|
“Short-range layered A-site ordering in double perovskites NaLaBB'O6 (B = Mn, Fe, B' = Nb, Ta)”. Dachraoui W, Yang T, Liu C, Ling G, Hadermann J, Van Tendeloo G, Llobet A, Greenblatt M, Chemistry of materials 23, 2398 (2011). http://doi.org/10.1021/cm200226u
Abstract: The new compounds NaLaFeTaO6, NaLaFeNbO6, NaLaMnTaO6, and NaLaMnNbO6 have been synthesized and characterized with a combination of transmission electron microscopy, X-ray powder diffraction (XRPD), neutron powder diffraction (NPD), and magnetization measurements. Through electron microscopy study, a local layered order of the A-cations has been detected without the typical occurrence of rock salt order at the B-cation site. Satellite reflections in the electron diffraction related to the local layered order are not visible on the XRPD or NPD patterns. The occurrence of local layered order is supported by pair distribution function analysis, which also reveals the presence of uncorrelated displacements of the Nb and Ta cations. The octahedra are tilted according to the system a−b+a−, and the coordinates were refined from XRPD and NPD with a disordered cation distribution in the space group Pnma. The magnetic exchange interactions in NaLaFeTaO6 and NaLaFeNbO6 are antiferromagnetic, while they are ferromagnetic in NaLaMnTaO6 and NaLaMnNbO6. Long-range magnetic ordering is not observed down to 4 K for any of the compositions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 14
DOI: 10.1021/cm200226u
|
|
|
“Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite”. Dachraoui W, Hadermann J, Abakumov AM, Tsirlin AA, Batuk D, Glazyrin K, McCammon C, Dubrovinsky L, Van Tendeloo G, Chemistry of materials 24, 1378 (2012). http://doi.org/10.1021/cm300178x
Abstract: The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 27
DOI: 10.1021/cm300178x
|
|
|
“Perovskite transparent conducting oxides : an ab initio study”. Dabaghmanesh S, Saniz R, Amini MN, Lamoen D, Partoens B, Journal of physics : condensed matter 25, 415503 (2013). http://doi.org/10.1088/0953-8984/25/41/415503
Abstract: We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 me, and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.649
Times cited: 17
DOI: 10.1088/0953-8984/25/41/415503
|
|
|
“Casting light on the darkening of colors in historical paintings”. da Pieve F, Hogan C, Lamoen D, Verbeeck J, Vanmeert F, Radepont M, Cotte M, Janssens K, Gonze X, Van Tendeloo G, Physical review letters 111, 208302 (2013). http://doi.org/10.1103/PhysRevLett.111.208302
Abstract: The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify the composition of the damaged paint work and demonstrate possible physicochemical processes, induced by illumination and exposure to humidity and air, that cause photoactivation of the original pigment and the degradation of the secondary minerals. The results suggest a new path for the darkening process which was never considered by previous studies and prompt a critical examination of their findings.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.462
Times cited: 30
DOI: 10.1103/PhysRevLett.111.208302
|
|
|
“Origin of magnetism and quasiparticles properties in Cr-doped TiO2”. da Pieve F, Di Matteo S, Rangel T, Giantomassi M, Lamoen D, Rignanese G-M, Gonze X, Physical review letters 110, 136402 (2013). http://doi.org/10.1103/PhysRevLett.110.136402
Abstract: Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond density functional theory, we describe the magnetic ground state of Cr-doped TiO2, an intensively studied and debated dilute magnetic oxide. In parallel, we correct our LSDA+U (+ superexchange) ground state through GW corrections (GW@LSDA+U) that reproduce the position of the impurity states and the band gaps in satisfying agreement with experiments. Because of the different topological coordinations of Cr-Cr bonds in the ground states of rutile and anatase, superexchange interactions induce either ferromagnetic or antiferromagnetic couplings of Cr ions. In Cr-doped anatase, this interaction leads to a new mechanism which stabilizes a (nonrobust) ferromagnetic ground state, in keeping with experimental evidence, without the need to invoke F-center exchange. The interplay between structural defects and vacancies in contributing to the superexchange is also unveiled.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.462
Times cited: 15
DOI: 10.1103/PhysRevLett.110.136402
|
|
|
