toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Zhang, H.; Yang, J.-H.; Shpanchenko, R.V.; Abakumov, A.M.; Hadermann, J.; Clérac, R.; Dikarev, E.V. doi  openurl
  Title New class of single-source precursors for the synthesis of main group-transition metal oxides: heterobimetallic Pb-Mn \beta-diketonates Type A1 Journal article
  Year (down) 2009 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 48 Issue 17 Pages 8480-8488  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Heterometallic lead−manganese â-diketonates have been isolated in pure form by several synthetic methods that include solid-state and solution techniques. Two compounds with different Pb/Mn ratios, PbMn2(hfac)6 (1) and PbMn(hfac)4 (2) (hfac = hexafluoroacetylacetonate), can be obtained in quantitative yield by using different starting materials. Single crystal X-ray investigation revealed that the solid-state structure of 1 contains trinuclear molecules in which lead metal center is sandwiched between two [Mn(hfac)3] units, while 2 consists of infinite chains of alternating [Pb(hfac)2] and [Mn(hfac)2] fragments. The heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating-bridging fashion. Spectroscopic investigation confirmed the retention of heterometallic structures in solutions of non-coordinating solvents as well as upon sublimation-deposition procedure. Thermal decomposition of heterometallic diketonates has been systematically investigated in a wide range of temperatures and annealing times. For the first time, it has been shown that thermal decomposition of heterometallic diketonates results in mixed-metal oxides, while both the structure of precursors and the thermolysis conditions have a significant influence on the nature of the resulting oxides. Five different Pb−Mn oxides have been detected by X-ray powder diffraction when studying the decomposition of 1 and 2 in the temperature range 500−800 °C. The phase that has been previously reported as Pb0.43MnO2.18 was synthesized in the pure form by decomposition of 1, and crystallographically characterized. The orthorhombic unit cell parameters of this oxide, obtained by electron diffraction technique, have been subsequently refined using X-ray powder diffraction data. Besides that, a previously unknown lead−manganese oxide has been obtained at low temperature decomposition and short annealing times. The parameters of its monoclinically distorted unit cell have been determined. The EDX analysis revealed that this compound has a Pb/Mn ratio close to 1:4 and contains no appreciable amount of fluorine.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000269313500056 Publication Date 2009-08-04  
  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 28 Open Access  
  Notes Approved Most recent IF: 4.857; 2009 IF: 4.657  
  Call Number UA @ lucian @ c:irua:78486 Serial 2308  
Permanent link to this record
 

 
Author Lepoittevin, C.; Hadermann, J.; Malo, S.; Pérez, O.; Van Tendeloo, G.; Hervieu, M. pdf  doi
openurl 
  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 (down) 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 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  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Adkin, J.J.; Hayward, M.A. doi  openurl
  Title Topotactic reduction as a route to new close-packed anion deficient perovskites: structure and magnetism of 4H-BaMnO2+x Type A1 Journal article
  Year (down) 2009 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 131 Issue 30 Pages 10598-10604  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The anion-deficient perovskite 4H-BaMnO2+x has been obtained by a topotactic reduction, with LiH, of the hexagonal perovskite 4H-BaMnO3−x. The crystal structure of 4H-BaMnO2+x was solved using electron diffraction and X-ray powder diffraction and further refined using neutron powder diffraction (S.G. Pnma, a = 10.375(2) Å, b = 9.466(2) Å, c = 11.276(3) Å, at 373 K). The orthorhombic superstructure arises from the ordering of oxygen vacancies within a 4H (chch) stacking of close packed c-type BaO2.5 and h-type BaO1.5 layers. The ordering of the oxygen vacancies transforms the Mn2O9 units of face-sharing MnO6 octahedra into Mn2O7 (two corner-sharing tetrahedra) and Mn2O6 (two edge-sharing tetrahedra) groups. The Mn2O7 and Mn2O6 groups are linked by corner-sharing into a three-dimensional framework. The structures of the BaO2.5 and BaO1.5 layers are different from those observed previously in anion-deficient perovskites providing a new type of order pattern of oxygen atoms and vacancies in close packed structures. Magnetization measurements and neutron diffraction data reveal 4H-BaMnO2+x adopts an antiferromagnetically ordered state below TN ≈ 350 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000268644400056 Publication Date 2009-07-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 25 Open Access  
  Notes Approved Most recent IF: 13.858; 2009 IF: 8.580  
  Call Number UA @ lucian @ c:irua:77928 Serial 3681  
Permanent link to this record
 

