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“Compositionally induced phase transition in the Ca2MnGa1-xAlxO5 solid solutions: ordering of tetrahedral chains in brownmillerite structure”. Abakumov AM, Kalyuzhnaya AS, Rozova MG, Antipov EV, Hadermann J, Van Tendeloo G, Solid state sciences 7, 801 (2005). http://doi.org/10.1016/j.solidstatesciences.2005.01.020
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.811
Times cited: 38
DOI: 10.1016/j.solidstatesciences.2005.01.020
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“Local structure of perovskite-based “Pb2Fe2O5””. Hadermann J, Abakumov AM, Nikolaev IV, Antipov EV, Van Tendeloo G, Solid state sciences 10, 382 (2008). http://doi.org/10.1016/j.solidstatesciences.2007.12.008
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.811
Times cited: 29
DOI: 10.1016/j.solidstatesciences.2007.12.008
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“Synthesis and investigation of novel Mn-based oxyfluoride Sr2Mn2O5-xF1+x”. Lobanov MV, Abakumov AM, Sidorova AV, Rozova MG, D'yachenko OG, Antipov EV, Hadermann J, Van Tendeloo G, Solid state sciences 4, 19 (2002). http://doi.org/10.1016/S1293-2558(01)01209-2
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.811
Times cited: 21
DOI: 10.1016/S1293-2558(01)01209-2
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“Determination of spinel content in cycled Li1.2Ni0.13Mn0.54Co0.13O2 using three-dimensional electron diffraction and precession electron diffraction”. Quintelier M, Perkisas T, Poppe R, Batuk M, Hendrickx M, Hadermann J, Symmetry-Basel 13, 1989 (2021). http://doi.org/10.3390/SYM13111989
Abstract: Among lithium battery cathode materials, Li1.2Ni0.13Mn0.54Co0.13O2 (LR-NMC) has a high theoretical capacity, but suffers from voltage and capacity fade during cycling. This is partially ascribed to transition metal cation migration, which involves the local transformation of the honeycomb layered structure to spinel-like nano-domains. Determination of the honeycomb layered/spinel phase ratio from powder X-ray diffraction data is hindered by the nanoscale of the functional material and the domains, diverse types of twinning, stacking faults, and the possible presence of the rock salt phase. Determining the phase ratio from transmission electron microscopy imaging can only be done for thin regions near the surfaces of the crystals, and the intense beam that is needed for imaging induces the same transformation to spinel as cycling does. In this article, it is demonstrated that the low electron dose sufficient for electron diffraction allows the collection of data without inducing a phase transformation. Using calculated electron diffraction patterns, we demonstrate that it is possible to determine the volume ratio of the different phases in the particles using a pair-wise comparison of the intensities of the reflections. Using this method, the volume ratio of spinel structure to honeycomb layered structure is determined for a submicron sized crystal from experimental three-dimensional electron diffraction (3D ED) and precession electron diffraction (PED) data. Both twinning and the possible presence of the rock salt phase are taken into account. After 150 charge-discharge cycles, 4% of the volume in LR-NMC particles was transformed irreversibly from the honeycomb layered structure to the spinel structure. The proposed method would be applicable to other multi-phase materials as well.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Impact Factor: 1.457
DOI: 10.3390/SYM13111989
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“Effect of selenium content of CuInSex alloy nanopowder precursors on recrystallization of printed CuInSe2 absorber layers during selenization heat treatment”. E Zaghi A, Buffière M, Koo J, Brammertz G, Batuk M, Verbist C, Hadermann J, Kim WK, Meuris M, Poortmans J, Vleugels J;, Thin solid films : an international journal on the science and technology of thin and thick films , 1 (2014). http://doi.org/10.1016/j.tsf.2014.10.003
Abstract: Polycrystalline CuInSe2 semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe2 semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSex (x = 2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe2 phase during the selenization process was investigated. The nanostructure and phase variation of CuInSex nanopowders were investigated by different characterization techniques. The recrystallization process of the 12 μm thick CuInSex coatings into the CuInSe2 phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSex precursors with lower selenium content showed a more pronounced phase conversion into CuInSe2 compared to the higher selenium content CuInSex precursors. Moreover, the CuInSex (x = 0.5 and 1) precursor resulted in a denser polycrystalline CuInSe2 semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSex precursor system compared to a CuInSe2 phase precursor, and the formation of intermediate CuSe and CuSe2 fluxing phases during selenization.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.879
Times cited: 7
DOI: 10.1016/j.tsf.2014.10.003
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“Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se2 solar cells”. Batuk M, Buffiere M, Zaghi AE, Lenaers N, Verbist C, Khelifi S, Vleugels J, Meuris M, Hadermann J, Thin solid films : an international journal on the science and technology of thin and thick films 583, 142 (2015). http://doi.org/10.1016/j.tsf.2015.03.063
Abstract: For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In,Ga)Se-2 (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aimof improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior to the selenization. We showed that the use of an Air/H2S burn-out step prior to the selenization step increases the CIGSe grain size and reduces the carbon content. However, it leads to the reduction of the solar cell efficiency from 4.5% in the reference sample down to 0.5% in the annealed sample. Detailed transmission electron microscopy analysis, including high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray mapping, was applied to characterize the microstructure of the film and to determine the relationship between microstructure and the solar cell performance. We demonstrated that the relatively low efficiency of the reference solar cells is related not only to the nanosize of the CIGSe grains and presence of the pores in the CIGSe layer, but also to the high amount of secondary phases, namely, In/Ga oxide (or hydroxide) amorphous matter, residuals of organicmatter (carbon), and copper sulfide that is formed at the CIGSe/MoSe2 interface. The annealing in H2S during the burn-out step leads to the formation of the copper sulfide at all grain boundaries and surfaces in the CIGSe layer, which results in the noticeably efficiency drop. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.879
Times cited: 5
DOI: 10.1016/j.tsf.2015.03.063
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“Direct space structure solution from precession electron diffraction data: resolving heavy and light scatterers in Pb13Mn9O25”. Hadermann J, Abakumov AM, Tsirlin AA, Filonenko VP, Gonnissen J, Tan H, Verbeeck J, Gemmi M, Antipov EV, Rosner H, Ultramicroscopy 110, 881 (2010). http://doi.org/10.1016/j.ultramic.2010.03.012
Abstract: The crystal structure of a novel compound Pb13Mn9O25 has been determined through a direct space structure solution with a Monte-Carlo-based global optimization using precession electron diffraction data (a=14.177(3) Å, c=3.9320(7) Å, SG P4/m, RF=0.239) and compositional information obtained from energy dispersive X-ray analysis and electron energy loss spectroscopy. This allowed to obtain a reliable structural model even despite the simultaneous presence of both heavy (Pb) and light (O) scattering elements and to validate the accuracy of the electron diffraction-based structure refinement. This provides an important benchmark for further studies of complex structural problems with electron diffraction techniques. Pb13Mn9O25 has an anion- and cation-deficient perovskite-based structure with the A-positions filled by the Pb atoms and 9/13 of the B positions filled by the Mn atoms in an ordered manner. MnO6 octahedra and MnO5 tetragonal pyramids form a network by sharing common corners. Tunnels are formed in the network due to an ordered arrangement of vacancies at the B-sublattice. These tunnels provide sufficient space for localization of the lone 6s2 electron pairs of the Pb2+ cations, suggested as the driving force for the structural difference between Pb13Mn9O25 and the manganites of alkali-earth elements with similar compositions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 24
DOI: 10.1016/j.ultramic.2010.03.012
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“Crystal structure and magnetic properties of novel reduced V(IV)-based oxide Pb2V5O12”. Shpanchenko RV, Chyornaya VV, Abakumov AM, Antipov EV, Hadermann J, Van Tendeloo G, Kaul E, Geibel C, Sheptyakov D, Balagurov AM, Zeitschrift für anorganische und allgemeine Chemie 627, 2143 (2001). http://doi.org/10.1002/1521-3749(200109)627:9<2143::AID-ZAAC2143>3.0.CO;2-R
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.144
Times cited: 4
DOI: 10.1002/1521-3749(200109)627:9<2143::AID-ZAAC2143>3.0.CO;2-R
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“Mg1-xRhB, a new boridometallide with 2D polyanion”. Alekseeva AM, Abakumov AM, Leithe-Jasper A, Schnelle W, Prots Y, Hadermann J, Van Tendeloo G, Antipov EV, Grin Y, Zeitschrift für anorganische und allgemeine Chemie 631, 1047 (2005). http://doi.org/10.1002/zaac.200400479
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.144
Times cited: 13
DOI: 10.1002/zaac.200400479
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“Layered oxygen vacancy ordering in Nb-doped SrCo1-xFexO3-\delta perovskite”. Van Rompaey S, Dachraoui W, Turner S, Podyacheva OY, Tan H, Verbeeck J, Abakumov A, Hadermann J, Zeitschrift für Kristallographie 228, 28 (2013). http://doi.org/10.1524/zkri.2013.1556
Abstract: The crystal structure of SrCo0.7Fe0.2Nb0.1O2.72 was determined using a combination of precession electron diffraction (PED), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and spatially resolved electron energy loss spectroscopy (STEM-EELS). The structure has a tetragonal P4/mmm symmetry with cell parameters a = b = a(p), c = 2a(p) (a(p) being the cell parameter of the perovskite parent structure). Octahedral BO2 layers alternate with the anion-deficient BO1.4 layers, the different B cations are randomly distributed over both layers. The specific feature of the SrCo0.7Fe0.2NB0.1O2.72 microstructure is a presence of extensive nanoscale twinning resulting in domains with alignment of the tetragonal c-axis along all three cubic direction of the perovskite subcell.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.179
Times cited: 9
DOI: 10.1524/zkri.2013.1556
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