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“Incorporation and localization of substitutional Mn2+ ions in cubic ZnS quantum dots”. Nistor SV, Stefan M, Nistor LC, Goovaerts E, Van Tendeloo G, Physical review : B : condensed matter and materials physics 81, 035336 (2010). http://doi.org/10.1103/PhysRevB.81.035336
Abstract: Multifrequency electron paramagnetic resonance (EPR) and high resolution transmission electron microscopy (HRTEM) investigations were performed on small (2 nm) cubic ZnS nanocrystals (quantum dotsQDs) doped with 0.2% mol Mn2+, self-assembled into a mesoporous structure. The EPR data analysis shows that the substitutional Mn2+ ions are localized at Zn2+ sites subjected to a local axial lattice distortion, resulting in the observed zero-field-splitting parameter |D|=41×10−4 cm−1. The local distortion is attributed to the presence in the second shell of ligands of a stacking fault or twin, which alters the normal stacking sequence of the cubic structure. The HRTEM results confirm the presence of such extended planar defects in a large percentage of the investigated QDs, which makes possible the proposed substitutional Mn2+ impurity ions localization model. Based on these results it is suggested that the high doping levels of Mn2+ ions observed in cubic ZnS and possible in other II-VI semiconductor QDs prepared at low temperatures can be explained by the assistance of the extended lattice defects in the impurities incorporation.
Keywords: A1 Journal article; Nanostructured and organic optical and electronic materials (NANOrOPT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 55
DOI: 10.1103/PhysRevB.81.035336
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“Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions”. Nistor LC, Nistor SV, Dinca G, Georgeoni P, van Landuyt J, Manfredotti C, Vittone E, Journal of physics : condensed matter 14, 10983 (2002). http://doi.org/10.1088/0953-8984/14/44/414
Abstract: High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp(3) bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 +/- 15 mJ m(-2) is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 7
DOI: 10.1088/0953-8984/14/44/414
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“Crystallographic aspects related to advanced tribological multilayers of Cr/CrN and Ti/TiN types produced by pulsed laser deposition (PLD)”. Major L, Morgiel J, Major B, Lackner JM, Waldhauser W, Ebner R, Nistor L, Van Tendeloo G, Surface and coatings technology 200, 6190 (2006). http://doi.org/10.1016/j.surfcoat.2005.11.021
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 32
DOI: 10.1016/j.surfcoat.2005.11.021
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“Characterization of {111} planar defects induced in silicon by hydrogen plasma treatments”. Ghica C, Nistor LC, Bender H, Richard O, Van Tendeloo G, Ulyashin A;, Philosophical magazine 86, 5137 (2006). http://doi.org/10.1080/14786430600801443
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.505
Times cited: 12
DOI: 10.1080/14786430600801443
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“Electrochemical growth and characterization of nanostructured ZnO thin films”. Ghica C, Enculescu I, Nistor LC, Matei E, Van Tendeloo G, Journal of optoelectronics and advanced materials 10, 3237 (2008)
Abstract: ZnO is a wide band-gap (ca. 3.4 eV) semiconductor, piezoelectric, pyroelectric, biocompatible, transparent in the visible spectrum and UV light emitting material. The fabrication in 2001 of the first nanobelts of semiconductor oxide materials lead to a rapid expansion of researches concerning one dimensional nanostructures (nanotubes, nanowires, nanobelts), given their possible application in optics, optoelectronics, piezoelectricity, catalysis. Researches carried on up to date evidenced the possibility to obtain an extraordinary variety of ZnO nanostructures, in function of the experimental parameters and the used growth methods. In this work we present morphostructural results on nanostructured ZnO layers obtained by electrochemical deposition. The films have been grown on gold covered glass plates and Si wafers, in various experimental conditions such as: nature of the wetting agents, electrical polarization of the substrate (continuous, pulsed). The influence of the growth conditions on the crystalline structure and morphology of the films is revealed by scanning and transmission electron microscopy studies. The films show a variety of growth morphologies, from entangled-wires-like to honeycomb-like layers. These large-specific-surface layers will be tested as nanostructured substrates for photovoltaic cells with improved efficiency.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.449