 
Author Abakumov, A.M.; Hadermann, J.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Zhang, H.; Dikarev, E.V.; Shpanchenko, R.V.; Antipov, E.V. doi  openurl
  Title Original close-packed structure and magnetic properties of the Pb4Mn9O20 manganite Type A1 Journal article
  Year (down) 2009 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 182 Issue 8 Pages 2231-2238  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structure of the Pb4Mn9O20 compound (previously known as Pb0.43MnO2.18) was solved from powder X-ray diffraction, electron diffraction, and high resolution electron microscopy data (S.G. Pnma, a=13.8888(2) Å, b=11.2665(2) Å, c=9.9867(1) Å, RI=0.016, RP=0.047). The structure is based on a 6H (cch)2 close packing of pure oxygen h-type (O16) layers alternating with mixed c-type (Pb4O12) layers. The Mn atoms occupy octahedral interstices formed by the oxygen atoms of the close-packed layers. The MnO6 octahedra share edges within the layers, whereas the octahedra in neighboring layers are linked through corner sharing. The relationship with the closely related Pb3Mn7O15 structure is discussed. Magnetization measurements reveal a peculiar magnetic behavior with a phase transition at 52 K, a small net magnetization below the transition temperature, and a tendency towards spin freezing.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000269066400035 Publication Date 2009-06-12  
  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 5 Open Access  
  Notes The authors are grateful to Christoph Geibel for the help in magnetization measurements. A.Ts. acknowledges MPI CKS for hospitality and financial support during the stay. E.D. thanks the National Science Foundation (CHE-0718900) for financial support. This work was supported by the Russian Foundation of Basic Research (RFBR Grants 07-03-00664-a, 06-03-90168-a and 07-03-00890-a). The authors acknowledge financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Approved Most recent IF: 2.299; 2009 IF: 2.340  
  Call Number UA @ lucian @ c:irua:78935UA @ admin @ c:irua:78935 Serial 2529  
Permanent link to this record
 

 
Author Mandal, T.K.; Croft, M.; Hadermann, J.; Van Tendeloo, G.; Stephens, P.W.; Greenblatt, M. doi  openurl
  Title La2MnVO6 double perovskite: a structural, magnetic and X-ray absorption investigation Type A1 Journal article
  Year (down) 2009 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem  
  Volume 19 Issue 25 Pages 4382-4390  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The synthesis, electron diffraction (ED), synchrotron X-ray and neutron structure, X-ray absorption spectroscopy (XAS) and magnetic property studies of La2MnVO6 double perovskite are described. Analysis of the synchrotron powder X-ray diffraction data for La2MnVO6 indicates a disordered arrangement of Mn and V at the B-site of the perovskite structure. Absence of super-lattice reflections in the ED patterns for La2MnVO6 supports the disordered cation arrangement. Room temperature time-of-flight (TOF) neutron powder diffraction (NPD) data show no evidence of cation ordering, in corroboration with the ED and synchrotron studies (orthorhombic Pnma, a = 5.6097(3), b = 7.8837(5) and c = 5.5668(3) ; 295 K, NPD). A comparison of XAS analyses of La2TVO6 with T = Ni and Co shows T2+ formal oxidation state while the T = Mn material evidences a Mn3+ admixture into a dominantly Mn2+ ground state. V-K edge measurements manifest a mirror image behavior with a V4+ state for T = Ni and Co with a V3+ admixture arising in the T = Mn material. The magnetic susceptibility data for La2MnVO6 show ferromagnetic correlations; the observed effective moment, µeff (5.72 µB) is much smaller than the calculated moment (6.16 µB) based on the spin-only formula for Mn2+ (d5, HS) /V4+ (d1), supportive of the partly oxidized Mn and reduced V scenario (Mn3+/V3+).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000266989800015 Publication Date 2009-04-24  
  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 10 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:77367 Serial 3540  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Van Rompaey, S.; Mankevich, A.S.; Korsakov, I.E. doi  openurl
  Title Comment on ALaMn2O6-y (A = K, Rb): novel ferromagnetic manganites exhibiting negative giant magnetoresistance Type Editorial
  Year (down) 2009 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 21 Issue 9 Pages 2000-2001  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000265781000036 Publication Date 2009-04-14  
  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 4 Open Access  
  Notes Approved Most recent IF: 9.466; 2009 IF: 5.368  
  Call Number UA @ lucian @ c:irua:77055 Serial 411  
Permanent link to this record
 

