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  • 51.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Kremer, Reinhard
    Klaus, Hans-Henning
    Lemmens, Peter
    Crystal structure and magnetic properties of FeTe2O5X (X = Cl, Br) – a frustrated spin cluster compound with a new Te(IV) coordination polyhedron2006In: Journal of the American Chemical Society, ISSN 0002-7863, Vol. 128, p. 15469-15475Article in journal (Refereed)
  • 52.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Kremer, Reinhard
    Lemmens, Peter
    Crystal Structure and magnetic properties of Cu3(TeO3)2Br2 – a layered compound with a new Cu(II) coordination polyhedron2006In: Journal of Solid State Chemistry, ISSN 0022-4596, Vol. 178, no 6, p. 2024-2029Article in journal (Refereed)
  • 53.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Kremer, Reinhard
    Lemmens, Peter
    Crystal Structure, magnetic properties and ionic conductivity of CuSbTeO3Cl22003In: Solid State Sciences, ISSN 1293-2558, Vol. 5, no 11-12, p. 1411-1416Article in journal (Refereed)
  • 54.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Prester, Mladen
    Berger, Helmuth
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Drobac, Djuro
    Zivkovic, Ivica
    Crystal structure and magnetic properties of the new cobalt tellurite halide Co5(TeO3)4X2 (X = Cl, Br)2007In: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 9, no 3-4, p. 223-230Article in journal (Refereed)
    Abstract [en]

    Two new cobalt tellurite halides Co5(TeO3)4Cl2 and Co5(TeO3)4Br2 have been synthesized and found to be iso-structural with Ni5(TeO3)4X2 (X = Cl, Br). Co5(TeO3)4X2 crystallizes in the monoclinic system space group C2/c, and the Br-phase has the lattice parameters a = 20.440(1) Å, b = 5.2760(2) Å, c = 16.4710(7) Å, β = 124.790(5)°, and Z = 4. The crystal structures were solved from single-crystal X-ray data, R1 = 1.90 and 1.77, respectively, for the Cl- and Br-phases. The crystal structure is layered with only weak van der Waals' interactions in between the layers. The layers are built by large [Co5O16X2] groups consisting of five edge- and face-sharing Co-octahedra. Each group is connected to adjacent groups via corner sharing through common oxygen atoms as well as through [TeO3E] groups. Magnetic susceptibility measurements on oriented single crystals reveal pronounced anisotropy in a broad temperature range and clear signs of antiferromagnetic ordering at low temperatures. Anisotropic susceptibility of an iso-structural Ni-based compound was also studied and compared with the corresponding results of Co5(TeO3)4X2. Magnetic anisotropy is discussed in framework of single-ion anisotropy effects.

  • 55.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Prester, Mladen
    Berger, Helmuth
    Lin, Ping Hui
    Johnsson, Mats
    Drobac, Djuro
    Zivkovic, Ivica
    Crystal structure and magnetic properties of two new cobalt selenite halides: Co5(SeO3)4X2 (X=Cl, Br) 2007In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 180, no 3, p. 1051-1059Article in journal (Refereed)
    Abstract [en]

    Two new isostructural cobalt selenite halides Co5(SeO3)4Cl2 and Co5(SeO3)4Br2 have been synthesized. They crystallize in the triclinic system space group P−1 with the following lattice parameters for Co5(SeO3)4Cl2: a=6.4935(8) Å, b=7.7288(8) Å, c=7.7443(10) Å, α=66.051(11)°, β=73.610(11)°, γ=81.268(9)°, and Z=1. The crystal structures were solved from single-crystal X-ray data, R1=3.73 and 4.03 for Co5(SeO3)4Cl2 and Co5(SeO3)4Br2, respectively. The new compounds are isostructural to Ni5(SeO3)4Br2.

    Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range. The anisotropic susceptibility is quantitatively interpreted within the zero-field splitting schemes for Co2+ and Ni2+ ions. Sharp low-temperature susceptibility features, at TN=18 and 20 K for Co5(SeO3)4Cl2 and Co5(SeO3)4Br2, respectively, are ascribed to antiferromagnetic ordering in a minority magnetic subsystem. In isostructural Ni5(SeO3)4Br2 magnetically ordered subsystem represents a majority fraction (TN=46 K). Nevertheless, anisotropic susceptibility of Ni5(SeO3)4Br2 is dominated at low temperatures by a minority fraction, subject to single-ion anisotropy effects and increasing population of Sz=0 (singlet) ground state of octahedrally coordinated Ni2+.

  • 56. Berggren, Gustav
    et al.
    Huang, Ping
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Anderlund, Magnus F.
    Synthesis, Characterization and Reactivity Study of a New Penta-Coordinated Mn(II) Complex2009In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507, Vol. 36, no 1, p. 9-24Article in journal (Refereed)
    Abstract [en]

    A penta-coordinated Mn(II) compound [dqpMnCl2] (1) (dqp = 2,6-di-(8-quinoline-yl)-pyridine) has been synthesized and its X-ray crystallographic structure is reported here. Magnetic susceptibility measurements confirmed a high-spin Mn(II) (S = 5/2) center in 1. The X-band EPR spectrum of 1 in dimethylformamide solution exhibits widely distributed transitions in the spectral range from 0 to 700 mT with particularly well-resolved hyperfine lines due to the 55Mn (I = 5/2) nucleus. The abundance of highly resolved transition lines in the spectrum facilitated the electron paramagnetic resonance spectral simulation which revealed large zero-field splitting and g-anisotropies. When dissolved, 1 exists in equilibrium with a hexa-coordinated species, the latter probably resulting from disassociation of one chlorido-ligand allowing ligation of two solvent molecules. The redox behavior of 1 was studied and was compared to that of a structural analog for which water oxidation in the presence of a chemical oxidant has been shown. The results from water oxidation trials of 1 are discussed