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“HRTEM studies of dislocations in cubic BN”. Nistor LC, Van Tendeloo G, Dincã, G, Physica status solidi: A: applied research 201, 2578 (2004). http://doi.org/10.1002/pssa.200405192
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 8
DOI: 10.1002/pssa.200405192
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“Structural studies of diamond thin films grown from the arc plasma”. Nistor LC, van Landuyt J, Journal of materials research 12, 2533 (1998)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.673
Times cited: 13
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“Revealing nanoscale structural TEM/HRTEM: application on ferroelectric ordering by PMN-PT relaxor ferroelectric”. Ghica C, Nistor L, Van Tendeloo G, Journal of optoelectronics and advanced materials 10, 2328 (2008)
Abstract: Nano-scale ordering may be revealed in transmission electron microscopy (TEM) by at least three techniques that will be presented in this work: selected area electron diffraction, conventional TEM and high-resolution TEM. Digital image processing is used to extract additional information from the high-resolution micrographs. The described methods are illustrated in a microstructural and compositional study of a 90%Pb(Mg1/3Nb2/3)O-3-10%PbTiO2 ceramic sample. High-resolution images reveal the presence of ordered compositional nano-domains, observable in two specific crystallographic orientations. Antiphase boundaries lying in the (111) planes separate them, while (100) and (111) facets separate the ordered domains from the disordered matrix.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.449
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“Strain mapping around dislocations in diamond and cBN”. Willems B, Nistor L, Ghica C, Van Tendeloo G, Physica status solidi: A: applied research 202, 2224 (2005). http://doi.org/10.1002/pssa.200561923
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 4
DOI: 10.1002/pssa.200561923
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“The study of a crater forming on the surface of a Ti target submitted to multipulse excimer laser irradiation under low pressure N2”. Teodorescu VS, Mihailescu IN, Gyorgy E, Luches A, Martino M, Nistor LC, van Landuyt J, Hermann J, Journal of modern optics 43, 1773 (1996). http://doi.org/10.1080/095003496154815
Abstract: A Ti target was submitted to laser ablation in low ambient pressure N-2. Electron microscopy examination of the cross-section of the crater zone forming on the Ti target, and XPS analyses, indicate that there is a small effect on the nitridation processes taking place on and in the vicinity of the target. The studies show a zone influenced by the multipulse laser treatment extending beneath the crater down to a depth of the same order of magnitude as the crater depth (i.e. similar to 10 mu m). In this zone, TiN could be identified as being present only in traces, while the whole zone exhibited a layer structure with differences in morphology and mechanical wear.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.008
Times cited: 11
DOI: 10.1080/095003496154815
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“Thermal stability of atomic layer deposited Zr:Al mixed oxide thin films: an in situ transmission electron microscopy study”. Nistor LC, Richard O, Zhao C, Bender H, Van Tendeloo G, Journal of materials research 20, 1741 (2005). http://doi.org/10.1557/JMR.2005.0217
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.673
DOI: 10.1557/JMR.2005.0217
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“The influence of the h-BN morphology and structure on the c-BN growth”. Nistor L, Teodorescu V, Ghica C, van Landuyt J, Dinca G, Georgeoni P, Diamond and related materials
