution TEM (HRTEM). This time the geometrical phase method is applied on HRTEM micrographs to measure the full 3D strain tensor of the strain fields. Since each atomic resolution micrograph only results in a 2D measurement of the strain, observations in two different zone orientations are combined to retrieve the 3 x 3 strain tensor. In this work observations in a [1-1 1](B2) and [1 0-1](B2) zone orientation are used and this in case of precipitates with a diameter of around 50nm. In a next step the measured strain tensor is compared to the calculated eigenstrain of the R-phase in reference to the B2 matrix. This comparison shows that the introduced strain is very similar to the eigenstrain of one R-phase variant. Since for both structures, Ni4Ti3 and R-phase, four orientation variants are possible, each variant of the R-phase is thus able to accommodate the strain field of one of the Ni4Ti3 variants.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
DOI: 10.1051/esomat/200902032
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“Investigation of Ag, Ag2S and Ag(Br,I) small particles by HREM and AEM”. Oleshko V, Schryvers D, Gijbels R, Jacob W s.l., page 293 (1998).
Keywords: H3 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Pinning of the martensitic microstructures by dislocations in Cu74.08Al23.13Be2.79”. Idrissi H, Schryvers D, Salje EKH, Zhang H, Carpenter MA, Moya X, , 02029 (2009). http://doi.org/10.1051/esomat/200902029
Abstract: A single crystal of Cu74.08Al23.13Be2.79 undergoes a martensitic phase transition at 246K and 232K under heating and cooling, respectively. Surprisingly, the martensite phase is elastically much harder than the austenite phase showing that interfaces between various crystallographic variants are strongly pinned and can not be moved by external stress while the phase boundary between the austenite and martensite regions in the sample remains mobile. This unusual behavior was revealed by Dynamical Mechanical Analysis and Resonant Ultrasound Spectroscopy. Transmission Electron Microscopy shows that the pinning is generated by dislocations, which are inherited from the austenite phase. Such dislocations can hinder the movement of stacking faults in the 18R martensite structure or twin boundaries between martensite variants.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 2
DOI: 10.1051/esomat/200902029
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“TEM study of the mechanism of Ni ion release from Nitinol wires with original oxides”. Tian H, Schryvers D, Shabalovskaya S, van Humbeeck J, , 05027 (2009). http://doi.org/10.1051/esomat/200905027
Abstract: The surface of commercial Nitinol wires with original oxides and a thickness in the 30-190 nm range was investigated by different state of art TEM techniques. The oxide surface layer was identified as a combination of TiO and TiO2 depending on the processing of the wire. Between the core of the wires and the oxidized surface, an interfacial Ni3Ti nanolayer was observed while Ni nanoparticles are found inside the original oxide. The particle sizes, their distribution in the surface and the Ti-O stoichiometry were deduced from the analysis of the obtained data. Molecular dynamics calculations performed for evaluation of the stability of Ni particles relative to the atomic state revealed that a pure Ni particle has a lower energy than free Ni atoms inside the TiO2 lattice. The obtained results are discussed with respect to surface stability and Ni release in the human body.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.1051/esomat/200905027
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“Transmission electron microscopy study of low-hysteresis shape memory alloys”. Delville R, James RD, Salman U, Finel A, Schryvers D, , 02005 (2009). http://doi.org/10.1051/esomat/200902005
Abstract: Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50-xPdx where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The atomically sharp, defect free, low energy configuration of the interface suggests that it plays an important role in the lowering of hysteresis. Finally, dynamical modeling of the martensitic transformation using the phase-field micro-elasticity model within the geometrically linear theory succeeded in reproducing the change in microstructure as the compatibility condition is satisfied. Latest results on the extension of these findings in other Ni-Ti based ternary/quaternary systems are also reported.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 3
DOI: 10.1051/esomat/200902005
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“Electron microscopy study of twinning in the Ni5Al3 bainitic phase”. Schryvers D, Ma Y, Toth L, Tanner L, TMS (1994)
Abstract: This contribution describes conventional and high resolution electron microscopy results on the different twinning arrangements in NisAl3 precipitates grown inside the B2 austenite phase. Short annealings introduce self-accommodating three-pointed star shaped precipitates consisting of twin related parts of different variants of the NisAl3 structure. Longer annealings result in plates growing separately from these wings and developing microtwinning in order to accommodate stress built-up at the interfaces with the surrounding matrix.
