“Antisite Disorder and Bond Valence Compensation in Li2FePO4F Cathode for Li-Ion Batteries”. Karakulina OM, Khasanova NR, Drozhzhin OA, Tsirlin AA, Hadermann J, Antipov EV, Abakumov AM, Chemistry Of Materials 28, 7578 (2016). http://doi.org/10.1021/acs.chemmater.6b03746
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 10
DOI: 10.1021/acs.chemmater.6b03746
|
“Crystal growth of the Nowotny chimney ladder phase Fe2Ge3 : exploring new Fe-based narrow-gap semiconductor with promising thermoelectric performance”. Verchenko VY, Wei Z, Tsirlin AA, Callaert C, Jesche A, Hadermann J, Dikarev EV, Shevelkov AV, Chemistry of materials 29, 9954 (2017). http://doi.org/10.1021/ACS.CHEMMATER.7B03300
Abstract: <script type='text/javascript'>document.write(unpmarked('A new synthetic approach based on chemical transport reactions has been introduced to obtain the Nowotny chimney ladder phase Fe2Ge3 in the form of single crystals and polycrystalline powders. The single crystals possess the stoichiometric composition and the commensurate chimney ladder structure of the Ru2Sn3 type in contrast to the polycrystalline samples that are characterized by a complex microstructure. In compliance with the 18-n electron counting rule formulated for T-E intermetallics, electronic structure calculations reveal a narrow-gap semiconducting behavior of Fe2Ge3 favorable for high thermoelectric performance. Measurements of transport and thermoelectric properties performed on the polycrystalline samples confirm the formation of a narrow band gap of similar to 30 meV and reveal high absolute values of the Seebeck coefficient at elevated temperatures. Low glass-like thermal conductivity is observed in a wide temperature range that might be caused by the underlying complex microstructure.'));
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 11
DOI: 10.1021/ACS.CHEMMATER.7B03300
|
“Self‐Assembly of Atomically Thin Chiral Copper Heterostructures Templated by Black Phosphorus”. Nerl HC, Pokle A, Jones L, Müller‐Caspary K, Bos KHW, Downing C, McCarthy EK, Gauquelin N, Ramasse QM, Lobato I, Daly D, Idrobo JC, Van Aert S, Van Tendeloo G, Sanvito S, Coleman JN, Cucinotta CS, Nicolosi V, Advanced functional materials 29, 1903120 (2019). http://doi.org/10.1002/adfm.201903120
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.124
Times cited: 1
DOI: 10.1002/adfm.201903120
|
“Tailoring vanadium dioxide film orientation using nanosheets : a combined microscopy, diffraction, transport, and soft X-ray in transmission study”. Tran Phong Le P, Hofhuis K, Rana A, Huijben M, Hilgenkamp H, Rijnders GAJHM, ten Elshof JE, Koster G, Gauquelin N, Lumbeeck G, Schuessler-Langeheine C, Popescu H, Fortuna F, Smit S, Verbeek XH, Araizi-Kanoutas G, Mishra S, Vaskivskyi I, Duerr HA, Golden MS, Advanced Functional Materials 30, 1900028 (2020). http://doi.org/10.1002/ADFM.201900028
Abstract: Vanadium dioxide (VO2) is a much-discussed material for oxide electronics and neuromorphic computing applications. Here, heteroepitaxy of VO2 is realized on top of oxide nanosheets that cover either the amorphous silicon dioxide surfaces of Si substrates or X-ray transparent silicon nitride membranes. The out-of-plane orientation of the VO2 thin films is controlled at will between (011)(M1)/(110)(R) and (-402)(M1)/(002)(R) by coating the bulk substrates with Ti0.87O2 and NbWO6 nanosheets, respectively, prior to VO2 growth. Temperature-dependent X-ray diffraction and automated crystal orientation mapping in microprobe transmission electron microscope mode (ACOM-TEM) characterize the high phase purity, the crystallographic and orientational properties of the VO2 films. Transport measurements and soft X-ray absorption in transmission are used to probe the VO2 metal-insulator transition, showing results of a quality equal to those from epitaxial films on bulk single-crystal substrates. Successful local manipulation of two different VO2 orientations on a single substrate is demonstrated using VO2 grown on lithographically patterned lines of Ti0.87O2 and NbWO6 nanosheets investigated by electron backscatter diffraction. Finally, the excellent suitability of these nanosheet-templated VO2 films for advanced lensless imaging of the metal-insulator transition using coherent soft X-rays is discussed.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19
Times cited: 1
DOI: 10.1002/ADFM.201900028
|
“Diluted oxide interfaces with tunable ground states”. Gan Y, Christensen DV, Zhang Y, Zhang H, Krishnan D, Zhong Z, Niu W, Carrad DJ, Norrman K, von Soosten M, Jespersen TS, Shen B, Gauquelin N, Verbeeck J, Sun J, Pryds N, Chen Y, Advanced materials 31, 1805970 (2019). http://doi.org/10.1002/ADMA.201805970
Abstract: The metallic interface between two oxide insulators, such as LaAlO3/SrTiO3 (LAO/STO), provides new opportunities for electronics and spintronics. However, due to the presence of multiple orbital populations, tailoring the interfacial properties such as the ground state and metal-insulator transitions remains challenging. Here, an unforeseen tunability of the phase diagram of LAO/STO is reported by alloying LAO with a ferromagnetic LaMnO3 insulator without forming lattice disorder and at the same time without changing the polarity of the system. By increasing the Mn-doping level, x, of LaAl1-xMnxO3/STO (0 <= x <= 1), the interface undergoes a Lifshitz transition at x = 0.225 across a critical carrier density of n(c) = 2.8 x 10(13) cm(-2), where a peak T-SC approximate to 255 mK of superconducting transition temperature is observed. Moreover, the LaAl1-xMnxO3 turns ferromagnetic at x >= 0.25. Remarkably, at x = 0.3, where the metallic interface is populated by only d(xy) electrons and just before it becomes insulating, a same device with both signatures of superconductivity and clear anomalous Hall effect (7.6 x 10(12) cm(-2) < n(s) <= 1.1 x 10(13) cm(-2)) is achieved reproducibly. This provides a unique and effective way to tailor oxide interfaces for designing on-demand electronic and spintronic devices.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 31