T2 –, 11th European Conference on Diamond, Diamond-like Materials, Carbon, Nanotubes, Nitrides and Silicon Carbide (Diamond 2000), SEP 03-08, 2000, OPORTO, PORTUGAL 10, 1352 (2001). http://doi.org/10.1016/S0925-9635(00)00377-0
Abstract: The morphology and structure of hexagonal graphitic BN (h-BN) powders with graphitization indices GI <5, used as precursors for the synthesis of cubic BN (c-BN) crystals, has been investigated by transmission electron microscopy in diffraction contrast and high resolution. We show that besides the GI, which is a general parameter for controlling the structural quality of h-EN ponders, some other microstructural features strongly influence the synthesis of c-BN. In our opinion, the high reactivity of some h-BN powders results from the presence of some nucleation centers for c-BN, observed at the edges of the h-BN particles. They are formed by a rearrangement of the graphitic (0002) planes by bending back, joining in pairs and forming locally nanoarches (half nanotubes). In these particular places, the nature of bonding locally turns towards sp(3), as in the case of c-BN, (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 17
DOI: 10.1016/S0925-9635(00)00377-0
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“Crystallographic aspects related to the high pressure-high temperature phase transformation of boron nitride”. Nistor LC, Van Tendeloo G, Dincã, G, Philosophical magazine 85, 1145 (2005). http://doi.org/10.1080/14786430412331325058
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.505
Times cited: 13
DOI: 10.1080/14786430412331325058
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“Ordering and defects in BanTaxTiyO3n ternary oxides”. Nistor L, Van Tendeloo G, Amelinckx S, Shpanchenko RV, van Landuyt J, Electron Microscopy 1994, Vols 2a And 2b: Applications In Materials Sciences , 869 (1994)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“High resolution electron microscopy and electron spin resonance studies on cubic boron nitride crystals made by high-pressure/high-temperature synthesis”. Nistor L, Nistor SV, Dincã, G, van Landuyt J, Schoemaker D, Copaciu V, Georgeoni P, Arnici N, Diamonds an related materials 8, 738 (1999). http://doi.org/10.1016/S0925-9635(98)00282-9
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 7
DOI: 10.1016/S0925-9635(98)00282-9
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“Mesoseopic ordering in the 0.9 Pb(Mg1/3Nb2/3)O3-0.1 PbTiO3 relaxor ferroelectric : a HRTEM study”. Nistor LC, Ghica C, Van Tendeloo G, Physica status solidi: C: conferences and critical reviews 4, 736 (2007). http://doi.org/10.1002/pssc.200673753
Abstract: We report a microstructural and compositional study of a 90% Pb(Mg1/3Nb2/3)O-3 – 10% PbTiO3 ceramic sample. High resolution transmission electron microscopy (HRTEM) revealed the presence of compositional ordered nano-domains (1 – 4 mn), observable in two specific orientations, [0 (1) over bar 1] and [1 1 (2) over bar]. However, the visibility and the ordering degree of the nano-domains on the HRTEM images are not at all obvious. Fourier filtering of the images clearly revealed the ordered domains. Antiphase boundaries lying in the (111) planes separate them, while (100) and (111) facets separate the ordered domains from the disordered matrix. Their shape is plate-like, not uniformly spread in the disordered matrix. Their average size varies in different regions of the sample, most probably due to a non-uniform distribution of Ti, as observed by energy dispersive X-ray spectroscopy. (c) 2007 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 2
DOI: 10.1002/pssc.200673753
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“In situ transmission electron microscopy study of the silicidation process in Co thin films on patterned (001) Si substrates”. Ghica C, Nistor L, Bender H, Steegen A, Lauwers A, Maex K, van Landuyt J, Journal of materials research 16, 701 (2001). http://doi.org/10.1557/JMR.2001.0121