 
Author Bharathy, M.; Gemmill, W.R.; Fox, A.H.; Darriet, J.; Smith, M.D.; Hadermann, J.; Remy, M.S.; zur Loye, H.-C. doi  openurl
  Title Synthesis and magnetic properties of rare earth ruthenates, Ln5Ru2O12 (Ln=Pr, Nd, SmTb) Type A1 Journal article
  Year (down) 2009 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 182 Issue 5 Pages 1164-1170  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Single crystals of Ln5Ru2O12 (Ln=Pr, Nd, SmTb) were grown out of either NaOH or KOH fluxes in sealed silver tubes. The crystals of all the phases were observed to be twinned as confirmed by TEM studies. The series crystallize in the C2/m monoclinic system with lattice parameters, a=12.4049(4)12.7621(6) Å, b=5.8414(2)5.9488(3) Å, c=7.3489(2)7.6424(4) Å, β=107.425(3)107.432(2)° and Z=2. The crystal structure is isotypic with the defect/disorder model of Ln5Re2O12 (Ln = Y, Gd) and consists of one dimensional edge shared RuO6 octahedral chains separated by a two dimensional LnOx polyhedral framework. Magnetic measurements indicate paramagnetic and antiferromagnetic behavior for Ln=Nd, SmGd and Ln=Tb, respectively.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000265893700027 Publication Date 2009-02-22  
  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 4 Open Access  
  Notes Approved Most recent IF: 2.299; 2009 IF: 2.340  
  Call Number UA @ lucian @ c:irua:77052 Serial 3433  
Permanent link to this record
 

 
Author Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. pdf  doi
openurl 
  Title Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides Type A1 Journal article
  Year (down) 2009 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem  
  Volume 19 Issue 18 Pages 2660-2670  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000265740600002 Publication Date 2009-02-04  
  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 9 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:77065 Serial 68  
Permanent link to this record
 

 
Author d' Hondt, H.; Hadermann, J.; Abakumov, A.M.; Kalyuzhnaya, A.S.; Rozova, M.G.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Antipov, E.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Synthesis, crystal structure and magnetic properties of the Sr2Al0.78Mn1.22O5.2 anion-deficient layered perovskite Type A1 Journal article
  Year (down) 2009 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 182 Issue 2 Pages 356-363  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A new layered perovskite Sr2Al0.78Mn1.22O5.2 has been synthesized by solid state reaction in a sealed evacuated silica tube. The crystal structure has been determined using electron diffraction, high-resolution electron microscopy, and high-angle annular dark field imaging and refined from X-ray powder diffraction data (space group P4/mmm, a=3.89023(5) Å, c=7.8034(1) Å, RI=0.023, RP=0.015). The structure is characterized by an alternation of MnO2 and (Al0.78Mn0.22)O1.2 layers. Oxygen atoms and vacancies, as well as the Al and Mn atoms in the (Al0.78Mn0.22)O1.2 layers are disordered. The local atomic arrangement in these layers is suggested to consist of short fragments of brownmillerite-type tetrahedral chains of corner-sharing AlO4 tetrahedra interrupted by MnO6 octahedra, at which the chain fragments rotate over 90°. This results in an averaged tetragonal symmetry. This is confirmed by the valence state of Mn measured by EELS. The relationship between the Sr2Al0.78Mn1.22O5.2 tetragonal perovskite and the parent Sr2Al1.07Mn0.93O5 brownmillerite is discussed. Magnetic susceptibility measurements indicate spin glass behavior of Sr2Al0.78Mn1.22O5.2. The lack of long-range magnetic ordering contrasts with Mn-containing brownmillerites and is likely caused by the frustration of interlayer interactions due to presence of the Mn atoms in the (Al0.78Mn0.22)O1.2 layers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000263124700022 Publication Date 2008-11-14  
  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 12 Open Access  
  Notes Iap Vi Approved Most recent IF: 2.299; 2009 IF: 2.340  
  Call Number UA @ lucian @ c:irua:72943 Serial 3450  
Permanent link to this record
 

