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Author Hadermann, J.; Pérez, O.; Créon, N.; Michel, C.; Hervieu, M.
Title The (3 + 2)D structure of oxygen deficient LaSrCuO3.52 Type A1 Journal article
Year 2007 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 17 Issue 22 Pages 2344-2350
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000247349400020 Publication Date (up) 2007-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 7 Open Access
Notes Supergmr:Hprn-Ct-2000-0021 Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:64749 c:irua:64749 Serial 13
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Author Lepoittevin, C.; Malo, S.; Barrier, N.; Nguyen, N.; Van Tendeloo, G.; Hervieu, M.
Title Long-range ordering in the Bi1-xAexFeO3-x/2 perovskites: Bi1/3Sr2/3FeO2.67 and Bi1/2Ca1/2FeO2.75 Type A1 Journal article
Year 2008 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 181 Issue 10 Pages 2601-2609
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Two-ordered perovskites, Bi1/3Sr2/3FeO2.67 and Bi1/2Ca1/2FeO2.75, have been stabilized and characterized by transmission electron microscopy, Mössbauer spectroscopy and X-ray powder diffraction techniques. They both exhibit orthorhombic superstructures, one with a≈b≈2ap and c≈3ap (S.G.: Pb2n or Pbmn) for the Sr-based compound and one with a≈b≈2ap and c≈8ap (S.G.: B222, Bmm2, B2mm or Bmmm) for the Ca-based one. The high-resolution transmission electron microscopy (HRTEM) images evidence the existence of one deficient [FeOx]∞ layer, suggesting that Bi1/3Sr2/3FeO2.67 and Bi1/2Ca1/2FeO2.75 behave differently compared to their Ln-based homolog. The HAADF-STEM images allow to propose a model of cation ordering on the A sites of the perovskite. The Mössbauer analyses confirm the trivalent state of iron and its complex environment with three types of coordination. Both compounds exhibit a high value of resistivity and the inverse molar susceptibility versus temperature curves evidence a magnetic transition at about 730 K for the Bi1/3Sr2/3FeO2.67 and a smooth reversible transition between 590 and 650 K for Bi1/2Ca1/2FeO2.75.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000260441000008 Publication Date (up) 2008-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 27 Open Access
Notes Esteem 026019 Approved Most recent IF: 2.299; 2008 IF: 1.910
Call Number UA @ lucian @ c:irua:75663 Serial 1839
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Author Gillie, L.J.; Hadermann, J.; Hervieu, M.; Maignan, A.; Martin, C.
Title Oxygen vacancy ordering in the double-layered Ruddlesden-Popper cobaltite Sm2BaCo2O7-\delta Type A1 Journal article
Year 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 20 Issue 19 Pages 6231-6237
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new oxygen-deficient Ruddlesden−Popper (RP) cobaltite Sm2BaCo2O7−δ (δ ≈ 1.0) has been synthesized and the crystal structure elucidated by Rietveld analysis of X-ray powder diffraction (XRD) data and transmission electron microscopy (TEM). The phase crystallizes in a primitive orthorhombic unit cell, with lattice parameters a = 5.4371(4) Å; b = 5.4405(4) Å and c = 19.8629(6) Å, and space group Pnnm. Contrary to other oxygen-deficient cobalt RP phases, the oxygen vacancies are located in the equatorial positions of the [CoO] layers to give an intralayer structure similar to Sr2Mn2O5, which is not usually observed for cobalt-containing materials. The Sm3+ and Ba2+ cations show a strong preference for distinct sites, with the majority of the larger Ba2+ cations situated in the perovskite block layers and Sm3+ cations predominantly in the rock salt layers. Magnetic susceptibility data demonstrate the strong antiferromagnetic (AFM) character of Sm2BaCo2O7−δ.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000259871500038 Publication Date (up) 2008-09-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 7 Open Access
Notes Approved Most recent IF: 9.466; 2008 IF: 5.046
Call Number UA @ lucian @ c:irua:72946 Serial 2548
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Author Lepoittevin, C.; Malo, S.; Nguyen, N.; Hebert, S.; Van Tendeloo, G.; Hervieu, M.