Abstract: The results of an in situ transmission electron microscopy study of the formation of Co-silicides on patterned (001) Si substrates are discussed. It is shown that the results of the in situ heating experiments agreed very well with the data based on standard rapid thermal annealing experiments. Fast heating rates resulted in better definition of the silicide lines. Also, better lines were obtained for samples that received already a low-temperature ex situ anneal. A Ti cap layer gave rise to a higher degree of epitaxy in the CoSi2 silicide.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.673
Times cited: 4
DOI: 10.1557/JMR.2001.0121
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“HREM of defects in cubic boron nitride single crystals”. Nistor LC, van Landuyt J, Dincã, G, , 695 (1998)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“High resolution TEM observation of in situ colloid formation in CaF2 crystals”. Teodorescu VS, Nistor LC, van Landuyt J, Materials science forum 239-241, 671 (1997)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 3
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“A synchrotron radiation, HRTEM, X-ray powder diffraction, and Raman spectroscopic study of malayaite, CaSnSiO5”. Groat LA, Kek S, Bismayer U, Schmidt C, Krane HG, Meyer H, Nistor L, Van Tendeloo G, The American mineralogist 81, 595 (1996)
Abstract: Synchrotron radiation, high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction, and Raman spectroscopy were used to study the structure and thermal behavior of malayaite, CaSnSiO5. No indications of deviation from A2/a symmetry and no structural transitions were observed between 100 and 870 K. HRTEM revealed that the material is free of domains and antiphase boundaries. However, the lattice constants, cell volume, and Raman-active phonons show a thermal discontinuity near 500 K, which is possibly related to variation of the coordination sphere around the highly anisotropic Ca position.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.964
Times cited: 19
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“Structural studies on new ternary oxides Ba8Ta4Ti3O24 and Ba10Ta7.04Ti1.2O30”. Shpanchenko RV, Nistor L, Van Tendeloo G, van Landuyt J, Amelinckx S, Journal of solid state chemistry 114, 560 (1995). http://doi.org/10.1006/jssc.1995.1086
Abstract: The ternary oxides Ba8Ta4Ti3O24 and Ba10Ta7.04Ti1.2O30 were synthesized and their crystal structures and defects were studied by means of X-ray powder diffraction, electron diffraction, and high resolution electron microscopy. The crystal structure of Ba8Ta4Ti3O24 is based on the 8H (cchc)(2) close-packed stacking (a 10.0314 Angstrom, c = 18.869 Angstrom, SG P6(3)/mcm, Z = 3) and that of Ba10Ta7.04Ti1.2O30 and on the 10H (cchcc)(2) close-packed stacking (a = 5.7981 Angstrom, c = 23.755 Angstrom, SG P6(3)/mmc, Z = 1) of BaO3 layers. The structural refinements gave the following values for the R factors for Ba8Ta4Ti3O24 (Ba10Ta7.04Ti1.2O30) R(I) = 0.041 (0.039), R(P) = 0.108 (0.118), and R(wP) = 0.094 (0.099). The main feature of both structures is the presence of two types of face-sharing octahedra (FSO) with different occupancies by Ta atoms, Ti atoms, and vacancies, which results in the formation of a superstructure. It was shown that in the Ba8Ta4Ti3O24 structure these pairs of FSO occur in an ordered fashion and in the Ba10Ta7.04Ti1.2O30 structure in a disordered fashion. The existence of the wide range of solid solutions was shown to be also a consequence of the presence of one of the two types of face-sharing octahedra. (C) 1995 Academic Press, Inc,
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 23
DOI: 10.1006/jssc.1995.1086
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“Direct evidence of spontaneous quantum dot formation in a thick InGaN epilayer”. Nistor L, Bender H, Vantomme A, Wu MF, van Landuyt J, O'Donnell KP, Martin R, Jacobs K, Moerman I, Applied physics letters 77, 507 (2000). http://doi.org/10.1063/1.127026
Abstract: We report a direct observation of quantum dots formed spontaneously in a thick InGaN epilayer by high resolution transmission electron microscopy. Investigation of a (280 nm thick) In0.22Ga0.78N single layer, emitting in the blue/green spectral region, reveals quantum dots with estimated sizes in the range of 1.5-3 nm. Such sizes are in very good agreement with calculations based on the luminescence spectra of this specimen. (C) 2000 American Institute of Physics. [S0003-6951(00)00930-X].