DOI: 10.1002/ADMA.201805970
|
“Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films”. Wang J, Shin Y, Gauquelin N, Yang Y, Lee C, Jannis D, Verbeeck J, Rondinelli JM, May SJ, Journal of physics : condensed matter 31, 365602 (2019). http://doi.org/10.1088/1361-648X/ab2414
Abstract: Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ = 0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 5
DOI: 10.1088/1361-648X/ab2414
|
“Unravelling stacking order in epitaxial bilayer MX₂, using 4D-STEM with unsupervised learning”. Mehta AN, Gauquelin N, Nord M, Orekhov A, Bender H, Cerbu D, Verbeeck J, Vandervorst W, Nanotechnology 31, 445702 (2020). http://doi.org/10.1088/1361-6528/ABA5B6
Abstract: Following an extensive investigation of various monolayer transition metal dichalcogenides (MX2), research interest has expanded to include multilayer systems. In bilayer MX2, the stacking order strongly impacts the local band structure as it dictates the local confinement and symmetry. Determination of stacking order in multilayer MX(2)domains usually relies on prior knowledge of in-plane orientations of constituent layers. This is only feasible in case of growth resulting in well-defined triangular domains and not useful in-case of closed layers with hexagonal or irregularly shaped islands. Stacking order can be discerned in the reciprocal space by measuring changes in diffraction peak intensities. Advances in detector technology allow fast acquisition of high-quality four-dimensional datasets which can later be processed to extract useful information such as thickness, orientation, twist and strain. Here, we use 4D scanning transmission electron microscopy combined with multislice diffraction simulations to unravel stacking order in epitaxially grown bilayer MoS2. Machine learning based data segmentation is employed to obtain useful statistics on grain orientation of monolayer and stacking in bilayer MoS2.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.5
Times cited: 13
DOI: 10.1088/1361-6528/ABA5B6
|
“Inhomogeneous superconductivity and quasilinear magnetoresistance at amorphous LaTiO₃/SrTiO₃, interfaces”. Lebedev N, Stehno M, Rana A, Gauquelin N, Verbeeck J, Brinkman A, Aarts J, Journal Of Physics-Condensed Matter 33, 055001 (2020). http://doi.org/10.1088/1361-648X/ABC102
Abstract: We have studied the transport properties of LaTiO3/SrTiO3 (LTO/STO) heterostructures. In spite of 2D growth observed in reflection high energy electron diffraction, transmission electron microscopy images revealed that the samples tend to amorphize. Still, we observe that the structures are conducting, and some of them exhibit high conductance and/or superconductivity. We established that conductivity arises mainly on the STO side of the interface, and shows all the signs of the two-dimensional electron gas usually observed at interfaces between STO and LTO or LaAlO3, including the presence of two electron bands and tunability with a gate voltage. Analysis of magnetoresistance (MR) and superconductivity indicates the presence of spatial fluctuations of the electronic properties in our samples. That can explain the observed quasilinear out-of-plane MR, as well as various features of the in-plane MR and the observed superconductivity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.7
Times cited: 1
DOI: 10.1088/1361-648X/ABC102
|
“Leaf area-length allometry and its implications in leaf shape evolution”. Shi P, Liu M, Ratkowsky DA, Gielis J, Su J, Yu X, Wang P, Zhang L, Lin Z, Schrader J, Trees: structure and function 33, 1073 (2019). http://doi.org/10.1007/S00468-019-01843-4
Abstract: According to Thompson’s principle of similarity, the area of an object should be proportional to its length squared. However, leaf area–length data of some plants have been demonstrated not to follow the principle of similarity. We explore the reasons why the leaf area–length allometry deviates from the principle of similarity and examine whether there is a general model describing the relationship among leaf area, width and length. We sampled more than 11,800 leaves from six classes of woody and herbaceous plants and tested the leaf area–length allometry. We compared six mathematical models based on root-mean-square error as the measure of goodness-of-fit. The best supported model described a proportional relationship between leaf area and the product of leaf width and length (i.e., the Montgomery model). We found that the extent to which the leaf area–length allometry deviates from the principle of similarity depends upon the extent of variation of the ratio of leaf width to length. Estimates of the parameter of the Montgomery model ranged between 1/2, which corresponds to a triangular leaf with leaf length as its height and leaf width as its base, and π/4, which corresponds to an elliptical leaf with leaf length as its major axis and leaf width as its minor axis, for the six classes of plants. The narrow range in practice of the Montgomery parameter implies an evolutionary stability for the leaf area of large-leaved plants despite the fact that leaf shapes of these plants are rather different.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1007/S00468-019-01843-4
|
“A comparison of floating-electrode DBD and kINPen jet : plasma parameters to achieve similar growth reduction in colon cancer cells under standardized conditions”. Bekeschus S, Lin A, Fridman A, Wende K, Weltmann K-D, Miller V, Plasma chemistry and plasma processing 38, 1 (2018). http://doi.org/10.1007/S11090-017-9845-3