Title A layered iron-rich 2234-type with a mixed valence of iron: the ferrimagnetic Tl-doped Fe2(Sr2-\varepsilonTl\varepsilon)Sr3Fe4O14.65 Type A1 Journal article
Year 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 20 Issue 20 Pages 6468-6476
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new Tl-doped strontium ferrite Fe2(Sr2-Tl)Sr3Fe4O14.65, with an original structure, has been synthesized and structurally characterized by powder X-ray diffraction and transmission electron microscopy. The TGA and Mssbauer studies evidence a mixed valence of iron. The structure exhibits a commensurate modulation, with a F-type subcell a ≈ b ≈ 5.4 Å (≈ ap√2), c ≈ 42 Å with a modulation vector q = αa* with α = 0.4. The supercell parameters have been refined as a= 27.1101(8) Å, b= 5.5187(2) Å and c= 42.0513(9) Å, in the space group Fmmm. The electron diffraction and electron microscopy data of this novel ferrite show that it can be described as a FeTl-2234-type structure corresponding to the intergrowth of a quadruple perovskite slice [(SrFeO2.8)4], with a complex rock salt related slice [Fe2(Sr2-Tl)O3.4]∞, built up of one double iron layer [Fe2O2.4] sandwiched between two [SrO] layers. The HRTEM images show that the oxygen atoms and vacancies are randomly distributed in the perovskite layers while the HAADF STEM images evidence the absence of Tl segregation in the matrix. Fe2(Sr2-Tl)Sr3Fe4O14.65 exhibits a very large value of χ (11emu/mol) at 5 K, which remains large at 400 K; the M(H) loop presents a shape characteristic of ferrimagnetism, with a large coercive field of 0.3 T. The value of magnetization saturates at 400 K at 0.68 μB/Fe. At 10 K, the value of magnetization reaches a maximum of 2 μB/Fe. The resistivity presents a semiconducting-like behavior, with ρ 800 Ω·cm at 300 K.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000260254400030 Publication Date (up) 2008-09-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 8 Open Access
Notes Approved Most recent IF: 9.466; 2008 IF: 5.046
Call Number UA @ lucian @ c:irua:76671 Serial 1804
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Author Lepoittevin, C.; Malo, S.; Van Tendeloo, G.; Hervieu, M.
Title Synthesis and structural mechanisms of the 2201-type ferrites and polytypes: Fe2(Sr2-xAx)FeO6.5-\delta/2 (A = Ba, La, Tl, Pb and Bi) Type A1 Journal article
Year 2009 Publication Solid state sciences Abbreviated Journal Solid State Sci
Volume 11 Issue 3 Pages 595-607
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The Fe2(Sr2 − xAx)FeO6.5 − ä/2 systems have been investigated, by doping the iron rich 2201-type parent structure with Ba2+, La3+ and 5d10 post-transition cations. The syntheses have been carried out up to the limit of the 2201-type solid solutions, in order to test the role of the double iron layer Fe2O2.5 − ä/2. The localisation of the charge carriers in these compounds is consistent with their strong antiferro-magnetism. The investigation was then carried out in the transition part of the diagram up to the formation of stable phases. The study of structural mechanisms was carried using high resolution electron microscopy (transmission and scanning transmission), electron diffraction and energy dispersive spectroscopy. Different non-stoichiometry mechanisms are observed, depending on the electronic structure and chemical properties of the doping elements. The specific behavior of the modulated double iron layer is discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000264644800001 Publication Date (up) 2008-12-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1293-2558; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.811 Times cited 3 Open Access
Notes Esteem 026019 Approved Most recent IF: 1.811; 2009 IF: 1.675
Call Number UA @ lucian @ c:irua:76416 Serial 3437
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Author Lepoittevin, C.; Hadermann, J.; Malo, S.; Pérez, O.; Van Tendeloo, G.; Hervieu, M.