 
Author Shpanchenko, R.V.; Tsirlin, A.A.; Hadermann, J.; Antipov, E.V. doi  openurl
  Title Synthesis and crystal structure of new titanyl phosphate Sr2TiO(PO4)2 Type A1 Journal article
  Year (down) 2008 Publication Russian chemical bulletin Abbreviated Journal Russ Chem B+  
  Volume 57 Issue 3 Pages 552-556  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract New strontium titanyl phosphate Sr2TiO(PO4)2 (1) was synthesized and characterized by X-ray powder diffraction, electron diffraction, high-resolution electron microscopy, and band structure calculations. Titanyl phosphate 1 is isostructural with vanadyl phosphate Sr2VO(PO4)2 and has a layered structure. The titanium atoms are shifted from the centers of the TiO6 octahedra and form short (1.74 Å) titanyl bonds. The structure of 1 is an unusual example of the disordered orientation of the chains formed by TiO6 octahedra in complex titanium phosphates.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000263566900015 Publication Date 2009-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1066-5285;1573-9171; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.529 Times cited 2 Open Access  
  Notes Approved Most recent IF: 0.529; 2008 IF: 0.469  
  Call Number UA @ lucian @ c:irua:73712 Serial 3423  
Permanent link to this record
 

 
Author d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Kalyuzhnaya, A.S.; Rozova, M.G.; Antipov, E.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Tetrahedral chain order in the Sr2Fe2O5 brownmillerite Type A1 Journal article
  Year (down) 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 20 Issue 22 Pages 7188-7194  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000261002200039 Publication Date 2008-10-25  
  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 64 Open Access  
  Notes Iap Vi Approved Most recent IF: 9.466; 2008 IF: 5.046  
  Call Number UA @ lucian @ c:irua:72945 Serial 3511  
Permanent link to this record
 

 
Author Herkelrath, S.J.C.; Saratovsky, I.; Hadermann, J.; Clarke, S.J. doi  openurl
  Title Fragmentation of an infinite ZnO2 square plane into discrete [ZnO2]2- linear units in the oxyselenide Ba2ZnO2Ag2Se2 Type A1 Journal article
  Year (down) 2008 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 130 Issue 44 Pages 14426-14427  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Analysis of single crystal X-ray diffraction, neutron powder diffraction, electron diffraction and Zn−K-edge EXAFS data show that Ba2ZnO2Ag2Se2 contains unusual isolated [ZnO2]2− moieties resulting from fragmentation of a ZnO2 infinite plane placed under tension.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000260533400037 Publication Date 2008-10-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 13 Open Access  
  Notes Approved Most recent IF: 13.858; 2008 IF: 8.091  
  Call Number UA @ lucian @ c:irua:72947 Serial 1273  
Permanent link to this record
 

 
Author Gillie, L.J.; Hadermann, J.; Hervieu, M.; Maignan, A.; Martin, C. doi  openurl
  Title Oxygen vacancy ordering in the double-layered Ruddlesden-Popper cobaltite Sm2BaCo2O7-\delta Type A1 Journal article
  Year (down) 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 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  
Permanent link to this record
 

 
Author Nikolaev, I.V.; d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Balagurov, A.M.; Bobrikov, I.A.; Sheptyakov, D.V.; Pomjakushin, V.Y.; Pokholok, K.V.; Filimonov, D.S.; Van Tendeloo, G.; Antipov, E.V. doi  openurl
  Title Crystal structure, phase transition, and magnetic ordering in perovskitelike Pb2-xBaxFe2O5 solid solutions Type A1 Journal article
  Year (down) 2008 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 78 Issue 2 Pages 024426,1-12  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000258190200085 Publication Date 2008-07-24  
  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 29 Open Access  
  Notes Iap Vi Approved Most recent IF: 3.836; 2008 IF: 3.322  
  Call Number UA @ lucian @ c:irua:70580 Serial 576  
Permanent link to this record
 