Abstract: A comparative study of two plasma sources (floating-electrode dielectric barrier discharge, DBD, Drexel University; atmospheric pressure argon plasma jet, kINPen, INP Greifswald) on cancer cell toxicity was performed. Cell culture protocols, cytotoxicity assays, and procedures for assessment of hydrogen peroxide (H2O2) were standardized between both labs. The inhibitory concentration 50 (IC50) and its corresponding H2O2 deposition was determined for both devices. For the DBD, IC50 and H2O2 generation were largely dependent on the total energy input but not pulsing frequency, treatment time, or total number of cells. DBD cytotoxicity could not be replicated by addition of H2O2 alone and was inhibited by larger amounts of liquid present during the treatment. Jet plasma toxicity depended on peroxide generation as well as total cell number and amount of liquid. Thus, the amount of liquid present during plasma treatment in vitro is key in attenuating short-lived species or other physical effects from plasmas. These in vitro results suggest a role of liquids in or on tissues during plasma treatment in a clinical setting. Additionally, we provide a platform for correlation between different plasma sources for a predefined cellular response.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.355
Times cited: 12
DOI: 10.1007/S11090-017-9845-3
|
“Crystal structure and properties of the new complex vanadium oxide K2SrV3O9”. Tsirlin AA, Chernaya VV, Shpanchenko RV, Antipov EV, Hadermann J, Materials research bulletin 40, 800 (2005). http://doi.org/10.1016/j.materresbull.2005.02.004
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.446
Times cited: 9
DOI: 10.1016/j.materresbull.2005.02.004
|
“Oxygen-driven competition between low-dimensional structures of Sr3CoMO6 and Sr3CoMO7-\delta with M = Ru,Ir”. Mikhailova D, Reichel P, Tsirlin AA, Abakumov AM, Senyshyn A, Mogare KM, Schmidt M, Kuo CY, Pao CW, Pi TW, Lee JF, Hu Z, Tjeng LH;, Journal of the Chemical Society : Dalton transactions 43, 13883 (2014). http://doi.org/10.1039/c4dt01893a
Abstract: We have realized a reversible structure transformation of one-dimensional 1D K4CdCl6-type Sr3CoMO6 with the Co2+/M4+ cation ordering into the two-dimensional 2D double layered Ruddlesden-Popper structure Sr3CoMO7-delta with a random distribution of Co and M (with M = Ru, Ir) upon increasing the partial oxygen pressure. The combined soft and hard X-ray absorption spectroscopy studies show that under transformation, Co and M cations were oxidized to Co3+ and M5+. During oxidation, high-spin Co2+ in Sr3CoMO6 first transforms into high-spin Co3+ in oxygen-deficient Sr3CoMO7-delta, and then further transforms into low-spin Co3+ in fully oxidized Sr3CoMO7 upon further increasing the partial pressure of oxygen. The 1D Sr3CoMO6 compound is magnetically ordered at low temperatures with the magnetic moments lying along the c-axis. Their alignment is parallel for Sr3CoRuO6 and antiparallel for Sr3CoIrO6. The 2D compounds reveal a spin-glass-like behavior related to the random distribution of magnetic cations in the structure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
Times cited: 7
DOI: 10.1039/c4dt01893a
|
“Characterization of Non-Thermal Dielectric Barrier Discharges for Plasma Medicine: From Plastic Well Plates to Skin Surfaces”. Lin A, Gromov M, Nikiforov A, Smits E, Bogaerts A, Plasma Chemistry and Plasma Processing 43, 1587 (2023). http://doi.org/10.1007/s11090-023-10389-w
Abstract: technologies have been expanding, and one of the most exciting and rapidly growing
applications is in biology and medicine. Most biomedical studies with DBD plasma systems are performed in vitro, which include cells grown on the surface of plastic well plates, or in vivo, which include animal research models (e.g. mice, pigs). Since many DBD systems use the biological target as the secondary electrode for direct plasma generation and treatment, they are sensitive to the surface properties of the target, and thus can be altered based on the in vitro or in vivo system used. This could consequently affect biological response from plasma treatment. Therefore, in this study, we investigated the DBD plasma behavior both in vitro (i.e. 96-well flat bottom plates, 96-well U-bottom plates, and 24-well flat bottom plates), and in vivo (i.e. mouse skin). Intensified charge coupled device (ICCD) imaging was performed and the plasma discharges were visually distinguishable between the different systems. The geometry of the wells did not affect DBD plasma generation for low application distances (≤ 2 mm), but differentially affected plasma uniformity on the bottom of the well at greater distances. Since DBD plasma treatment in vitro is rarely performed in dry wells for plasma medicine experiments, the effect of well wetness was also investigated. In all in vitro cases, the uniformity of the DBD plasma was affected when comparing wet versus dry wells, with the plasma in the wide-bottom wells appearing the most similar to plasma generated on mouse skin. Interestingly, based on quantification of ICCD images, the DBD plasma intensity per surface area demonstrated an exponential one-phase decay with increasing application distance, regardless of the in vitro or in vivo system. This trend is similar to that of the energy per pulse of plasma, which is used to determine the total plasma treatment energy for biological systems. Optical emission spectroscopy performed on the plasma revealed similar trends in radical species generation between the plastic well plates and mouse skin. Therefore, taken together, DBD plasma intensity per surface area may be a valuable parameter to be used as a simple method for in situ monitoring during biological treatment and active plasma treatment control, which can be applied for in vitro and in vivo systems.