“Tuning of PCDTBT : PC71BM blend nanoparticles for eco-friendly processing of polymer solar cells”. D'Olieslaeger L, Pfannmöller M, Fron E, Cardinaletti I, Van der Auweraer M, Van Tendeloo G, Bals S, Maes W, Vanderzande D, Manca J, Ethirajan A, Solar energy materials and solar cells 159, 179 (2017). http://doi.org/10.1016/J.SOLMAT.2016.09.008
Abstract: We report the controlled preparation of water processable nanoparticles (NPs) employing the push-pull polymer PCDTBT and the fullerene acceptor PC71BM in order to enable solar cell processing using eco-friendly solvent (i.e. water). The presented method provides the possibility to separate the formation of the active layer blend and the deposition of the active layer into two different processes. For the first time, the benefits of aqueous processability for the high-potential class of push-pull polymers, generally requiring high boiling solvents, are made accessible. With our method we demonstrate excellent control over the blend stoichiometry and efficient mixing. Furthermore, we provide visualization of the nano morphology of the different NPs to obtain structural information down to similar to 2 nm resolution using advanced analytical electron microscopy. The imaging directly reveals very small compositional demixing in the PCDTBT:PC71BM blend NPs, in the size range of about <5 nm, indicating fine mixing at the molecular level. The suitability of the proposed methodology and materials towards the aspects of eco-friendly processing of organic solar cells is demonstrated through a processing of lab scale NPs solar cell prototypes reaching a power conversion efficiency of 1.9%. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.784
Times cited: 32
DOI: 10.1016/J.SOLMAT.2016.09.008
|
|
|
“Synthesis, crystal structure and magnetic properties of the Sr2Al0.78Mn1.22O5.2 anion-deficient layered perovskite”. d' Hondt H, Hadermann J, Abakumov AM, Kalyuzhnaya AS, Rozova MG, Tsirlin AA, Tan H, Verbeeck J, Antipov EV, Van Tendeloo G, Journal of solid state chemistry 182, 356 (2009). http://doi.org/10.1016/j.jssc.2008.11.002
Abstract: A new layered perovskite Sr2Al0.78Mn1.22O5.2 has been synthesized by solid state reaction in a sealed evacuated silica tube. The crystal structure has been determined using electron diffraction, high-resolution electron microscopy, and high-angle annular dark field imaging and refined from X-ray powder diffraction data (space group P4/mmm, a=3.89023(5) Å, c=7.8034(1) Å, RI=0.023, RP=0.015). The structure is characterized by an alternation of MnO2 and (Al0.78Mn0.22)O1.2 layers. Oxygen atoms and vacancies, as well as the Al and Mn atoms in the (Al0.78Mn0.22)O1.2 layers are disordered. The local atomic arrangement in these layers is suggested to consist of short fragments of brownmillerite-type tetrahedral chains of corner-sharing AlO4 tetrahedra interrupted by MnO6 octahedra, at which the chain fragments rotate over 90°. This results in an averaged tetragonal symmetry. This is confirmed by the valence state of Mn measured by EELS. The relationship between the Sr2Al0.78Mn1.22O5.2 tetragonal perovskite and the parent Sr2Al1.07Mn0.93O5 brownmillerite is discussed. Magnetic susceptibility measurements indicate spin glass behavior of Sr2Al0.78Mn1.22O5.2. The lack of long-range magnetic ordering contrasts with Mn-containing brownmillerites and is likely caused by the frustration of interlayer interactions due to presence of the Mn atoms in the (Al0.78Mn0.22)O1.2 layers.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 12
DOI: 10.1016/j.jssc.2008.11.002
|
|
|
“Tetrahedral chain order in the Sr2Fe2O5 brownmillerite”. d' Hondt H, Abakumov AM, Hadermann J, Kalyuzhnaya AS, Rozova MG, Antipov EV, Van Tendeloo G, Chemistry of materials 20, 7188 (2008). http://doi.org/10.1021/cm801723b
Abstract: The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 64
DOI: 10.1021/cm801723b
|
|
|
d' Hondt H (2011) Characterization of anion deficient perovskites. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
|
|
|
“Study of the thermal decomposition of melt-quenched Ni-rich metastable bcc and amorphous Ni-Zr alloys”. Cziraki A, Gerocs I, Fogarassy B, Van Tendeloo G, Sommer F, Bakonyi I, International journal of non-equilibrium processing 10, 265 (1998)
Abstract: The phase transformation sequences during thermal decomposition are investigated for Ni-rich melt-quenched body-centred cubic (bcc) and amorphous Ni-Zr alloys. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) are used to determine the structure of crystallization products occurring after heating the melt-spun ribbon samples to various degrees of the phase transformation process monitored by differential scanning calorimetry (DSC). A single DSC peak is observed for both the bcc and amorphous Ni(91)Zr(9) alloys and a two-step process is indicated by DSC for the amorphous Ni(90)Zr(10) alloy. In the bcc-Ni(91)Zr(9) alloy which is actually a Ni(Zr) solid solution phase, the phase transformation starts with the precipitation of Ni(5)Zr crystallites followed, after a sufficient depletion of the matrix in Zr, by the subsequent transformation of the bcc-Ni(Zr) lattice to face-centred cubic (fcc) Ni. In the amorphous alloy of the same composition, the final products are fcc-Ni and Ni(5)Zr but at intermediate stages of the phase transformation, bcc-Ni(Zr) crystallites also appear. In the a-Ni(90)Zr(10) alloy the first DSC peak corresponds to the formation of the bcc-Ni(Zr) phase which then decomposes (second DSC peak) to the equilibrium phases fcc-Ni and Ni(5)Zr. Thus, in addition to the previous observation of the formation of the metastable bcc-Ni(Zr) phase by rapid quenching from the melt, here we present evidence that this phase can form also after partial crystallization of metallic glasses of appropriate chemical compositions.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Times cited: 2
|
|
|
“Electron microscopy and X-ray diffraction studies of rapidly quenched Zr-Ni an Hf-Ni ribbons with about 90 at.% Ni”. Cziraki A, Fogarassy F, Van Tendeloo G, Lamparter P, Tegze M, Bakonyi I, Journal of alloys and compounds 210, 135 (1994). http://doi.org/10.1016/0925-8388(94)90128-7
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.999
Times cited: 26
DOI: 10.1016/0925-8388(94)90128-7
|
|
|
“Self-assembled epitaxial cathode-electrolyte nanocomposites for 3D microbatteries”. Cunha DM, Gauquelin N, Xia R, Verbeeck J, Huijben M, ACS applied materials and interfaces 14, 42208 (2022). http://doi.org/10.1021/ACSAMI.2C09474
Abstract: The downscaling of electronic devices requires rechargeable microbatteries with enhanced energy and power densities. Here, we evaluate self-assembled vertically aligned nano-composite (VAN) thin films as a platform to create high-performance three-dimensional (3D) microelectrodes. This study focuses on controlling the VAN formation to enable interface engineering between the LiMn2O4 cathode and the (Li,La)TiO3 solid electrolyte. Electrochemical analysis in a half cell against lithium metal showed the absence of sharp redox peaks due to the confinement in the electrode pillars at the nanoscale. The (100)-oriented VAN thin films showed better rate capability and stability during extensive cycling due to the better alignment to the Li-diffusion channels. However, an enhanced pseudocapacitive contribution was observed for the increased total surface area within the (110)-oriented VAN thin films. These results demonstrate for the first time the electrochemical behavior of cathode-electrolyte VANs for lithium-ion 3D microbatteries while pointing out the importance of control over the vertical interfaces.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 9.5
Times cited: 4
DOI: 10.1021/ACSAMI.2C09474
|
|
|
“Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps”. Cui W, Lin W, Lu W, Liu C, Gao Z, Ma H, Zhao W, Van Tendeloo G, Zhao W, Zhang Q, Sang X, Nature communications 14, 554 (2023). http://doi.org/10.1038/S41467-023-35972-9
Abstract: Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 16.6
DOI: 10.1038/S41467-023-35972-9
|
|
|
“Atomic defects, functional groups and properties in MXenes”. Cui W, Hu Z-Y, Unocic RR, Van Tendeloo G, Sang X, Chinese Chemical Letters 32, 339 (2021). http://doi.org/10.1016/J.CCLET.2020.04.024
Abstract: MXenes, a new family of functional two-dimensional (2D) materials, have shown great potential for an extensive variety of applications within the last decade. Atomic defects and functional groups in MXenes are known to have a tremendous influence on the functional properties. In this review, we focus on recent progress in the characterization of atomic defects and functional group chemistry in MXenes, and how to control them to directly influence various properties (e.g., electron transport, Li' adsorption, hydrogen evolution reaction (HER) activity, and magnetism) of 2D MXenes materials. Dynamic structural transformations such as oxidation and growth induced by atomic defects in MXenes are also discussed. The review thus provides perspectives on property optimization through atomic defect engineering, and bottom-up synthesis methods based on defect-assisted homoepitaxial growth of MXenes. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.932
DOI: 10.1016/J.CCLET.2020.04.024
|
|
|
“A framework to account for sedimentation and diffusion in particle-cell interactions”. Cui J, Faria M, Bjornmalm M, Ju Y, Suma T, Gunawan ST, Richardson JJ, Heidar H, Bals S, Crampin EJ, Caruso F, Langmuir: the ACS journal of surfaces and colloids 32, 12394 (2016). http://doi.org/10.1021/ACS.LANGMUIR.6B01634
Abstract: In vitro experiments provide a solid basis for understanding the interactions between particles and biological systems. An important confounding variable for these studies is the difference between the amount of particles administered and that which reaches the surface of cells. Here, we engineer a hydrogel-based nanoparticle system and combine in situ characterization techniques, 3D-printed cell cultures, and computational modeling to evaluate and study particle cell interactions of advanced particle systems. The framework presented demonstrates how sedimentation and diffusion can explain differences in particle cell association, and provides a means to account for these effects. Finally, using in silico modeling, we predict the proportion of particles that reaches the cell surface using common experimental conditions for a wide range of inorganic and organic micro- and nanoparticles. This work can assist in the understanding and control of sedimentation and diffusion when investigating cellular interactions of engineered particles.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.833
Times cited: 40
DOI: 10.1021/ACS.LANGMUIR.6B01634
|
|
|
“An efficient way of including thermal diffuse scattering in simulation of scanning transmission electron microscopic images”. Croitoru MD, van Dyck D, Van Aert S, Bals S, Verbeeck J, Ultramicroscopy 106, 933 (2006). http://doi.org/10.1016/j.ultramic.2006.04.006
Abstract: We propose an improved image simulation procedure for atomic-resolution annular dark-field scanning transmission electron microscopy (STEM) based on the multislice formulation, which takes thermal diffuse scattering fully into account. The improvement with regard to the classical frozen phonon approach is realized by separating the lattice configuration statistics from the dynamical scattering so as to avoid repetitive calculations. As an example, the influence of phonon scattering on the image contrast is calculated and investigated. STEM image simulation of crystals can be applied with reasonable computing times to problems involving a large number of atoms and thick or large supercells.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Vision lab
Impact Factor: 2.843
Times cited: 18
DOI: 10.1016/j.ultramic.2006.04.006
|
|
|
“Measurement of specimen thickness by phase change determination in TEM”. Croitoru MD, van Dyck D, Liu YZ, Zhang Z, Ultramicroscopy 108, 1616 (2008). http://doi.org/10.1016/j.ultramic.2008.06.002
Abstract: A non-destructive method for measuring the thickness of thin amorphous films composed of light elements has been developed. The method employs the statistics of the phase of the electron exit wave function. The accuracy of this method has been checked numerically by the multislice method and compared with that based on the mean inner potential.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.843
Times cited: 2
DOI: 10.1016/j.ultramic.2008.06.002
|
|
|
“Dependence of superconducting properties on the size and shape of a nanoscale superconductor: from nanowire to film”. Croitoru MD, Shanenko AA, Peeters FM, Physical review : B : condensed matter and materials physics 76, 024511 (2007). http://doi.org/10.1103/PhysRevB.76.024511
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 54
DOI: 10.1103/PhysRevB.76.024511
|
|
|
“Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent”. Croitoru MD, Shanenko AA, Peeters FM, International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 –, 32nd International Workshop on Condensed Matter Theories, Aug 12-19, 2008, Loughborough Univ, Loughborough, England 23, 4257 (2009). http://doi.org/10.1142/S0217979209063419
Abstract: We study the effect of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We show that in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic field exhibits quantum-size oscillations with pronounced resonant enhancements.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 0.736
Times cited: 1
DOI: 10.1142/S0217979209063419
|
|
|
“Tuning the superconducting properties of nanomaterials”. Croitoru MD, Shanenko AA, Peeters FM Springer, Dordrecht, page 1 (2009).
Abstract: Electron continement and its effect on the superconducting-to-normal phase transition driven by a magentic field and/or a current is studied in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We find that in a parallel magneitc field and/or in the presence of a supercurrent the transition from the superconducting to the normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magentic field exhibits quantum-size oscillations with pronounced resonant enhancements as a function of the wire radius.
Keywords: H1 Book chapter; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
DOI: 10.1007/978-90-481-3120-4_1
|
|
|
“Superconducting nanowires: interplay of discrete transverse modes with supercurrent”. Croitoru MD, Shanenko AA, Kaun CC, Peeters FM, Physical review : B : solid state 80, 024513 (2009). http://doi.org/10.1103/PhysRevB.80.024513
Abstract: From a numerical solution of the Bogoliubov-de Gennes equations, we investigate an interplay of the transverse discrete modes with a longitudinal supercurrent in a metallic cylindrical superconducting nanowire. The superconductor-to-normal transition induced by a longitudinal superflow of electrons is found to occur as a cascade of jumps in the order parameter (supercurrent and superfluid density) as a function of the superfluid velocity for diameters d<1015 nm (for Al parameters) and sufficiently low temperatures T<0.30.4Tc, with Tc the critical temperature. When approaching Tc, the jumps are smoothed into steplike but continuous drops. A similar picture occurs for d>1520 nm. Only when the diameter exceeds 5070 nm the quantum-size cascades are fully washed out, and we arrive at the mesoscopic regime. Below this regime the critical current density jc exhibits the quantum-size oscillations with pronounced resonant enhancements: the smaller the diameter, the more significant is the enhancement. Thickness fluctuations of real samples will smooth out such oscillations into an overall growth of jc with decreasing nanowire diameter.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.80.024513
|
|
|
“Quantum transport in a nanosize double-gate metal-oxide-semiconductor field-effect transistor”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Magnus W, Schoenmaker W, Sorée B, Journal of applied physics 96, 2305 (2004). http://doi.org/10.1063/1.1767619
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 2.068
Times cited: 14
DOI: 10.1063/1.1767619
|
|
|
“Quantum transport in a nanosize silicon-on-insulator metal-oxide-semiconductor field effect transistor”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Magnus W, Schoenmaker W, Sorée B, Journal of applied physics 93, 1230 (2003). http://doi.org/10.1063/1.1533108
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 2.068
Times cited: 16
DOI: 10.1063/1.1533108
|
|
|
“Quantum transport in an ultra-thin SOI MOSFET: influence of the channel thickness on the I-V characteristics”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Magnus W, Schoenmaker W, Sorée B, Solid state communications 147, 31 (2008). http://doi.org/10.1016/j.ssc.2008.04.025
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 1.554
Times cited: 8
DOI: 10.1016/j.ssc.2008.04.025
|
|
|
“Electroluminescence spectra of an STM-tip-induced quantum dot”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Kemerink M, Koenraad PM, Sauthoff K, Wolter JH, Physica. E: Low-dimensional systems and nanostructures 21, 270 (2004). http://doi.org/10.1016/j.physe.2003.11.028
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 2.221
Times cited: 1
DOI: 10.1016/j.physe.2003.11.028
|
|
|
“Electroluminescence spectra of an STM-tip-induced quantum dot”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Kemerink M, Koenraad PM, Sauthoff K, Wolter JH, Physical review : B : condensed matter and materials physics 68, 195307 (2003). http://doi.org/10.1103/PhysRevB.68.195307
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 4
DOI: 10.1103/PhysRevB.68.195307
|
|
|
“Influence of the characteristics of the STM-tip on the electroluminescence spectra”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Kemerink M, Koenraad PM, Sauthoff K, Wolter JH, Physica. E: Low-dimensional systems and nanostructures 27, 13 (2005). http://doi.org/10.1016/j.physe.2004.10.002
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 2.221
DOI: 10.1016/j.physe.2004.10.002
|
|
|
“Phase transformation of superparamagnetic iron oxide nanoparticles via thermal annealing : implications for hyperthermia applications”. Crippa F, Rodriguez-Lorenzo L, Hua X, Goris B, Bals S, Garitaonandia JS, Balog S, Burnand D, Hirt AM, Haeni L, Lattuada M, Rothen-Rutishauser B, Petri-Fink A, ACS applied nano materials 2, 4462 (2019). http://doi.org/10.1021/ACSANM.9B00823
Abstract: Magnetic hyperthermia has the potential to play an important role in cancer therapy and its efficacy relies on the nanomaterials selected. Superparamagnetic iron oxide nanoparticles (SPIONs) are excellent candidates due to the ability of producing enough heat to kill tumor cells by thermal ablation. However, their heating properties depend strongly on crystalline structure and size, which may not be controlled and tuned during the synthetic process; therefore, a postprocessing is needed. We show how thermal annealing can be simultaneously coupled with ligand exchange to stabilize the SPIONs in polar solvents and to modify their crystal structure, which improves hyperthermia behavior. Using high-resolution transmission electron microscopy, X-ray diffraction, Mossbauer spectroscopy, vibrating sample magnetometry, and lock-in thermography, we systematically investigate the impact of size and ligand exchange procedure on crystallinity, their magnetism, and heating ability. We describe a valid and simple approach to optimize SPIONs for hyperthermia by carefully controlling the size, colloidal stability, and crystallinity.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Times cited: 18
DOI: 10.1021/ACSANM.9B00823
|
|
|
“Double modulation and microstructure of the thermoelectric misfit compound \left[Ca2-yLnyCu0.7+yCo1.3-yO4\right]\left[CoO2\right]b_{1/b2} (Ln = Pr, Y and 0\leq y\leq1/3)”. Créon N, Pérez O, Hadermann J, Klein Y, Hébert S, Hervieu M, Raveau B, Chemistry of materials 18, 5355 (2006). http://doi.org/10.1021/cm061163a
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 6
DOI: 10.1021/cm061163a
|
|
|
“Oxidation barrier of Cu and Fe powder by Atomic Layer Deposition”. Cremers V, Rampelberg G, Barhoum A, Walters P, Claes N, Oliveira TM de, Assche GV, Bals S, Dendooven J, Detavernier C, Surface and coatings technology 349, 1032 (2018). http://doi.org/10.1016/j.surfcoat.2018.06.048
Abstract: Atomic layer deposition (ALD) is a vapor based technique which allows to deposit uniform, conformal films with a thickness control at the atomic scale. In this research, Al 2 O 3 coatings were deposited on micrometer-sized Fe and Cu powder (particles) using the thermal trimethylaluminum (TMA)/ water (H 2 O) process in a rotary pump-type ALD reactor. Rotation of the powder during deposition was required to obtain a pinhole-free ALD coating. The protective nature of the coating was evaluated by quantifying its effectiveness in protecting the metal particles during oxidative annealing treatments. The Al 2 O 3 coated powders were annealed in ambient air while in-situ thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) data were acquired. The thermal stability of a series of Cu and Fe powder with different Al 2 O 3 thicknesses were determined with TGA. In both samples a clear shift in oxidation temperature is visible. For Cu and Fe powder coated with 25 nm Al 2 O 3 , we observed an increase of the oxidation temperature with 300-400°C. For the Cu powder a thin film of only 8 nm is required to obtain an initial increase in oxidation temperature of 200°C. In contrast, for Fe powder a thicker coating of 25 nm is required. In both cases, the oxidation temperature increases with increasing thickness of the Al 2 O 3 coating. These results illustrate that the Al 2 O 3 thin film, deposited by the thermal ALD process (TMA/H 2 O) can be an efficient and pinhole-free barrier layer for micrometer-sized powder particles, provided that the powder is properly agitated during the process to ensure sufficient vapour-solid interaction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 10
DOI: 10.1016/j.surfcoat.2018.06.048
|
|