Title Two variants of the 1/2[110]p(203)p crystallographic shear structures: the phasoid Sr0.61Pb0.18(Fe0.75Mn0.25)O2.29 Type A1 Journal article
Year 2009 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 48 Issue 17 Pages 8257-8262
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract For the composition (Sr0.61Pb0.18)(Fe0.75Mn0.25)O2.29, a new modulated crystallographic shear structure, related to perovskite, has been synthesized and structurally characterized by transmission electron microscopy. The structure can be described using a monoclinic supercell with cell parameters am = 27.595(2) Å, bm = 3.8786(2) Å, cm = 13.3453(9) Å, and βm = 100.126(5)°, refined from powder X-ray diffraction data. The incommensurate crystallographic shear phases require an alternative approach using the superspace formalism. This allows a unified description of the incommensurate phases from a monoclinically distorted perovskite unit cell and a modulation wave vector. The structure deduced from the high-resolution transmission electron microscopy and high-angle annular dark-field−scanning transmission electron microscopy images is that of a 1/2[110]p(203)p crystallographic shear structure. The structure follows the concept of a phasoid, with two coexisting variants with the same unit cell. The difference is situated at the translational interface, with the local formation of double (phase 2) or single (phase 1) tunnels, where the Pb cations are likely located.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000269313500032 Publication Date (up) 2009-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 11 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.857; 2009 IF: 4.657
Call Number UA @ lucian @ c:irua:78482 Serial 3786
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Author Malo, S.; Lepoittevin, C.; Pérez, O.; Hébert, S.; Van Tendeloo, G.; Hervieu, M.
Title Incommensurate crystallographic shear structures and magnetic properties of the cation deficient perovskite (Sr0.61Pb0.18)(Fe0.75Mn0.25)O2.29 Type A1 Journal article
Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 22 Issue 5 Pages 1788-1797
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The origin of the incommensurability in the crystallographic shear (CS) structure of the ferri-Manganite (Sr0.61Pb0.18)(Fe0.75Mn0.25)O2.29, related to the cation deficient perovskite, has been determined by careful analysis of the boundaries between the two variants constituting the phasoid. High Resolution Electron Microscopy/HAADF-STEM images allow the structural mechanisms to be understood through the presence of structural units common to both phases, responsible of the incommensurate character observed in the electron diffraction patterns. The structural analysis allows for identifying different types of CS phases in the Pb−Sr−Fe(Mn)−O diagram and shows that the stabilization of the six-sided tunnels requires a higher A/B cationic ratio. A description of these phases is proposed through simple structural building units (SBU), based on chains of octahedra bordered by two pyramids. The (Sr0.61Pb0.18)(Fe0.75Mn0.25)O2.29 CS compound exhibits a strong antiferromagnetic and insulating behavior, similar to the Fe-2201 and terrace ferrites but differs by the presence of a hysteresis, with a small coercive field.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000274929000025 Publication Date (up) 2010-01-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 6 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2010 IF: 6.400
Call Number UA @ lucian @ c:irua:81800 Serial 1593
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Author Bourgeois, J.; Hervieu, M.; Poienar, M.; Abakumov, A.M.; Elkaïm, E.; Sougrati, M.T.; Porcher, F.; Damay, F.; Rouquette, J.; Van Tendeloo, G.; Maignan, A.; Haines, J.; Martin, C.;
Title Evidence of oxygen-dependent modulation in LuFe2O4 Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 85 Issue 6 Pages 064102-064120,10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the previously reported modulations distinctive of the charge-ordering (CO) of the iron species, a new type of incommensurate order is observed, characterized by a vector q⃗1 = α1a⃗M* + γ1c⃗M* (with α1 ≅ 0.55, γ1 ≅ 0.13). In situ heating TEM observations from 300 to 773 K confirm that the satellites associated with q⃗1 vanish completely, only at a temperature significantly higher than the CO temperature. This incommensurate modulation has a displacive character and corresponds primarily to a transverse displacive modulation wave of the Lu cations position, as revealed by the high resolution, high angle annular dark field scanning TEM images and in agreement with synchrotron data refinements. Analyses of vacuum-annealed samples converge toward the hypothesis of a new ordering mechanism, associated with a tiny oxygen deviation from the O4 stoichiometry.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000299896900003 Publication Date (up) 2012-02-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 24 Open Access
Notes Hercules Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:95042 Serial 1095
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Author Hervieu, M.; Damay, F.; Poienar, M.; Elkaim, E.; Rouquette, J.; Abakumov, A.M.; Van Tendeloo, G.; Maignan, A.; Martin, C.
Title Nanostructures in LuFe2O4+\delta Type A1 Journal article
Year 2013 Publication Solid state sciences Abbreviated Journal Solid State Sci
Volume 23 Issue Pages 26-34
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A LuFe2O4+delta sample, previously characterized by X-ray synchrotron and neutron diffraction, has been studied by electron microscopy techniques, in order to get a precise description of its micro- and nanostructures at room temperature. The X-ray synchrotron data vs. temperature show that the monoclinic distortion is associated with the charge ordering; this distortion results in elongated twinning domains, which enhance the complexity of the microstructural state at room temperature. The structural modulation associated with oxygen excess is observed in large domains inside a non modulated matrix, in contrast with the modulations associated with the charge ordering of the Fe2+ and Fe3+ species, which are mostly short-range. The investigation of the nature and density of defects in the sample shows that they are nano-scaled, preserving the regularity of the layer stacking mode, and limited to the formation of one- or two-units large stacking faults, associated with gliding mechanisms. Based on these observations, an original description of the LuFe2O4 ferrite structure, through puckered [LuO4](infinity) sandwiching [Fe-2](infinity) layers, is proposed. (C) 2013 Elsevier Masson SAS. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000324156200005 Publication Date (up) 2013-06-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1293-2558; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.811 Times cited 7 Open Access
Notes Approved Most recent IF: 1.811; 2013 IF: 1.679
Call Number UA @ lucian @ c:irua:111196 Serial 2276
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Author Lebedev, O.I.; Bals, S.; Van Tendeloo, G.; Snoeck, G.E.; Retoux, R.; Boudin, S.; Hervieu, M.
Title Mixed (Sr1-xCax)33Bi24Al48O141 fullerenoids: the defect structure analysed by (S)TEM techniques Type A1 Journal article
Year 2006 Publication International journal of materials research Abbreviated Journal Int J Mater Res
Volume 97 Issue 7 Pages 978-984
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (Sr1-xCax)(33)Bi-24,partial derivative Al48O141+3 partial derivative/2 fullerenoid solid solutions have been synthesized and the effect of partial substitution of Sr by Ca has been characterized by (scanning) transmission electron microscopy, applying different imaging methods. Most of the defects commonly observed in face centered cubic compounds, have also been observed in (Sr1-xCax)(33)Bi24-partial derivative Al48O141+3 partial derivative/2. Based on purely geometrical and topological models, structural presentations for the coherent twin boundaries and stacking faults have been constructed on the basis of complex spherical “Al84O210” units. The results are compared to defects observed in the crystallite fullerite C-60.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000239916700017 Publication Date (up) 2013-12-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-5282;2195-8556; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.681 Times cited 1 Open Access
Notes Approved Most recent IF: 0.681; 2006 IF: NA
Call Number UA @ lucian @ c:irua:60966 Serial 2091
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Author Malo, S.; Abakumov, A.M.; Daturi, M.; Pelloquin, D.; Van Tendeloo, G.; Guesdon, A.; Hervieu, M.
Title Sr21Bi8Cu2(CO3)(2)O-41, a Bi5+ Oxycarbonate with an Original 10L Structure Type A1 Journal article
Year 2014 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 53 Issue 19 Pages 10266-10275
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The layered structure of Sr21Bi8Cu2(CO3)(2)O-41 (Z = 2) was determined by transmission electron microscopy, infrared spectroscopy, and powder X-ray diffraction refinement in space group P6(3)/mcm (No. 194), with a = 10.0966(3)angstrom and c = 26.3762(5)angstrom. This original 10L-type structure is built from two structural blocks, namely, [Sr15Bi6Cu2(CO3)O-29] and [Sr6Bi2(CO3)O-12]. The Bi5+ cations form [Bi2O10] dimers, whereas the Cu2+ and C atoms occupy infinite tunnels running along (c) over right arrow. The nature of the different blocks and layers is discussed with regard to the existing hexagonal layered compounds. Sr21Bi8Cu2(CO3)(2)O-41 is insulating and paramagnetic.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000342856800039 Publication Date (up) 2014-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record
Impact Factor 4.857 Times cited Open Access
Notes Approved Most recent IF: 4.857; 2014 IF: 4.762
Call Number UA @ lucian @ c:irua:121115 Serial 3114
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