  • 57. Berggren, Gustav
    et al.
    Kaynak, Filiz Betul
    Anderlund, Magnus F.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Åkermark, Björn
    Department of Organic Chemistry.
    Tetraethylammonium [12,12-diethyl-2,2,9,9-tetramethyl-1,4,7,10-tetraza-5,6-benzotridecane-3,8,11,13-tetra-one(4-)]oxidomanganate(V)2007In: Acta Crystallographica Section E, ISSN 1600-5368, Vol. E63, p. m2672-m2673Article in journal (Refereed)
  • 58. Berggren, Gustav
    et al.
    Thapper, Anders
    Anderlund, Magnus
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Two tetranuclear Mn-complexes as biomimetic models of the oxygen evolving complex in Photosystem II - A synthesis, characterisation and reactivity study2009In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 45, p. 10044-10054Article in journal (Refereed)
    Abstract [en]

    In this work we report the preparation of two metallamacrocyclic tetranuclear manganese(II) complexes, [L1(4)Mn(4)](ClO4)(4) and [L2(4)Mn(4)](ClO4)(4) where L1 and L2 are the anions of the heptadentate ligands 2-((2-(bis(pyridin-2-ylmethyl) amino) ethyl)(methyl) amino) acetic acid and 2-(benzyl(2-(bis(pyridin-2-ylmethyl) amino) ethyl) amino) acetic acid), respectively. The complexes have been fully characterized by ESI-MS, elemental analysis, single-crystal X-ray diffraction, magnetic susceptibility, and EPR spectroscopy. Electrochemical reactions as well as reactions with different chemical redox reagents have been performed and a reversible two electron oxidation per manganese ion has been identified. The reaction of [L1(4)Mn(4)](ClO4)(4) with oxone or cerium(IV) results in the evolution of oxygen which makes this system interesting for future studies in the search for a functional mimic of the oxygen evolving complex in Photosystem II.

  • 59.
    Berglund, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Physical Chemistry.
    Measurement and control of oxygen fugacity by means of gaseous oxygen buffers1983Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fundamental and practical aspects of oxygen buffering are reviewed, with particular reference to the gaseous oxygen buffer as a tool in elevated temperature oxide chemistry. An oxygen buffer capacity concept and a classification scheme for oxygen buffers are proposed; their application is demonstrated. The use, and limitations, of solid electrolyte oxygen gauges and pumps in the gaseous oxygen buffer context are examined; polarization and thermal asymmetry effects are calculated. Various forms of interaction between gaseous and condensed oxygen buffers are exemplified. The author's contribution to die methodology of circulating oxygen buffer atmospheres is summarized. The available data on the equilibrium thermodynamics of nickel + nickel oxide, a common reference buffer, are evaluated; its equilibrium oxygen fugacity appears to be slightly but significantly affected by direct contact with stabilized zirconia. Preparative work in the vanadium - oxygen and tungsten - oxygen systems is put into perspective against a brief structural background.

  • 60.
    Bergström, Lennart
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Allibert, C
    Kostorz, G
    Ågren, J
    International Symposium on Inorganic Interfacial Engineering 20062008In: Materials Science and Engineering A, Vol. 475, p. 1-376Article in journal (Refereed)
  • 61.
    Bergström, Lennart
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laakssonen, Aatto
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Self-assembled Materials2009In: Encyclopedia of Complexity and Systems Science / [ed] Robert A. Meyers, Berlin: Springer , 2009, p. 7931-7953Chapter in book (Other academic)
  • 62.
    Björling, Thomas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Synthesis and characterisation of Zintl hydrides2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The synthesis, structural characterisation and the properties of the Zintl hydrides AeE2H2 and AeAlSiH (Ae = Ba, Ca, Sr; E = Al, Ga, In, Si, Zn) are reported. The first hydride in this class of compounds is SrAl2H2 which was discovered under an experiment by Gingl, who hydrogenated SrAl2 at various temperatures. (Gingl et al, Journal of Alloys and Compounds 306 (2000) 127-132). The intention was to form alanates, e.g. AlH4-, by terminating the three dimensional four connected aluminium network in SrAl2. The new hydride, SrAl2H2, has a partially conserved aluminium network. The three dimensional anionic network in SrAl2 is reduced to two dimensions in the hydride, with aluminium bonded to both aluminium and hydrogen. This type of bonding configuration has not been observed before.

    The hydrogenation of SrAl2 is straight forward, 190 oC and 50 bar, compared to the difficult synthesis of alanates and alane, AlH3. The latter synthesises uses aluminium in its zero oxidation state in contrast to the synthesis of SrAl2H2 from SrAl2. (In the SrAl2-precursor aluminium is reduced by the electropositive metal to -I.) Thus, the discovery shows a different route to alanates by using precursors with aluminium in a reduced state. If SrAl2H2 is further hydrogenated at 250 oC the two dimensional network breaks and Sr2AlH7 forms.

    We wanted to investigate if SrAl2H2 was a singularity or if other similar compounds exist. We wanted to study how hydrogenation of precursors similar to the aluminide result in 1) new routes to compounds with high hydrogen content, as alanates, 2) to investigate how the E-H bond is affected as function of the network composition among different ternary hydrides, in particular BaAlxSi2-xHx, and choice of active metal.

    BaGa2H2 and SrGa2H2, two hydrides isostructural with SrAl2H2, were synthesized from its precursors BaGa2 and SrGa2. In addition three ternary hydrides BaAlSiH, CaAlSiH and SrAlSiH were manufactured from their related AeAlSi precursors.

    All powders were characterized by neutron and x-ray diffraction methods.

    An increased stability towards water/moisture compared to ordinary saline hydrides was noticed, especially for the ternary hydrides. Heat stability was measured with DSC (differential scanning calorimetry). The hydrides BaGa2H2 and SrGa2H2 decompose around 300 oC at 1 atm. This is similar to isostructural SrAl2H2. The ternary hydrides BaAlSiH and SrAlSiH decompose at 600 oC, at 1 atm, which is the highest noticed temperature for compounds with Al-H bonds. Inelastic neutron scattering experiments showed that these hydrides Al-H and Sr-H bonds are really weak, even weaker then the Al-H interactions in alanates and alanes. These hydrides are probably stabilized be their lattices. The electric properties among the ternary hydrides were measured with IR-spectroscopy (diffuse reflectance). The ternary hydrides, AeAlSiH, are indirect semi conductors. BaGa2H2 and SrGa2H2 are conductors. The ternary hydrides, AeAlxSi2-xHx, may have adjustable band gaps, which we were not able to determine.

    This work is leading into a new research area within the field of metal hydrides.

  • 63.
    Blomqvist, Helen
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Magnesium ions stabilizing solid-state transition metal hydrides2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is focused on hydrides containing first-row transition metal–hydrido complexes counterbalanced by magnesium. In particular, fundamental properties of the promising hydrogen storage material Mg2NiH4 have been studied. Results presented in the thesis provide detailed knowledge of the electronic structure and bonding mechanisms and are of significance for improving the hydrogen desorption process of complex transition metal hydrides in general.Two competing stabilization mechanisms in Mg2NiH4 have been identified; presence of microtwinning in the structure and the extra Mg added to the melt-cast Mg2Ni starting alloys, which acts as stabilizing dopant in the Mg2NiH4 system. When eliminating both stabilization mechanisms, the hydrogen release pressure was doubled at 453 K. Mg2NiH4 behaves like a heavily doped semiconductor at lower temperatures, but the conductivity is counteracted by the introduction of microtwinning in the structure at elevated temperatures, which makes the hydride non-conducting at » 400 K. The conductivity can be regained by reducing the amount of microtwinning with an applied mechanical pressure. Size, coordination and type of cation framework have decisive roles in determining the structure type of complex metal hydrides, as shown by ab initio total-energy calculations. Compared to the rich variety of Pd-based complex hydrides, the few Ni hydrido complexes hitherto found only contain Mg2+, solely or in combination with Ca2+, Sr2+, Yb2+, Eu2+ or La3+. Apparently the rather weak Ni–H bond needs a small and polarizing cation, e.g. Mg2+, to be stabilized in the solid state. The rather strong Mg–H interaction makes Mg2NiH4 a hybrid of ionic and complex transition metal hydride. This stabilization mechanism where electron density is redistributed by the polarizable hydrido ligand explains why Mg2NiH4 is very sensitive to disturbances of the crystal ordering, e.g. doping and ball milling, which profoundly affect stability, conductivity, color, structure and phasetransition conditions. Mg2+ also has the ability to stabilize Mn hydrido complexes, as observed in the novel Mg3MnH~6 compound, synthesized at GPa pressure in the solid state.

  • 64.
    Bonneau, Charlotte
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sanchez-Smith, Rebeca
    Guo, Bing
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zhang, Daliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Inge, Andrew Kentaro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Edén, Mattias
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Open-Framework Germanate Built from the Hexagonal Packing of Rigid Cylinders2009In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 48, no 21, p. 9962-9964Article in journal (Refereed)
    Abstract [en]

    We present a novel open-framework oxide material constructed from Ge10(O,OH)28 (Ge10) oxide clusters prepared via a nonsurfactant route. The material shows two distinct pore windows of 9.43 and 4.65 Å and a low framework density structure of 12.7 Ge atoms per 1000 Å3. The topological study leads to the recognition of a newly observed trinodal 6,7-heterocoordinated net related to the 7-coordinated swh net. The structure displays large rigid cylinders showing features indicating a growth mechanism by hard-sphere packing of the inorganic moiety similar to that observed in mesoporous materials.

  • 65.
    Bonneau, Charlotte
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Tang, Liqiu
    Christensen, Kirsten E
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shi, Lei
    Open-framework germanates built from clusters – a study of nets and tilings2008In: Studies in Surface Science and Catalysis, Elsevier BV , 2008Chapter in book (Refereed)
  • 66.
    Borg, Astrid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Physical Chemistry.
    Spectroscopical and electron diffraction studies of some unsaturated chlorohydrocarbons1985Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with structural properties of unsaturated chlorhydrocarbons of general formulas C^H^Cl, C^H^Cl and as studied by microwave spectroscopy, electron diffraction and vibrational spectroscopic methods. The two former methods both give values of molecular structure parameters in gas phase, but due to different averages of the thermal motion the structures arrived at are not comparable. The link between the different structures is provided for by a reliable force field, derived from the observed fundamental vibrational energy transitions, on which the emphasis of this work lies.

    The vibrational spectra of cis- and trans-monochlorobutadiene, cis, cis-, cis.trans- and trans,trans-dichlorobutadiene and of 4-chlorobuten- 3-yne were recorded in the medium and far infrared region and in Raman.

    Assignment of the spectra was possible. Band contours of the spectra in the gaseous state as well as Raman polarization data were taken into account. Normal coordinate analyses were carried out with the help of a computer program, in which the estimated force field of the simplified valence type of each molecule, constructed of parameter values from similar molecules, is fitted to the observed frequencies. For the monochlorobutadienes, force fields of 22 diagonal and 8 off-diagonal elements, of which 17 values were kept fixed, succeeded in reproducing the observed fundamental frequencies. For the disubstituted butadienes, force fields of 29 parameters, 7 of which off-diagonal, were employed. Root-mean-square amplitudes of vibration and perpendicular amplitude correction coefficients for subsequent use in the refinement of electron diffraction data were also calculated.

    In the chlorobutenyne case, the force field consisted of 27 parameters, 10 off-diagonal elements. The agreement between the observed frequencies and those calculated with the force field was very good.

  • 67. Boström, Magnus
    et al.
    Lind, Hanna
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lidin, Sven
    Niewa, Rainer
    Grin, Yuri
    Synthesis, crystal structure, phase relations and ELF analysis of the novel Nowotny chimney ladder compound ZrBi1.62Manuscript (Other academic)
  • 68.
    Bryntse, Ingrid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Inorganic Chemistry.
    Studies of systems related to high-Tc superconductors by electron microscopy and X-ray powder diffraction1992Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    New cuprate systems related to high temperature superconductors have been investigated and are reviewed. The synthesized samples have been studied mainly by transmission electron microscopy, energy-dispersive spectrometry and X-ray powder diffraction, in order to determine composition and structure of the formed phases.

    The following compounds were studied: Bi14Cu10Nb16O7 and Bit 7Cuo.2Ti2.006.8, both of cubic pyrochlore-type structure; BiNbs.4015, a tetragonal tungsten bronze type compound; Bi2/3Cu3Ti4012, a perovskite-related phase; Ba4CuYW2012, with a perovskite based unit cell; LaSrCuGaOs and LaCaCuGaOs, both of brownmillerite type and some related phases obtained by aliovalent substitution; R2Hg04 (R = La, Nd, Sm, Eu and Gd), with a new type of structure; and HgBa^RCugOy (R = La, Nd, Eu, Eu+Ca, Gd, Dy and Y), new "Hg-1212" type phases with a structure related to that of the thallium superconductor TlBa2CaCu207.

    The structural features of these compounds of relevance to superconductivity are also discussed.

  • 69. Bunta, Juraj
    et al.
    Dahlberg, Martin
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Eriksson, Leif
    Korolev, Nikolai
    Laaksonen, Aatto
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lohikoski, Raimo
    Lyubartsev, Alexander
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Pinak, Miroslav
    Schyman, Patric
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Solvating, manipulating, damaging, and repairing DNA in a computer2007In: International Journal of Quantum Chemistry, Vol. 107, p. 279-291Article in journal (Refereed)
  • 70.
    Burkhardt, Anja
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Widmalm, Göran
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Cumpstey, Ian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    (Z)-1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose O-benzyloxime2009In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. E65, no Part 3, p. o633-o633Article in journal (Refereed)
  • 71. Cadars, Sylvian
    et al.
    Mifsud, Nicolas
    Lesage, Anne
    Epping, Jan Dirk
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Chmelka, Bradley F
    Emsley, Lyndon
    Dynamics and disorder in surfactant-templated silicate layers studied by solid-state NMR dephasing times and correlated line shapes2008In: Journal of Physical Chemistry C, ISSN 1932-7447, Vol. 112, no 25, p. 9145-9154Article in journal (Refereed)
    Abstract [en]

    Surfactant-templated layered silicates are shown to possess complex compositional, structural, and dynamic features that manifest rich and interrelated order and disorder at molecular length scales. Temperature-dependent 1D and 2D solid-state Si-29 NMR measurements reveal a chemical-exchange process involving the surfactant headgroups that is concomitant with reversible broadening of Si-29 NMR line shapes under magic-angle-spinning (MAS) conditions at temperatures in the range 205-330 K. Specifically, the temperature-dependent changes in the Si-29 transverse dephasing times T-2' can be quantitatively accounted for by 2-fold reorientational dynamics of the surfactant headgroups. Variable-temperature analyses demonstrate that the temperature-dependent Si-29 shifts, peak broadening, and 2D Si-29{Si-29} correlation NMR line shapes are directly related to the freezing of the surfactant headgroup dynamics, which results in local structural disorder within the silicate framework.

  • 72.
    Cai, Yanbing
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Synthesis and Characterization of Nitrogen-rich Calcium α-Sialon Ceramics2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, a synthesis concept has been developed, which uses nitrogen-rich liquid phases for sintering of Ca-α-sialon ceramics. First, keeping the Si/Al ratios constant, the effects of N/O ratio on the properties and microstructure were investigated through a liquid phase sintering process. Second, nitrogen-rich Ca-α-sialon ceramics, with nominal compositions: CaxSi12-2xAl2xN16, x < 2.0, was synthesized and characterized. Third, mechanical and thermal properties of nitrogen-rich Ca-α-sialons were investigated in terms of high temperature deformation resistance,reaction mechanism, phase stability and oxidation resistance, and further correlated to their phase assemblage and microstructure observation.

    It has been found that increasing the N/O and Ca/Al ratio simultaneously in the materials could result in development of a microstructure with well shaped, high-aspect-ratio Ca-α-sialon grains, and an improvement in both toughness and hardness.

    For the nitrogen-rich Ca-α-sialon, mono-phasic α-sialon ceramics were obtained for 0.51 ≤ x ≤ 1.32. The obtained Ca-α-sialon ceramics with elongated-grain microstructures show a combination of high hardness and high fracture toughness. Compared with the oxygen-rich Ca-α-sialons, the nitrogen-rich Ca-α-sialons exhibited approximately 150 oC higher deformation onset temperatures and decent properties even after the deformation.

    The α-sialon phase was first observed at 1400 oC, however the phase pure Ca-α-sialon ceramics couldn’t be obtained until 1800 oC. The nitrogen-rich Ca-α-sialons were thermal stable, no phase transformation observed in the temperatures range1400-1600 oC. In general, mixed α/β-sialon showed better oxidation resistance than pure α-sialon in the low temperature range (1250-1325 oC), while α-sialons with compositions located at α/β-sialon border-line showed significant weight gains over the entire temperature range (1250-1400 oC).

  • 73.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Höche, Thomas
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Super plastic deformation of nitrogen-rich Ca-a-Sialon ceramics2008In: Materials Science and Engineering A, Vol. 475, p. 81-86Article in journal (Refereed)
  • 74.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Shen, Zhijian
    Esmaeilzadeh, Saeid
    Nitrogen-Rich α-Sialons Stabilized by Y, Yb, and Nb CationsManuscript (Other academic)
  • 75.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Nygren, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Thermal Properties of Nitrogen-Rich Ca-α-Sialons2009In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 29, no 16, p. 3409-3417Article in journal (Refereed)
    Abstract [en]

    Nitrogen-rich Ca-α-Sialon (CaxSi12−2xAl2xN16 with x = 0.2, 0.4, and 0.8, 1.2 and 1.6) ceramics were prepared from the mixtures of Si3N4, AlN and CaH2 powders in a hot press at 1800 °C using a pressure of 35 MPa and a holding time of 4 h, and then were investigated with respect to reaction mechanism, phase stability and oxidation resistance. In addition the sample with x = 1.6 was prepared in the temperature range 600–1800 °C using a pressure of 35 MPa and a holding time of 2 h. The α-Sialon phase was first observed at 1400 °C but the α-Si3N4 and AlN phases were still present at 1700 °C. Phase pure Ca-α-Sialon ceramics could not be obtained until the sintering temperature reached 1800 °C. The phase pure nitrogen-rich Ca-α-Sialon exhibited no phase transformation in the temperature range 1400–1600 °C. In general, mixed α/β-Sialon showed better oxidation resistance than pure α-Sialon in the low temperature range (1250–1325 °C), while α-Sialons with compositions located at α/β-Sialon border-line showed significant weight gains over the entire temperature range tested (1250–1400 °C). The phases formed upon oxidation were characterized by X-ray, SEM and TEM studies.

  • 76.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Superplastic deformation of nitrogen-rich Ca-?-sialon ceramics2007In: Materials Science and Engineering: AArticle in journal (Refereed)
  • 77.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Grins, Jekabs
    Esmaeilzadeh, Saeid
    Höche, Thomas
    Self-Reinforced Nitrogen-Rich Calcium-α-SiAlON Ceramics2007In: Journal of the American Ceramic Society, ISSN 0002-7820, Vol. 90, no 2, p. 608-613Article in journal (Refereed)
  • 78.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Höeche, T.
    Self-reinforced nitrogen-rich calcium-alpha-SiAlON ceramics2007In: Journal of the American Ceramic, Vol. 90, no 2, p. 608-613Article in journal (Refereed)
  • 79.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Saeid, Esmaeilzadeh
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sialon Ceramics Prepared by Using CaH2 as a Sintering Additive2008In: Journal of the American Ceramic Society, ISSN 0002-7820, Vol. 91, no 9, p. 2997-3004Article in journal (Refereed)
    Abstract [en]

    In developing elongated a-sialon grains, a nitrogen-rich liquidphase sintering method was introduced by using CaH2 as asintering aid, so as to vary the N/O ratio of the liquid phaseformed in the sintering process while keeping the Si/Al ratiosconstant. With increasing addition the phase contents changedfrom single b-sialon to dual b/a-sialons and to single Ca-a-sialon.At low N/O ratios the microstructures contained mainlyequiaxed b-sialon grains, and at high N/O ratios well facetedelongated Ca-a-sialon grains. The improved toughness(KIC57.8 MPa .m1/2) and hardness (HV10517.5 GPa) propertiescan be attributed to the formation of interlocked microstructures.High-temperature compressive deformation testsindicated that the deformation onset temperature is determinedmainly by the Si/Al and N/O ratios, whereas the deformationrate is affected by the microstructure, i.e., the morphology andamounts of elongated a-sialon grains and residual glass phase,especially for the sialons with low N/O ratios.

  • 80.
    Cai, Yanbing
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Zhijian
    Höche, Thomas
    Grins, Jekabs
    Esmaeilzadeh, Saeid
    Superplastic deformation of nitrogen-rich Ca-α-sialon ceramics2008In: Materials Science and Engineering: A, ISSN 09215093, Vol. 475, no 1-2, p. 81-86Article in journal (Refereed)
  • 81.
    Cantillana, T
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    (2S)-1,1-dichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethane2009In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 65(Pt 1), p. m9-m10Article in journal (Other academic)
    Abstract [en]

    In the mol­ecule of the title compound, [HgCl2(C10H9N3)], the HgII atom is four-coordinated in a distorted tetra­hedral configuration by two N atoms from the chelating di-2-pyridylamine ligand and by two Cl atoms. In the crystal structure, inter­molecular N—HCl hydrogen bonds link the mol­ecules into centrosymmetric dimers. There is a π–π contact between the pyridine rings [centroid–centroid distance = 3.896 (5) Å].

  • 82.
    Cantillana, T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Lindström, V.
    Eriksson, L.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Brandt, I.
    Bergman, Å.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Interindividual differences in o,p '-DDD enantiomer kinetics examined in Göttingen minipigs2009In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Chemosphere, Vol. 76, no 2, p. 167-172Article in journal (Refereed)
  • 83.
    cantillana, T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Lindström, V.
    Department of Environmental Toxicology, Uppsala University.
    Eriksson, L.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Brandt, I.
    Department of Environmental Toxicology, Uppsala University.
    Bergman, Å.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Interindividual differences in o,p'-DDD enantiomer kinetics examined in Göttingen minipigsManuscript (Other (popular science, discussion, etc.))
    Abstract [en]

    Five minipigs were given a single oral dose of a racemic mixture of o,p’-DDD (30 mg kg-1 b.w., EF = 0.49). Blood plasma and subcutaneous adipose tissue were collected for analysis, at different time-points over 180 d. At the end of the experiment also liver, kidney and brain tissue were collected. Low concentrations of o,p’-DDD still remained after 180 d in plasma (mean 0.5 ±0.3 ng g-1 f.w.) and in adipose tissue (mean 40 ±40 ng g-1 f..w.). The mean concentrations in liver and kidney were 500 ±300 pg g-1 f.w. and 90 ±50 pg g-1 f.w. respectively. The enantiomers of o,p’-DDD were isolated by HPLC and the absolute configuration of the enantiomers were determined by X-ray crystallography and polarimetry as R-(+)-o,p’-DDD and S-(-)-o,p’-DDD. The enantiomer fractions (EFs) of o,p’-DDD were determined in plasma, adipose tissue and kidney using GC/ECD equipped with a chiral column. The EFs of o,p’-DDD in the individual minipigs showed large variability, ranging from 0.2-0.6 after 24 h in plasma and from 0.2-0.7 after 90 d in adipose tissue. Hence in two of the minipigs, the S-(-)-o,p’-DDD enantiomer was dominating while the other enantiomer, R-(+)-o,p’-DDD was dominating in three minipigs. We propose that a yet not identified factor related to polymorphism, regulating the metabolism and/or elimination of the enantiomeric o,p´-DDD, is responsible for the differences in enantiomeric retention of the compound in the minipigs.

  • 84. Capitani, G.C.
    et al.
    Oleynikov, P.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hovmöller, S.
    Mellini, M.
    A Practical Method to Detect and Correct for Lens Distortion in TEM2006In: Ultramicroscopy, Vol. 106, no 2, p. 66-74Article in journal (Refereed)
  • 85. Carlson, S.
    et al.
    Krogh Andersen, Anne Marie
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    High-Pressure Transitions of Trigonal α-ZrMo2O82000In: Physical review B Condensed matter and materials physics, ISSN 1098-0121, Vol. 61, no 17, p. 11209-11212.Article in journal (Refereed)
    Abstract [en]

    High-pressure synchrotron x-ray powder-diffraction studies show that trigonal α-ZrMo2O8 transforms to a monoclinic symmetry phase (δ-ZrMo2O8) at 1.06–1.11 GPa. The space group was determined to C2/m. A further high-pressure transition from the monoclinic δ to a triclinic ε phase occur at 2.0–2.5 GPa (space group P1 or P1¯). Both transformations are reversible. The volume compressibilities are similar for the α and δ phase, and five times lower for the ε phase.

  • 86.
    Carlson, Stefan
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    High pressure structural investigations using single crystal techniques: influence of pressure on Jahn-Teller distorted alkali manganese fluorides1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The results from high-pressure single-crystal X-ray diffraction studies of some ternary sodium transition metal fluorides are presented. The structures of NaMnF4, Na2MnF5, Na3MnF6 and Na3ScF6 have been investigated at high pressures, and in connection with these studies the Na5Mn3F14 structure has been investigated at ambient pressure. The compressibilities of these compounds are compared in terms of structural features such as atom packing, bulk moduli and Jahn-Teller effect. An introduction to high-pressure diffraction techniques using diamond anvil cells, DAC, is included.

    Bulk modulus data at pressures lower than 1 GPa show a much higher compressibility for NaMnF4 (B0 = 16 GPa) than for the other compounds (B0 = 46-56 GPa). A successively higher transition pressure for the collapse of the single crystals into polycrystalline specimens is observed in the series NaMnF4 (1.3 GPa), Na2MnF5 (3.0 GPa) and Na3MnF6 (4.0 GPa). This can be explained in terms of the different connectivity between corner-sharing MnF6 octahedra, since NaMnF4 contains two-dimensional layers of corner-connected octahedra, Na2MnF5 one-dimensional strings, and Na3MnF6 isolated octahedra.

    The transitions in the Mn3+-containing compounds (d4 ion) are shown to be dependent on structural changes due to the Jahn-Teller distortions of the MnF6 octahedra. Both X-ray diffraction and spectroscopic studies of Na3MnF6 show a reversible phase transition at 2.2 GPa, which implies a reorientation of the static prolate Jahn-Teller distortions of the co-ordination around Mn3+. The Na3ScF6 compound, containing Sc3+ (d0 ion), shows no such transitions. Preliminary investigations of NaMnF4, Na2MnF5 and Na3MnF6 by high-pressure powder techniques show that new polycrystalline phases are formed when the pressure is raised above that where the single crystals collapse.

  • 87.
    Carlsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Preparation and characterisation of refractory whiskers and selected alumina composites2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A whisker is a common name of single crystalline inorganic fibre of small dimensions, typically 0.5-1 μm in diameter and 20-50 μm in length. Whiskers are mainly used as reinforcement of ceramics. This work describes the synthesis and characterisation of new whisker types. Ti0.33Ta0.33Nb0.33CxN1-x, TiB2, B4C, and LaxCe1-xB6 have been prepared by carbothermal vapour–liquid–solid (CTR-VLS) growth mechanisms in the temperature range 900-1800°C, in argon or nitrogen. Generally, carbon and different suitable oxides were used as whisker precursors. The oxides reacted via a carbothermal reduction process. A halogenide salt was added to form gaseous metal halogenides or oxohalogenides and small amount of a transition metal was added to catalyse the whisker growth. In this mechanism, the whisker constituents are dissolved into the catalyst, in liquid phase, which becomes supersaturated. Then a whisker could nucleate and grow out under continuous feed of constituents.

    The syntheses of TiC, TiB2, and B4C were followed at ordinary synthesis conditions by means of mass spectrometry (MS), thermogravimetry (TG), differential thermal analysis (DTA) and quenching. The main reaction starting temperatures and reaction time for the different mixtures was revealed, and it was found that the temperature inside the crucible during the reactions was up to 100°C below the furnace set-point, due to endothermic nature of the reactions. Quench experiments showed that whiskers were formed already when reaching the temperature plateau, but the yield increased fast with the holding time and reached a maximum after about 20-30 minutes. Growth models for whisker formation have been proposed.

    Alumina based composites reinforced by (2-5 vol.%) TiCnano and TiNnano and 25 vol.% of carbide, and boride phases (whiskers and particulates of TiC, TiN, TaC, NbC, (Ti,Ta)C, (Ti,Ta,Nb)C, SiC, TiB2 and B4C) have been prepared by a developed aqueous colloidal processing route followed by hot pressing for 90 min at 1700°C, 28 MPa or SPS sintering for 5 minutes at 1200-1600°C and 75 MPa. Vickers indentation measurements showed that the lowest possible sintering temperature is to prefer from mechanical properties point of view. In the TiNnano composites the fracture mode was typically intergranular, while it was transgranular in the SiCnano composites. The whisker and particulate composites have been compared in terms of e.g. microstructure and mechanical properties. Generally, additions of whiskers yielded higher fracture toughness compared to particulates. Composites of commercially available SiC whiskers showed best mechanical properties with a low spread but all the other whisker phases, especially TiB2, exhibited a great potential as reinforcement materials.

  • 88.
    Carlsson, Mats
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Alberius-Henning, Peter
    Johnsson, Mats
    Vapour-Liquid-Solid growth of TiB2 whiskers2002In: Journal of Materials Science, ISSN 0022-2461, Vol. 37, no 14, p. 2917-2925Article in journal (Refereed)
  • 89.
    Carlsson, Mats
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Garcia, Javier G.
    Synthesis and characterisation of boron carbide whiskers and thin elongated platelets2002In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 236, no 1-3, p. 466-476Article in journal (Refereed)
  • 90.
    Carlsson, Mats
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Garcia, Javier G.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Gulian, Armen
    Synthesis of LaxCe1-xB6 whiskers2004In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 40, no 11, p. 2991-2994Article in journal (Refereed)
  • 91.
    Carlsson, Mats
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Nygren, Mats
    Synthesis and characterisation of Ti0.33Ta0.33Nb0.33C and Ta0.33Ti0.33 Nb0.33CxN1-x whiskers1999In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 82, no 8, p. 1969-1976Article in journal (Refereed)
  • 92.
    Carlsson, Mats
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Pohl, Annika
    Preparation and Characterization of Alumina based TiNn and SiCn Composites2003In: Nanomaterials for Structural Applications / [ed] C. Berndt, T.E. Fischer, I. OvidÕko, G. Skandan, T. Tsakalakos, New York; North-Holland: Materials Research Society , 2003, p. 173-178Conference paper (Other academic)
  • 93.
    Castro, Vasco
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Solid-State NMR Characterization of Lipid Membranes2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with the study of lipid bilayer systems by solid-state nuclear magnetic resonance. Two-dimensional 1H-13C separated local field experiments under magic-angle spinning were employed to investigate structural and dynamical modifications of cell membranes, resulting from the addition of compounds with some biological relevance. For further interpretation of the segmental order obtained from the 2D experiments other methods, such as 31P-NMR, 2H-NMR and molecular dynamics simulations, were also employed.

    The work presented in this thesis can be divided into two parts. The first part refers to the setup of experimental conditions. Heating and hydration effects were addressed in order to define both the temperature of the system as well as the number of water molecules per lipid necessary to fully hydrate the bilayer. Application of this experimental setup to lipid membrane systems with biological relevance constitutes the second part. The interaction of monogalactosyl- diacylglycerol, the most abundant lipid on earth, with dimyristoylphosphatidylcholine, was studied, which resulted in a frustrated bilayer. Furthermore, small molecules of local anesthetics, with focus on lidocaine, were inserted in the model membrane with the purpose of understanding the influence of local anesthetics on lipid bilayers.

  • 94.
    Castro, Vasco
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Dvinskikh, Sergey V.
    Widmalm, G.
    Sandström, Dick
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Maliniak, Arnold
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    NMR Studies of Membranes Composed of Glycolipids and Phospholipids2007In: Biochimica et Biophysica Acta (BBA) – Biomembranes, Vol. 1768, p. 2432-2437Article in journal (Refereed)
  • 95.
    Castro, Vasco
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Dvinskikh, S.V.
    Widmalm, G.
    Sandström, D.
    NMR studies of membranes composed of glycolipids and phospholipids2007In: BBA – Biomembranes, no 1768, p. 2432-2437Article in journal (Refereed)
  • 96.
    Castro, Vasco
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Stevensson, Baltzar
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Dvinskikh, Sergey V.
    Division of Physical Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Högberg, Carl-Johan
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lyubartsev, Alexander P.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zimmermann, Herbert
    Department of Biophysics, Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany.
    Sandström, Dick
    Bruker BioSpin Scandinavia AB, Polygonvägen 79, SE-187 66 Täby, Sweden.
    Maliniak, Arnold
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    NMR investigations of interactions between anesthetics and lipid bilayers2008In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1178, no 11, p. 2604-2611Article in journal (Refereed)
    Abstract [en]

    Interactions between anesthetics (lidocaine and short chain alcohols) and lipid membranes formed by dimyristoylphosphatidylcholine (DMPC) were studied using NMR spectroscopy. The orientational order of lidocaine was investigated using deuterium NMR on a selectively labelled compound whereas segmental ordering in the lipids was probed by two-dimensional 1H–13C separated local field experiments under magic-angle spinning conditions. In addition, trajectories generated in molecular dynamics (MD) computer simulations were used for interpretation of the experimental results. Separate simulations were carried out with charged and uncharged lidocaine molecules. Reasonable agreement between experimental dipolar interactions and the calculated counterparts was observed. Our results clearly show that charged lidocaine affects significantly the lipid headgroup. In particular the ordering of the lipids is increased accompanied by drastic changes in the orientation of the P–N vector in the choline group.

  • 97. Chaim, Rachman
    et al.
    Kalina, Michael
    Shen, James Z.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Inorganic Chemistry.
    Transparent yttrium aluminum garnet (YAG) ceramics by spark plasma sintering2007In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 27, no 11, p. 3331-3337Article in journal (Refereed)
    Abstract [en]

    Commercial nanocrystalline yttrium aluminum garnet (nc-YAG) powders were used for fabrication of dense and transparent YAG by spark plasma sintering (SPS). Spherical 34 nm size particles were densified by SPS between 1200 and 1500 degrees C using 50 and 100 MPa pressures for 3, 6, and 9 min durations. Fully dense and transparent polycrystalline cubic YAG with micrometer grain size were fabricated at very moderate SPS conditions, i.e. 1375 degrees C, 100 MPa for 3 min. Increase in the SPS duration and pressure significantly increased the density especially at the lower temperature range. The observed microstructure is in agreement with densification by nano-grain rotation and sliding at lower densities, followed by curvature driven grain boundary migration and normal grain growth at higher densities. Residual nanosize pores at the grain boundary junctions are an inherent microstructure feature due to the SPS process.

  • 98. Chen, C. L.
    et al.
    Furusho, H.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mori, H.
    Silver nanowires with a monoclinic structure fabricated by a thermal evaporation method2009In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 20, p. 405605-Article in journal (Refereed)
    Abstract [en]

    Silver nanowires with a monoclinic structure (mono-Ag NWs) were fabricated by a thermal evaporation method for the first time. The crystal lattice parameters of the mono-Ag NWs were calculated using the UnitCell program. They are as follows: a = 0.303 nm, b = 1.140 nm, c = 0.292 nm, and β = 118.5◦. In situ annealing experiments revealed that the as-prepared mono-Ag NWs transited to fcc-Ag NWs during annealing at ∼1173 K for 60 s.

  • 99. Chen, Chun Lin
    et al.
    Furusho, Hirotoshi
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mori, Hirotaro
    In situ TEM observation of decomposition of high-purity sapphire2009In: Philosophical Magazine Letters, ISSN 0950-0839, E-ISSN 1362-3036, Vol. 89, no 2, p. 113-119Article in journal (Refereed)
    Abstract [en]

    The decomposition of agr-Al2O3 under 200 keV electron irradiation has been investigated by in situ high-resolution electron microscopy (HREM). It was confirmed that aluminium precipitated from agr-Al2O3 under 200 keV electron irradiation for less than 1 min over the temperature range from 700 to 1273 K. The electron dose rate was of the order of 1023 e m-2 s-1 and the vacuum level of the microscope was better than 10-6 Pa. The mechanisms of agr-Al2O3 decomposition were discussed based on two possible decomposition models: the thermally activated atom movement and the forced atom displacement

  • 100. Chen, Q.
    et al.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, S.
    Synthesis of silica mesoporous crystals with controlled structure and morphology using gemini surfactant2007In: Microporous and Mesoporous Materials, Vol. 105, p. 24-33Article in journal (Refereed)
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