 
Author Shpanchenko, R.V.; Tsirlin, A.A.; Kondakova, E.S.; Antipov, E.V.; Bougerol, C.; Hadermann, J.; Van Tendeloo, G.; Sakurai, H.; Takayama-Muromachi, E. doi  openurl
  Title New germanates RCrGeO5 (R=NdEr, Y): synthesis, structure, and properties Type A1 Journal article
  Year (down) 2008 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 181 Issue 9 Pages 2433-2441  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The new complex germanates RCrGeO5 (R=NdEr, Y) have been synthesized and investigated by means of X-ray powder diffraction, electron microscopy, magnetic susceptibility and specific heat measurements. All the compounds are isostructural and crystallize in the orthorhombic symmetry, space group Pbam, and Z=4. The crystal structure of RCrGeO5, as refined using X-ray powder diffraction data, includes infinite chains built by edge-sharing Cr+3O6 octahedra with two alternating Cr−Cr distances. The chains are combined into a three-dimensional framework by Ge2O8 groups consisting of two edge-linked square pyramids oriented in opposite directions. The resulting framework contains pentagonal channels where rare-earth elements are located. Thus, RCrGeO5 germanates present new examples of RMn2O5-type compounds and show ordering of Cr+3 and Ge+4 cations. Electron diffraction as well as high-resolution electron microscopy confirm the structure solution. Magnetic susceptibility data for R=Nd, Sm, and Eu are qualitatively consistent with the presence of isolated 3d (antiferromagnetically coupled Cr+3 cations) and 4f (R+3) spin subsystems in the RCrGeO5 compounds. NdCrGeO5 undergoes long-range magnetic ordering at 2.6 K, while SmCrGeO5 and EuCrGeO5 do not show any phase transitions down to 2 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000259415800047 Publication Date 2008-06-06  
  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 6 Open Access  
  Notes Approved Most recent IF: 2.299; 2008 IF: 1.910  
  Call Number UA @ lucian @ c:irua:72948 Serial 2314  
Permanent link to this record
 

 
Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Antipov, E.V. pdf  doi
openurl 
  Title Chemistry and structure of anion-deficient perovskites with translational interfaces Type A1 Journal article
  Year (down) 2008 Publication Journal of the American Ceramic Society Abbreviated Journal J Am Ceram Soc  
  Volume 91 Issue 6 Pages 1807-1813  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Columbus, Ohio Editor  
  Language Wos 000256410700010 Publication Date 2008-04-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7820;1551-2916; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.841 Times cited 39 Open Access  
  Notes Approved Most recent IF: 2.841; 2008 IF: 2.101  
  Call Number UA @ lucian @ c:irua:70088 Serial 355  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Nikolaev, I.V.; Antipov, E.V.; Van Tendeloo, G. doi  openurl
  Title Local structure of perovskite-based “Pb2Fe2O5 Type A1 Journal article
  Year (down) 2008 Publication Solid state sciences Abbreviated Journal Solid State Sci  
  Volume 10 Issue 4 Pages 382-389  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000256200200003 Publication Date 2008-01-20  
  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 29 Open Access  
  Notes Approved Most recent IF: 1.811; 2008 IF: 1.742  
  Call Number UA @ lucian @ c:irua:69289 Serial 1832  
Permanent link to this record
 

 
Author Mandal, T.K.; Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Croft, M.; Greenblatt, M. pdf  doi
openurl 
  Title Synthesis, crystal structure, and magnetic properties of Srl.31Co0.63Mn0.3703: a reivative of the incommensurate composite hexagonal perovskite structure Type A1 Journal article
  Year (down) 2007 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 19 Issue 25 Pages 6158-6167  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000251422000019 Publication Date 2007-11-13  
  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 5 Open Access  
  Notes Approved Most recent IF: 9.466; 2007 IF: 4.883  
  Call Number UA @ lucian @ c:irua:67597 Serial 3449  
Permanent link to this record
 