Keywords: A3 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
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“Electron microscopy study of twin sequences and branching in NissAl34 3R martensite”. Schryvers D, Van Landuyt J, ICOMAT (1992)
Abstract: Microtwin sequences in Ni66Al34 martensite plates of different size were investigated by electron microscopy. Although mostly irregular sequences were observed an average twin width w can be determined which increases with twin length L following the expected relation w ~ sqrt(L). High resolution electron microscopy was used to study the twin branching close to the plate boundaries and an atomic model for the branching of a microtwin and the changes in twin thickness is suggested
Keywords: A3 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
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“Firsto order phase transformation in the Ni-Al system”. Tanner LE, Shapiro SM, Krumhansl JA, Schryvers D, Noda Y, Yamada Y, Barsch GR, Gooding R, Moss SC, Metallurgy and Ceramics (1992)
Abstract: First-order displacive phase transformations in alloys and compounds are of high technological importance. We have studied this class of phase transformation in the high-temperature-stable Ni-Al f32(B2) phase as a function of composition, temperature, and stress using transmission electron microscopy and neutron scattering. The results show in detail the direct relationship between the unusually low energies of the transformation-related phonon modes and the development of pre-transformation microstructures (strain-embryos, etc.) via anharmonic coupling processes that ultimately lead to the nucleation and growth of the low-temperature martensitic phases. With these results, it is now possible to develop effective models for nonclassical heterogeneous nucleation of martensite transformations in bulk materials. This tills a critical gap and sets the stage for us to proceed in developing a more global understanding of condensed matter transformations including the coupling of displacive with replacive mechanisms.
Keywords: A3 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
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“On the phase-like nature of the 7M structure in Ni-Al”. Schryvers D, Tanner LE, Ecomaterials , 849 (1994). http://doi.org/10.1016/B978-1-4832-8381-4.50198-0
Abstract: The existence of the (52) stacking of the 7M martensite structure in Ni-Al is discussed in view of different experimental observations relating this structure to the premartensitic anomalies. It is concluded that the extreme fineness of the twinning is inherited from the wavelength of the premartensitic anomalies, while, given this dimension, the actual stacking tries to comply with stress free habit plane conditions by choosing the specific (52) stacking.
Keywords: A3 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
DOI: 10.1016/B978-1-4832-8381-4.50198-0
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“Analysis of internal stress build-up during deposition of nanocrystalline Ni thin films using transmission electron microscopy”. Lumbeeck G, Delvaux A, Idrissi H, Proost J, Schryvers D, Thin solid films : an international journal on the science and technology of thin and thick films 707, 138076 (2020). http://doi.org/10.1016/j.tsf.2020.138076
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.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1016/j.tsf.2020.138076
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“Experimental studies on precursor phenomena in displacive phase transformations”. Schryvers D, Properties Of Complex Inorganic Solids , 321 (1997)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
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“On the phase-like nature of the 7m structure in ni-al”. Schryvers D, Tanner LE, , 849 (1994)
Keywords: P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Times cited: 1
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“Electron microscopy study of ternary precipitates in Ni39.6Mn47.5Ti12.9”. Seo JW, Schryvers D, Potapov P, , 17 (1998)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“Positron annihilation study of nanocrystalline Ni3Al : simulations and measurements”. Kuriplach J, van Petegem S, Hou M, Van Tendeloo G, Schryvers D, et al, Materials science forum
T2 –, 12th International Conference on Positron Annihilation (ICPA-12), AUG 06-12, 2000, UNIV BUNDERSWEHR MUNCHEN, NEUBIBERG, GERMANY 363-3, 94 (2001)
Abstract: A positron lifetime experiment is performed on samples produced by the compaction of nanocrystalline Ni3Al powder synthesized by the inert-gas condensation technique. In the lifetime spectrum we observe two components corresponding to defects. Computer (virtual) samples of n-Ni3Al are obtained using molecular dynamics combined with the Metropolis Monte Carlo technique. Positron lifetime calculations are then performed on selected regions of simulated samples. For this purpose, a new computational technique based on a generalization of the atomic superposition method for non-periodic systems was developed. Lifetimes calculated in this way are compared to experiment.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Defect induced thickness growth in silver chloride (111) tabular crystals: a TEM study”. Van Renterghem W, Schryvers D, van Landuyt J, Bollen D, Van Roost C, De Keyzer RB, , 38 (2000)
Abstract: Defects in AgG tabular crystals with {111} surfaces are characterised by transmission electron microscopy (TEM) and their influence on the growth process is discussed. In the tabular crystals, twins parallel to the tabular face as well as dislocations along different directions are observed. The twins induce the tabular growth, while the dislocations do not influence the morphology. In 10 to 30% of the crystals that have been characterised, thickness growth is observed and it is shown that in all cases twins on other planes than the tabular ones are present. Two configurations occur more frequently and are analysed in detail. For the first group, twins parallel to the tabular face as well as a microtwin along a non-parallel {111} plane and ending inside the crystal are present. In the crystals of the second group only one extra non-parallel twin occurs giving rise to a bicrystal built up by a tetrahedral shaped part and a flat triangular or trapezoidal part. More complex twin configurations give rise to various, less characteristic morphologies.