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 44
DOI: 10.1063/1.127026
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“A microstructural study of the thermal stability of atomic layer deposited Al2O3 thin films”. Nistor LC, Richard O, Zhao O, Bender H, Stesmans A, Van Tendeloo G, Institute of physics conference series
T2 –, Microscopy of semiconducting materials , 397 (2003)
Abstract: The thermal stability of amorphous Al2O3 films (similar to8 and 80 nut thick) deposited by atomic layer deposition on HF-last and thin SiO2 covered (001) Si substrates is studied by transmission electron microscopy. The layers are in- and ex-situ annealed in the same temperature range.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“TEM characterization of extended defects induced in Si wafers by H-plasma treatment”. Ghica C, Nistor LC, Bender H, Richard O, Van Tendeloo G, Ulyashin A, Journal of physics: D: applied physics 40, 395 (2007). http://doi.org/10.1088/0022-3727/40/2/016
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.588
Times cited: 10
DOI: 10.1088/0022-3727/40/2/016
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“In situ study of the phase transition in Bi2Ti4O11”. Nistor L, Van Tendeloo G, Amelinckx S, Kahlenberg V, Böhm H, Journal of solid state chemistry 119, 281 (1995). http://doi.org/10.1016/0022-4596(95)80042-N
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 10
DOI: 10.1016/0022-4596(95)80042-N
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“Microstructural characterization of diamond films deposited on c-BN crystals”. Nistor L, Buschmann V, Ralchenko V, Dinca G, Vlasov I, van Landuyt J, Fuess H, Diamond and related materials
T2 –, 10th European Conference on Diamond, Diamond-Like Materials, Nitrides, and Silicon Carbide (Diamond 1999), SEP 12-17, 1999, PRAGUE, CZECH REPUBLIC 9, 269 (2000). http://doi.org/10.1016/S0925-9635(99)00246-0
Abstract: The morphology and structure of diamond films, deposited on cubic boron nitride (c-BN) crystals by microwave-plasma-enhanced chemical vapor deposition, is studied by high-resolution scanning electron microscopy and micro-Raman spectroscopy. The c-BN crystals, with sizes of 200 to 350 mu m and grown by a high-temperature/high-pressure technique, were embedded in a copper holder, and used as substrates in deposition runs of 15 min to 5 h. The nucleation centers for diamond appear as well-shaped cuboctahedral crystallites, having diameters of approximately 100 nm. With increasing deposition time the diamond crystallites grew larger, forming islands on the c-BN faces. In some cases, epitaxial growth was observed on the (111) c-BN faces where coalesced particles gave rise to very smooth regions. A number of diamond crystals with peculiar shapes are observed, such as a pseudo five-fold symmetry due to multiple twinning. Moreover, both randomly distributed carbon tubes, about 100 nn in diameter and 1 mu m in length, and spherically shaped features are observed in samples prepared under the typical conditions of diamond deposition, this effect being ascribed to the influence of plasma-sputtered copper contamination. Quite unusual diamond crystals with a deep, pyramidal-shaped hole in the middle grew on the copper substrate between the c-BN crystals. (C) 2000 Elsevier Science S.A. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 9
DOI: 10.1016/S0925-9635(99)00246-0
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“Gallium colloid formation during ion implantation of glass”. Hole DE, Townsend PD, Barton JD, Nistor LC, van Landuyt J, Journal of non-crystalline solids 180, 266 (1995). http://doi.org/10.1016/0022-3093(94)00477-3
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.766
Times cited: 34
DOI: 10.1016/0022-3093(94)00477-3
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“Colloid size distributions in ion implanted glass”. Nistor LC, van Landuyt J, Barton JD, Hole DE, Skelland ND, Townsend PD, Journal of non-crystalline solids 162, 217 (1993). http://doi.org/10.1016/0022-3093(93)91240-4
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.766
Times cited: 63
DOI: 10.1016/0022-3093(93)91240-4
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“High resolution electron microscopic study of Ba7Sc6Al2O19 and related phases”. Shpanchenko RV, Nistor L, Van Tendeloo G, Amelinckx S, Antipov EV, Kovba LM, Journal of solid state chemistry 113, 193 (1994). http://doi.org/10.1006/jssc.1994.1359
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 3
DOI: 10.1006/jssc.1994.1359
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“Structural study of the new complex oxides Ba5-ySryR2-xAl2Zr1+xO13+x/2 (R=Gd-Lu, Y, Sc)”. Shpanchenko RV, Abakumov AM, Antipov EV, Nistor L, Van Tendeloo G, Amelinckx S, Journal of solid state chemistry 118, 180 (1995). http://doi.org/10.1006/jssc.1995.1329
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 8
DOI: 10.1006/jssc.1995.1329
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