 
Author Tsirlin, A.A.; Shpanchenko, R.V.; Antipov, E.V.; Bougerol, C.; Hadermann, J.; Van Tendeloo, G.; Schnelle, W.; Rosner, H. doi  openurl
  Title Spin ladder compound Pb0.55Cd0.45V2O5: synthesis and investigation Type A1 Journal article
  Year (down) 2007 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 76 Issue 10 Pages 104429,1-7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000249786300074 Publication Date 2007-09-25  
  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 1 Open Access  
  Notes Approved Most recent IF: 3.836; 2007 IF: 3.172  
  Call Number UA @ lucian @ c:irua:65594 Serial 3091  
Permanent link to this record
 

 
Author Tarakina, N.V.; Nikulina, E.A.; Hadermann, J.; Kellerman, D.G.; Tyutunnik, A.P.; Berger, I.F.; Zubkov, V.G.; Van Tendeloo, G. pdf  doi
openurl 
  Title Crystal structure and magnetic properties of complex oxides Mg4-xNixO9, 0\leq x\leq4 Type A1 Journal article
  Year (down) 2007 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 180 Issue 11 Pages 3180-3187  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In the Mg4−xNixNb2O9 (0x4) system two ranges of solid solution have been found. One of the solid solutions has a corundum-related structure type (space group ); the second one adopts the II-Ni4Nb2O9 structure type (space group Pbcn). The unit cell constants and atomic positions have been determined and refined using neutron powder diffraction data. Electron diffraction and high-resolution transmission electron microscopy (HRTEM) from MgNi3Nb2O9 crystals identify the presence of planar defects and the intergrowth of several (structurally related) phases. The magnetic susceptibility of Mg3NiNb2O9, measured in the temperature range T=2300 K, shows no indications of magnetic ordering at low temperatures, while for MgNi3Nb2O9 there is a magnetic ordering at temperatures below 45.5 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000260636200025 Publication Date 2007-09-15  
  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 3 Open Access  
  Notes Belgium Science Policy Approved Most recent IF: 2.299; 2007 IF: 2.149  
  Call Number UA @ lucian @ c:irua:72944 Serial 559  
Permanent link to this record
 

 
Author Hyett, G.; Barrier, N.; Clarke, S.J.; Hadermann, J. doi  openurl
  Title Topotactic oxidative and reductive control of the structures and properties of layered manganese oxychalcogenides Type A1 Journal article
  Year (down) 2007 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 129 Issue 36 Pages 11192-11201  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000249372400055 Publication Date 2007-08-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 12 Open Access  
  Notes Approved Most recent IF: 13.858; 2007 IF: 7.885  
  Call Number UA @ lucian @ c:irua:65592 Serial 3680  
Permanent link to this record
 

 
Author Alekseeva, A.M.; Abakumov, A.M.; Chizhov, P.S.; Leithe-Jasper, A.; Schnelle, W.; Prots, Y.; Hadermann, J.; Antipov, E.V.; Grin, Y. pdf  doi
openurl 
  Title Ternary magnesium rhodium boride Mg2Rh1-xB6+2x with a modified Y2ReB6-type crystal structure Type A1 Journal article
  Year (down) 2007 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 46 Issue 18 Pages 7378-7386  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000248984500026 Publication Date 2007-08-09  
  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 12 Open Access  
  Notes Approved Most recent IF: 4.857; 2007 IF: 4.123  
  Call Number UA @ lucian @ c:irua:65595 Serial 3510  
Permanent link to this record
 

 
Author Yan, L.; Niu, H.; Bridges, C.A.; Marshall, P.A.; Hadermann, J.; Van Tendeloo, G.; Chalker, P.R.; Rosseinsky, M.J. pdf  doi
openurl 
  Title Unit-cell-level assembly of metastable transition-metal oxides by pulsed-laser deposition Type A1 Journal article
  Year (down) 2007 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit  
  Volume 46 Issue 24 Pages 4539-4542  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000247500600026 Publication Date 2007-05-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1433-7851;1521-3773; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 11.994 Times cited 16 Open Access  
  Notes Approved Most recent IF: 11.994; 2007 IF: 10.031  
  Call Number UA @ lucian @ c:irua:65593 Serial 3812  
Permanent link to this record
 