Keywords: P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
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“The influence of the precipitation method on defect formation in multishell AgBrI (111) tabular crystals”. Van Renterghem W, Karthauser S, Schryvers D, van Landuyt J, De Keyzer R, Van Roost C, , 167 (2000)
Abstract: Multishell tabular grains have a higher speed than pure AgBr tabular grains. Usually the shells differ in size and iodide content, but also the precipitation method for the iodide containing shells has an influence on the iodide incorporation. A TEM investigation was performed to determine the defect structure of multishell AgBr (111) tabular crystals containing a shell with a low iodide concentration and one with a high iodide concentration. The twins that induce tabular growth and stacking fault contrast in the region of the iodide shells have been observed, similar to previously studied AgBr/Ag(Br,I) coreshell crystals. Moreover in some of the crystals dislocations have been observed, sometimes even an entire network. The number of dislocations formed varies for the different methods of iodide addition. Also variations in average thickness between the different iodide addition methods have been observed. A higher number of dislocations and thicker crystals point towards a higher local concentration of iodide. These observations allow deciding which iodide incorporation method is most useful for a preferred dislocation pattern.
Keywords: P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
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“Two generations of exsolution lamellae in pyroxene from Asuka 09545 : Clues to the thermal evolution of silicates in mesosiderite”. Pittarello L, Mckibbin S, Yamaguchi A, Ji G, Schryvers D, Debaille V, Claeys P, The American mineralogist 104, 1663 (2019). http://doi.org/10.2138/AM-2019-7001
Abstract: Mesosiderite meteorites consist of a mixture of crustal basaltic or gabbroic material and metal. Their formation process is still debated due to their unexpected combination of crust and core materials, possibly derived from the same planetesimal parent body, and lacking an intervening mantle component. Mesosiderites have experienced an extremely slow cooling rate from ca. 550 degrees C, as recorded in the metal (0.25-0.5 degrees C/Ma). Here we present a detailed investigation of exsolution features in pyroxene from the Antarctic mesosiderite Asuka (A) 09545. Geothermobarometry calculations, lattice parameters, lamellae orientation, and the presence of clinoenstatite as the host were used in an attempt to constrain the evolution of pyroxene from 1150 to 570 degrees C and the formation of two generations of exsolution lamellae. After pigeonite crystallization at ca. 1150 degrees C, the first exsolution process generated the thick augite lamellae along (100) in the temperature interval 1000-900 degrees C. By further cooling, a second order of exsolution lamellae formed within augite along (001), consisting of monoclinic low-Ca pyroxene, equilibrated in the temperature range 900-800 degrees C. The last process, occurring in the 600-500 degrees C temperature range, was likely the inversion of high to low pigeonite in the host crystal, lacking evidence for nucleation of orthopyroxene. The formation of two generations of exsolution lamellae, as well as of likely metastable pigeonite, suggest non-equilibrium conditions. Cooling was sufficiently slow to allow the formation of the lamellae, their preservation, and the transition from high to low pigeonite. In addition, the preservation of such fine-grained lamellae limits long-lasting, impact reheating to a peak temperature lower than 570 degrees C. These features, including the presence of monoclinic low-Ca pyroxene as the host, are reported in only a few mesosiderites. This suggests a possibly different origin and thermal history from most mesosiderites and that the crystallography (i.e., space group) of low-Ca pyroxene could be used as parameter to distinguish mesosiderite populations based on their cooling history.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.021
DOI: 10.2138/AM-2019-7001
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