Keywords: A1 Journal Article; Non-thermal plasma · Plasma medicine · Dielectric barrier discharge · Plasma diagnostics · Plasma surface interaction · In situ plasma monitoring; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.6
DOI: 10.1007/s11090-023-10389-w
|
“Auranofin repurposing for lung and pancreatic cancer : low CA12 expression as a marker of sensitivity in patient-derived organoids, with potentiated efficacy by AKT inhibition”. Deben C, Freire Boullosa L, Rodrigues Fortes F, Cardenas De La Hoz E, Le Compte M, Seghers S, Peeters M, Vanlanduit S, Lin A, Dijkstra KK, Van Schil P, Hendriks JMH, Prenen H, Roeyen G, Lardon F, Smits E, Journal of Experimental and Clinical Cancer Research 43, 88 (2024). http://doi.org/10.1186/S13046-024-03012-Z
Abstract: Background This study explores the repurposing of Auranofin (AF), an anti-rheumatic drug, for treating non-small cell lung cancer (NSCLC) adenocarcinoma and pancreatic ductal adenocarcinoma (PDAC). Drug repurposing in oncology offers a cost-effective and time-efficient approach to developing new cancer therapies. Our research focuses on evaluating AF's selective cytotoxicity against cancer cells, identifying RNAseq-based biomarkers to predict AF response, and finding the most effective co-therapeutic agents for combination with AF. Methods Our investigation employed a comprehensive drug screening of AF in combination with eleven anticancer agents in cancerous PDAC and NSCLC patient-derived organoids (n = 7), and non-cancerous pulmonary organoids (n = 2). Additionally, we conducted RNA sequencing to identify potential biomarkers for AF sensitivity and experimented with various drug combinations to optimize AF's therapeutic efficacy. Results The results revealed that AF demonstrates a preferential cytotoxic effect on NSCLC and PDAC cancer cells at clinically relevant concentrations below 1 µM, sparing normal epithelial cells. We identified Carbonic Anhydrase 12 (CA12) as a significant RNAseq-based biomarker, closely associated with the NF-κB survival signaling pathway, which is crucial in cancer cell response to oxidative stress. Our findings suggest that cancer cells with low CA12 expression are more susceptible to AF treatment. Furthermore, the combination of AF with the AKT inhibitor MK2206 was found to be particularly effective, exhibiting potent and selective cytotoxic synergy, especially in tumor organoid models classified as intermediate responders to AF, without adverse effects on healthy organoids. Conclusion Our research offers valuable insights into the use of AF for treating NSCLC and PDAC. It highlights AF's cancer cell selectivity, establishes CA12 as a predictive biomarker for AF sensitivity, and underscores the enhanced efficacy of AF when combined with MK2206 and other therapeutics. These findings pave the way for further exploration of AF in cancer treatment, particularly in identifying patient populations most likely to benefit from its use and in optimizing combination therapies for improved patient outcomes.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Center for Oncological Research (CORE)
DOI: 10.1186/S13046-024-03012-Z
|
“{110}-Layered B-cation ordering in the anion-deficient perovskite Pb2.4Ba2.6Fe2Sc2TiO13 with the crystallographic shear structure”. Tyablikov OA, Batuk D, Tsirlin AA, Batuk M, Verchenko VY, Filimonov DS, Pokholok KV, Sheptyakov DV, Rozova MG, Hadermann J, Antipov EV, Abakumov AM;, Journal of the Chemical Society : Dalton transactions 44, 10753 (2015). http://doi.org/10.1039/c4dt03867c
Abstract: A novel anion-deficient perovskite-based compound, Pb2.4Ba2.6Fe2Sc2TiO13, was synthesized via the citrate-based route. This compound is an n = 5 member of the A(n)B(n)O(3n-2) homologous series with unit-cell parameters related to the perovskite subcell a(p) approximate to 4.0 angstrom as a(p)root 2 x a(p) x 5a(p)root 2. The crystal structure of Pb2.4Ba2.6Fe2Sc2TiO13 consists of quasi-2D perovskite blocks with a thickness of three octahedral layers separated by the 1/2[110]((1) over bar 01)(p) crystallographic shear (CS) planes, which are parallel to the {110} plane of the perovskite subcell. The CS planes transform the corner-sharing octahedra into chains of edge-sharing distorted tetragonal pyramids. Using a combination of neutron powder diffraction, Fe-57 Mossbauer spectroscopy and atomic resolution electron energy-loss spectroscopy we demonstrate that the B-cations in Pb2.4Ba2.6Fe2Sc2TiO13 are ordered along the {110} perovskite layers with Fe3+ in distorted tetragonal pyramids along the CS planes, Ti4+ preferentially in the central octahedra of the perovskite blocks and Sc3+ in the outer octahedra of the perovskite blocks. Magnetic susceptibility and Mossbauer spectroscopy indicate a broadened magnetic transition around T-N similar to 45 K and the onset of local magnetic fields at low temperatures. The magnetic order is probably reminiscent of that in other A(n)B(n)O(3n-2) homologues, where G-type AFM order within the perovskite blocks has been observed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
Times cited: 1
DOI: 10.1039/c4dt03867c
|
“Direct-synthesis method towards copper-containing periodic mesoporous organosilicas : detailed investigation of the copper distribution in the material”. Lin F, Meng, Kukueva E, Altantzis T, Mertens M, Bals S, Cool P, Van Doorslaer S, Journal of the Chemical Society : Dalton transactions 44, 9970 (2015). http://doi.org/10.1039/c4dt03719g
Abstract: Three-dimensional cubic Fm (3) over barm mesoporous copper-containing ethane-bridged PMO materials have been prepared through a direct-synthesis method at room temperature in the presence of cetyltrimethylammonium bromide as surfactant. The obtained materials have been unambiguously characterized in detail by several sophisticated techniques, including XRD, UV-Vis-Dr, TEM, elemental mapping, continuous- wave and pulsed EPR spectroscopy. The results show that at lower copper loading, the Cu2+ species are well dispersed in the Cu-PMO materials, and mainly exist as mononuclear Cu2+ species. At higher copper loading amount, Cu2+ clusters are observed in the materials, but the distribution of the Cu2+ species is still much better in the Cu-PMO materials prepared through the direct-synthesis method than in a Cu-containing PMO material prepared through an impregnation method. Moreover, the evolution of the copper incorporation during the PMO synthesis has been followed by EPR. The results show that the immobilization of the Cu2+ ion/complex and the formation of the PMO materials are taking place simultaneously. The copper ions are found to be situated on the inner surface of the mesopores of the materials and are accessible, which will be beneficial for the catalytic applications.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 4.029
Times cited: 11
DOI: 10.1039/c4dt03719g
|
“Non-ionic surfactant (C13EOm, m=6, 12 and 18) for large pore mesoporous molecular sieves preparation”. Blin JL, Becue A, Pauwels B, Van Tendeloo G, Su BL, Microporous and mesoporous materials 44/45, 41 (2001). http://doi.org/10.1016/S1387-1811(01)00167-6
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.615
Times cited: 27
DOI: 10.1016/S1387-1811(01)00167-6
|
“Synthesis, structure and magnetic ordering of the mullite-type Bi2Fe4-xCrxO9 solid solutions with a frustrated pentagonal Cairo lattice”. Rozova MG, Grigoriev VV, Bobrikov IA, Filimonov DS, Zakharov KV, Volkova OS, Vasiliev AN, Antipov EV, Tsirlin AA, Abakumov AM, Journal of the Chemical Society : Dalton transactions 45, 1192 (2016). http://doi.org/10.1039/c5dt04296h
Abstract: Highly homogeneous mullite-type solid solutions Bi2Fe4-xCrxO9 (x = 0.5, 1, 1.2) were synthesized using a soft chemistry technique followed by a solid-state reaction in Ar. The crystal structure of Bi2Fe3CrO9 was investigated using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy (S.G. Pbam, a = 7.95579(9) angstrom , b = 8.39145(9) angstrom, c = 5.98242(7) angstrom, R-F(X-ray) = 0.022, R-F(neutron) = 0.057). The ab planes in the structure are tessellated with distorted pentagonal loops built up by three tetrahedrally coordinated Fe sites and two octahedrally coordinated Fe/Cr sites, linked together in the ab plane by corner-sharing forming a pentagonal Cairo lattice. Magnetic susceptibility measurements and powder neutron diffraction show that the compounds order antiferromagnetically (AFM) with the Neel temperatures decreasing upon increasing the Cr content from T-N similar to 250 K for x = 0 to T-N similar to 155 K for x = 1.2. The magnetic structure of Bi2Fe3CrO9 at T = 30 K is characterized by a propagation vector k = (1/2,1/2,1/2). The tetrahedrally coordinated Fe cations form singlet pairs within dimers of corner-sharing tetrahedra, but spins on the neighboring dimers are nearly orthogonal. The octahedrally coordinated (Fe, Cr) cations form antiferromagnetic up-up-down-down chains along c, while the spin arrangement in the ab plane is nearly orthogonal between nearest neighbors and collinear between second neighbors. The resulting magnetic structure is remarkably different from the one in pure Bi2Fe4O9 and features several types of spin correlations even on crystallographically equivalent exchange that may be caused by the simultaneous presence of Fe and Cr on the octahedral site.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
DOI: 10.1039/c5dt04296h
|
“Quantum transport in a cylindrical sub-0.1 μm silicon-based MOSFET”. Balaban SN, Pokatilov EP, Fomin VM, Gladilin VN, Devreese JT, Magnus W, Schoenmaker W, van Rossum M, Sorée B, Solid-State Electronics 46, 435 (2002). http://doi.org/10.1016/S0038-1101(01)00117-4
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 1.58
Times cited: 16
DOI: 10.1016/S0038-1101(01)00117-4
|
“Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution”. Mikhailova D, Kuratieva NN, Utsumi Y, Tsirlin AA, Abakumov AM, Schmidt M, Oswald S, Fuess H, Ehrenberg H, Journal of the Chemical Society : Dalton transactions 46, 1606 (2017). http://doi.org/10.1039/C6DT04389E
Abstract: The substitution of vanadium in vanadium dioxide VO2 influences the critical temperatures of structural and metal-to-insulator transitions in different ways depending on the valence of the dopant. Rhenium adopts valence states between + 4 and + 7 in an octahedral oxygen surrounding and is particularly interesting in this context. Structural investigation of V1-xRexO2 solid solutions (0.01 <= x <= 0.30) between 80 and 1200 K using synchrotron X-ray powder diffraction revealed only two polymorphs that resemble VO2: the low-temperature monoclinic MoO2-type form (space group P2(1)/c), and the tetragonal rutile-like form (space group P4(2)/mnm). However, for compositions with 0.03 < x <= 0.15 a phase separation in the solid solution was observed below 1000 K upon cooling down from 1200 K, giving rise to two isostructural phases with slightly different lattice parameters. This is reflected in the appearance of two metal-toinsulator transition temperatures detected by magnetization and specific heat measurements. Comprehensive X-ray photoelectron spectroscopy studies showed that an increased amount of Re leads to a change in the Re valence state from solely Re6+ at a low doping level (<= 3 at% Re) via mixed-valence states Re4+/Re6+ for at least 0.03 < x <= 0.10, up to nearly pure Re4+ in V0.70Re0.30O2. Thus, compositions V1-xRexO2 with only one valence state of Re in the material (Re6+ or Re4+) can be obtained as a single phase, while intermediate compositions are subjected to a phase separation, presumably due to different valence states of Re.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
Times cited: 1
DOI: 10.1039/C6DT04389E
|
“Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5”. Hasanli N, Gauquelin N, Verbeeck J, Hadermann J, Hayward MA, Journal of the Chemical Society : Dalton transactions 47, 15783 (2018). http://doi.org/10.1039/C8DT03463J
Abstract: Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
DOI: 10.1039/C8DT03463J
|
“Crystal structure and magnetic properties of the Cr-doped spiral antiferromagnet BiMnFe2O6”. Batuk D, de Dobbelaere C, Tsirlin AA, Abakumov AM, Hardy A, van Bael MK, Greenblatt M, Hadermann J, Materials research bulletin 48, 2993 (2013). http://doi.org/10.1016/j.materresbull.2013.04.038
Abstract: We report the Cr3+ for Mn3+ substitution in the BiMnFe2O6 structure. The BiCrxMn1-xFe2O6 solid solution is obtained by the solution-gel synthesis technique for the x values up to 0.3. The crystal structure investigation using a combination of X-ray powder diffraction and transmission electron microscopy demonstrates that the compounds retain the parent BiMnFe2O6 structure (for x = 0.3, a = 5.02010(6)angstrom, b = 7.06594(7)angstrom, c = 12.6174(1)angstrom, S.G. Pbcm, R-1 = 0.036, R-p = 0.011) with only a slight decrease in the cell parameters associated with the Cr3+ for Mn3+ substitution. Magnetic susceptibility measurements suggest strong similarities in the magnetic behavior of BiCrxMn1-xFe2O6 (x = 0.2; 0.3) and parent BiMnFe2O6. Only T-N slightly decreases upon Cr doping that indicates a very subtle influence of Cr3+ cations on the magnetic properties at the available substitution rates. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.446
Times cited: 3
DOI: 10.1016/j.materresbull.2013.04.038
|
“Structure and magnetic properties of a new anion-deficient perovskite Pb2Ba2BiFe4ScO13 with crystallographic shear structure”. Batuk M, Tyablikov OA, Tsirlin AA, Kazakov SM, Rozova MG, Pokholok KV, Filimonov DS, Antipov EV, Abakumov AM, Hadermann J, Materials research bulletin 48, 3459 (2013). http://doi.org/10.1016/j.materresbull.2013.05.028
Abstract: Pb2Ba2BiFe4ScO13, a new n = 5 member of the oxygen-deficient perovskite-based A(n)B(n)O(3n-2) homologous series, was synthesized using a solid-state method. The crystal structure of Pb2Ba2BiFe4ScO13 was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mossbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) angstrom, b = 4.0426(1) angstrom, and c=27.3435(1) angstrom. In the Pb2Ba2BiFe4ScO13 structure, quasi-two-dimensional perovskite blocks are periodically interleaved with 1/2[1 1 0] ((1) over bar 0 1)(p) crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO6 octahedra are transformed into chains of edge-sharing FeO5 distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe3+ and Sc3+. The chains of the FeO5 pyramids and (Fe,Sc)O-6 octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb2+). The remaining A-cations (Bi3+, Ba2+) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb2Ba2BiFe4ScO13 is antiferromagnetically ordered below T-N approximate to 350 K. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.446
Times cited: 2
DOI: 10.1016/j.materresbull.2013.05.028
|
“Interpreting technical evidence from spectral imaging of paintings by Edouard Manet in the Courtauld Gallery”. Amato SR, Burnstock A, Cross M, Janssens K, Rosi F, Cartechini L, Fontana R, Dal Fovo A, Paolantoni M, Grazia C, Romani A, Michelin A, Andraud C, Tournie A, Dik J, X-ray spectrometry
T2 –, MA-XRF Workshop on Developments and Applications of Macro-XRF in, Conservation, Art, and Archeology, SEP 24-25, 2017, Trieste, ITALY 48, 282 (2019). http://doi.org/10.1002/XRS.2828
Abstract: The paintings by edouard Manet in The Courtauld Gallery Dejeuner sur l'herbe (1863-68), Marguerite de Conflans en Toilette de Bal (1870-1880), Banks of the Seine at Argenteuil (1874), and A Bar at the Folies-Bergere (1882) were investigated for the first time using a range of non-invasive in situ analyses. The aims of the study were to investigate the painting techniques and materials used for this group of works and to critically evaluate the technical evidence derived from the integrated use of imaging techniques and portable spectroscopic methods in this context. The paintings were investigated by means of macro X-ray fluorescence (MA-XRF), reflection spectral imaging, portable UV-Vis-NIR spectroscopy, portable Raman spectroscopy, and reflection FTIR. MA-XRF and reflection spectral imaging allowed visualising elements in the compositions that were not visible using traditional methods of technical study. For example, MA-XRF analysis of Dejeuner sur l'herbe revealed elements of the development of the composition that provided new evidence to consider its relationship to other versions of the composition. The study also highlighted questions about the interpretation of elemental distribution maps and spectral images that did not correspond to the reworking visible in X-radiographs. For example, in A Bar at the Folies-Bergere Manet made numerous changes during painting, which were not clearly visualised with any of the techniques used. The research has wider implications for the study of Impressionist paintings, as the results will support technical studies of works by other artists of the period who used similar materials and painting methods.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.298
DOI: 10.1002/XRS.2828
|
“Slicing the Perovskite structure with crystallographic shear planes : the AnBnO3n-2 homologous series”. Abakumov AM, Hadermann J, Batuk M, d' Hondt H, Tyablikov OA, Rozova MG, Pokholok KV, Filimonov DS, Sheptyakov DV, Tsirlin AA, Niermann D, Hemberger J, Van Tendeloo G, Antipov EV, Inorganic chemistry 49, 9508 (2010). http://doi.org/10.1021/ic101233s
Abstract: A new AnBnO3n−2 homologous series of anion-deficient perovskites has been evidenced by preparation of the members with n = 5 (Pb2.9Ba2.1Fe4TiO13) and n = 6 (Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16) in a single phase form. The crystal structures of these compounds were determined using a combination of transmission electron microscopy and X-ray and neutron powder diffraction (S.G. Ammm, a = 5.74313(7), b = 3.98402(4), c = 26.8378(4) Å, RI = 0.035, RP = 0.042 for Pb2.9Ba2.1Fe4TiO13 and S.G. Imma, a = 5.7199(1), b = 3.97066(7), c = 32.5245(8) Å, RI = 0.032, RP = 0.037 for Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16). The crystal structures of the AnBnO3n−2 homologues are formed by slicing the perovskite structure with (01)p crystallographic shear (CS) planes. The shear planes remove a layer of oxygen atoms and displace the perovskite blocks with respect to each other by the 1/2[110]p vector. The CS planes introduce edge-sharing connections of the transition metal−oxygen polyhedra at the interface between the perovskite blocks. This results in intrinsically frustrated magnetic couplings between the perovskite blocks due to a competition of the exchange interactions between the edge- and the corner-sharing metal−oxygen polyhedra. Despite the magnetic frustration, neutron powder diffraction and Mssbauer spectroscopy reveal that Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 are antiferromagnetically ordered below TN = 407 and 343 K, respectively. The Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 compounds are in a paraelectric state in the 5−300 K temperature range.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 23
DOI: 10.1021/ic101233s
|
“The high-temperature polymorphs of K3AlF6”. King G, Abakumov AM, Woodward PM, Llobet A, Tsirlin AA, Batuk D, Antipov EV, Inorganic chemistry 50, 7792 (2011). http://doi.org/10.1021/ic200956a
Abstract: The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 19
DOI: 10.1021/ic200956a
|
“Expanding the Ruddlesden-Popper manganite family : the n=3 La3.2Ba0.8Mn3O10 Member”. Hadermann J, Abakumov AM, Tsirlin AA, Rozova MG, Sarakinou E, Antipov EV, Inorganic chemistry 51, 11487 (2012). http://doi.org/10.1021/ic301332e
Abstract: La3.2Ba0.8Mn3O10, a representative of the rare n = 3 members of the Ruddlesden-Popper manganites A(n+1)Mn(n)O(3n+1), was synthesized in an evacuated sealed silica tube. Its crystal structure was refined from a combination of powder X-ray diffraction (PXD) and precession electron diffraction (PED) data, with the rotations of the MnO6 octahedra described within the symmetry-adapted mode approach (space group Cccm, a = 29.068(1) angstrom, b = 5.5504(5) angstrom, c = 5.5412(5) angstrom; PXD RF = 0.053, RP = 0.026; PED RF = 0.248). The perovskite block in La3.2Ba0.8Mn3O10 features an octahedral tilting distortion with out-of-phase rotations of the Mn06 octahedra according to the (Phi,Phi,0)(Phi,Phi,0) mode, observed for the first time in the n = 3 Ruddlesden-Popper structures. The Mn06 octahedra demonstrate a noticeable deformation with the elongation of two apical Mn-O bonds due to the Jahn-Teller effect in the Mn3+ cations. The relationships between the octahedral tilting distortion, the ionic radii of the cations at the A- and B-positions, and the mismatch between the perovslcite and rock-salt blocks of the Ruddlesden-Popper structure are discussed. At low temperatures, La3.2Ba0.8Mn3O10 reveals a sizable remnant magnetization of about 1.3 mu(B)/Mn at 2K, and shows signatures of spin freezing below 150 K.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 2
DOI: 10.1021/ic301332e
|
“Effect of lone-electron-pair cations on the orientation of crystallographic shear planes in anion-deficient perovskites”. Batuk D, Batuk M, Abakumov AM, Tsirlin AA, McCammon CM, Dubrovinsky L, Hadermann J, Inorganic chemistry 52, 10009 (2013). http://doi.org/10.1021/ic4012845
Abstract: Factors affecting the structure and orientation of the crystallographic shear (CS) planes in anion-deficient perovskites are investigated using the (Pb1−zSrz)1−xFe1+xO3−y perovskites as a model system. The orientation of the CS planes in the system varies unevenly with z. A comparison of the structures with different CS planes revels that the orientation of the CS planes is governed mainly by the stereochemical activity of the lone-electron-pair cations inside the perovskite blocks.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 11
DOI: 10.1021/ic4012845
|
“Homologous series of layered perovskites An+1BnO3n-1Cl : crystal and magnetic structure of a new oxychloride Pb4BiFe4O11Cl”. Batuk M, Batuk D, Tsirlin AA, Rozova MG, Antipov EV, Hadermann J, Van Tendeloo G, Inorganic chemistry 52, 2208 (2013). http://doi.org/10.1021/ic302667a
Abstract: The nuclear and magnetic structure of a novel oxychloride Pb4BiFe4O11Cl has been studied over the temperature range 1.5700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb4BiFe4O11Cl is built of truncated (Pb,Bi)3Fe4O11 quadruple perovskite blocks separated by CsCl-type (Pb,Bi)2Cl slabs. The perovskite blocks consist of two layers of FeO6 octahedra located between two layers of FeO5 tetragonal pyramids. The FeO6 octahedra rotate about the c axis, resulting in a √2ap × √2ap × c superstructure. Below TN = 595(17) K, Pb4BiFe4O11Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μB on the octahedral and square-pyramidal iron sites, respectively. Pb4BiFe4O11Cl can be considered a member of the perovskite-based An+1BnO3n1Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 6
DOI: 10.1021/ic302667a
|
“Perovskite-like Mn2O3 : a path to new manganites”. Ovsyannikov SV, Abakumov AM, Tsirlin AA, Schnelle W, Egoavil R, Verbeeck J, Van Tendeloo G, Glazyrin KV, Hanfland M, Dubrovinsky L, Angewandte Chemie 52, 1494 (2013). http://doi.org/10.1002/anie.201208553
Abstract: Korund-artiges ε-Mn2O3 und Perowskit-artiges ζ-Mn2O3, zwei neue Phasen von Mn2O3, wurden unter hohen Drücken bei hohen Temperaturen synthetisiert. Die Manganatome können vollständig die A- und B-Positionen der Perowskitstruktur besetzen. ζ-Mn2O3 (siehe Bild, A-Positionsordnung) enthält Mn in den drei Oxidationsstufen +II, +III und +IV.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 84
DOI: 10.1002/anie.201208553
|