 
Author Mazo, G.N.; Savvin, S.N.; Abakumov, A.M.; Hadermann, J.; Dobrovol'skii, Y.A.; Leonova, L.S. doi  openurl
  Title Lanthanum-strontium cuprate as a promising cathodic matreila for solid oxide fuel cells Type A1 Journal article
  Year (down) 2007 Publication Russian journal of electrochemistry Abbreviated Journal Russ J Electrochem+  
  Volume 43 Issue 4 Pages 436-442  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000246338500010 Publication Date 2007-05-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1023-1935;1608-3342; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.828 Times cited 8 Open Access  
  Notes Approved Most recent IF: 0.828; 2007 IF: 0.263  
  Call Number UA @ lucian @ c:irua:62062 Serial 1777  
Permanent link to this record
 

 
Author Hadermann, J.; Pérez, O.; Créon, N.; Michel, C.; Hervieu, M. doi  openurl
  Title The (3 + 2)D structure of oxygen deficient LaSrCuO3.52 Type A1 Journal article
  Year (down) 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 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  
Permanent link to this record
 

 
Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Kovba, M.L.; Skolis, Y.Y.; Mudretsova, S.N.; Antipov, E.V.; Volkova, O.S.; Vasiliev, A.N.; Tristan, N.; Klingeler, R.; Büchner, B. pdf  doi
openurl 
  Title [SrF0.8(OH)0.2]2.526[Mn6O12]: columnar rock-salt fragments inside the todorokite-type tunnel structure Type A1 Journal article
  Year (down) 2007 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 19 Issue 5 Pages 1181-1189  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000244467800035 Publication Date 2007-02-13  
  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 9 Open Access  
  Notes Iap V-1 Approved Most recent IF: 9.466; 2007 IF: 4.883  
  Call Number UA @ lucian @ c:irua:62525 Serial 3561  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; d' Hondt, H.; Kalyuzhnaya, A.S.; Rozova, M.G.; Markina, M.M.; Mikheev, M.G.; Tristan, N.; Klingeler, R.; Büchner, B.; Antipov, E.V. pdf  doi
openurl 
  Title Synthesis and crystal structure of the Sr2Al1.07Mn0.93O5 brownmillerite Type A1 Journal article
  Year (down) 2007 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem  
  Volume 17 Issue 7 Pages 692-698  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000244085100016 Publication Date 2006-12-15  
  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 31 Open Access  
  Notes Iap V-1 Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:62061 Serial 3430  
Permanent link to this record
 

 
Author Panin, R.V.; Khasanova, N.R.; Abakumov, A.M.; Schnelle, W.; Hadermann, J.; Antipov, E.V. doi  openurl
  Title Crystal structure and properties of the Na1-xRu2O4 phase Type A1 Journal article
  Year (down) 2006 Publication Russian chemical bulletin Abbreviated Journal Russ Chem B+  
  Volume 55 Issue 10 Pages 1717-1722  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000245091400003 Publication Date 2007-03-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1066-5285;1573-9171; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.529 Times cited 5 Open Access  
  Notes Approved Most recent IF: 0.529; 2006 IF: 0.505  
  Call Number UA @ lucian @ c:irua:63810 Serial 566  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Gillie, L.J.; Martin, C.; Hervieu, M. pdf  doi
openurl 
  Title Coupled cation and charge ordering in the CaMn306 tunnel structure Type A1 Journal article
  Year (down) 2006 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 18 Issue 23 Pages 5530-5536  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000241808600021 Publication Date 2006-10-15  
  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 33 Open Access  
  Notes Iap V-1 Approved Most recent IF: 9.466; 2006 IF: 5.104  
  Call Number UA @ lucian @ c:irua:61374 Serial 534  
Permanent link to this record
 

 
Author Créon, N.; Pérez, O.; Hadermann, J.; Klein, Y.; Hébert, S.; Hervieu, M.; Raveau, B. doi  openurl
  Title Double modulation and microstructure of the thermoelectric misfit compound \left[Ca2-yLnyCu0.7+yCo1.3-yO4\right]\left[CoO2\right]b_{1/b2} (Ln = Pr, Y and 0\leq y\leq1/3) Type A1 Journal article
  Year (down) 2006 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 18 Issue 22 Pages 5355-5362  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000241492900033 Publication Date 2006-10-10  
  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 Approved Most recent IF: 9.466; 2006 IF: 5.104  
  Call Number UA @ lucian @ c:irua:61846 Serial 755  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: