Now showing items 1-20 of 30

  • Sønsteby, Henrik Hovde; Nilsen, Ola; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    Thin films of complex alkali oxides are frequently investigated due to the large range of electric effects that are found in this class of materials. Their piezo- and ferroelectric properties also place them as sustainable ...
  • Østreng, Erik; Sønsteby, Henrik H.; Sajavaara, Timo; Nilsen, Ola; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / Published version; Peer reviewed, 2013)
    The ferroelectric and electro-optical properties of LiNbO3 make it an important material for current and future applications. It has also been suggested as a possible lead-free replacement for present PZT-devices. The ...
  • Østreng, Erik; Sønsteby, Henrik H.; Øien, Sigurd; Nilsen, Ola; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Thin films of sodium and potassium oxides have for the first time been deposited using atomic layer deposition. Sodium and potassium complexes of tert-butanol, trimethylsilanol and hexamethyldisilazide have been evaluated ...
  • Zacharaki, Eirini; Kalyva, Maria; Fjellvåg, Helmer; Sjåstad, Anja O (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
  • Fjellvåg, Helmer; Karen, Pavel; Kjekshus, Arne; Kofstad, Per; Norby, Truls Eivind (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 1988)
    © 1988 Acta Chemica Scandinavica
  • Sottmann, Jonas; Di Michiel, Marco; Fjellvåg, Helmer; Malavasi, Lorenzo; Margadonna, Serena; Vajeeston, Ponniah; Vaughan, Gavin B M; Wragg, David (Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)
    To improve lithium and sodium ion battery technology, it is imperative to understand how the properties of the different components are controlled by their chemical structures. Operando structural studies give us some of ...
  • Fjellvåg, Helmer; Karen, Pavel (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 1994)
    © 1994 Acta Chemica Scandinavica
  • Fjellvåg, Helmer; Karen, Pavel; Kjekshus, Arne (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 1988)
    © 1988 Acta Chemica Scandinavica
  • Lundvall, Fredrik; Wragg, David; Dietzel, Pascal D.C.; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    In the title compound, C18H18O6, the biphenyl moiety is twisted with a dihedral angle of 29.11 (10)°. The carbometh­oxy groups form C-C-C-O torsion angles of -18.3 (3) and -27.7 (3)° with the attached rings, as a result ...
  • Karazhanov, Smagul; Ravindran, Ponniah; Fjellvåg, Helmer; Svensson, Bengt Gunnar (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2009)
    The electronic structure and optical properties of orthorhombic, monoclinic, and rhombohedral (corundum type) modifications of ZnSiO3, and of rhombohedral, tetragonal, and cubic (spinel type) modifications of Zn2SiO4 have ...
  • Vajeeston, Ponniah; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Li2FeSiO4 is an important alternative cathode for next generation Li-ion batteries due to its high theoretical capacity (330 mA h g−1). However, its development has faced significant challenges arising from structural ...
  • Bianchini, Federico; Fjellvåg, Helmer; Vajeeston, Ponniah (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    Sodium orthosilicates Na2MSiO4 (M = Mn, Fe, Co and Ni) have attracted much attention due to the possibility of exchanging two electrons per formula unit. They are also found to exhibit great structural stability due to a ...
  • Zacharaki, Eirini; Beato, Pablo; Tiruvalam, Ramchandra R; Andersson, Klas J.; Fjellvåg, Helmer; Sjåstad, Anja Olafsen (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    In the past few decades, advances in colloidal nanoparticle synthesis have created new possibilities for the preparation of supported model catalysts. However, effective removal of surfactants is a prerequisite to evaluate ...
  • Getz, Michael; Hansen, Per-Anders Stensby; Fjellvåg, Øystein Slagtern; Ahmed, Mohammed Amin Karim; Fjellvåg, Helmer; Nilsen, Ola (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    We demonstrate controlled deposition by atomic layer deposition of YVO4:Yb3+ thin films exhibiting an intense NIR emission under UV excitation after post-deposition annealing at 1000 °C. The samples are deposited using the ...
  • Karen, Pavel; Fjellvåg, Helmer; Braaten, O.; Kjekshus, Arne; Bratsberg, H. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 1990)
    © 1990 Acta Chemica Scandinavica
  • Andresen, A.F.; Fjellvåg, Helmer; Karen, Pavel; Kjekshus, Arne (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 1988)
    This research was originally published in Zeitschrift für Kristallographie - New Crystal Structures. © 1988 De Gruyter
  • Hansen, Per-Anders; Fjellvåg, Helmer; Finstad, Terje; Nilsen, Ola (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Luminescent europium titanium oxides (EuxTiyOz) have been deposited as thin films by atomic layer deposition (ALD) in the temperature range 225 to 375 °C with control of the stoichiometry from pure TiO2 to pure Eu2O3, and ...
  • Getz, Michael; Hansen, Per-Anders; Fjellvåg, Helmer; Nilsen, Ola (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    In the present contribution we assess the luminescent properties of amorphous europium titanium phosphate thin films. The films have been deposited by atomic layer deposition, using the precursor combinations Eu(thd)3 (thd ...
  • Getz, Michael; Hansen, Per-Anders; Ahmed, Mohammed Amin Karim; Fjellvåg, Helmer; Nilsen, Ola (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    UV to visible and near-infrared converting thin films of YbVO4 have been deposited by atomic layer deposition, using the precursor combinations Yb(thd)3 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and O3, and VO(thd)2 and ...
  • Lundvall, Fredrik; Wragg, David; Dietzel, Pascal D.C.; Fjellvåg, Helmer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    In the title compound, C9H9IO3, the mol­ecules are close to planar [maximum deviation from benzene ring plane = 0.229 (5) Å for the methyl carboxylate C atom] with the methyl groups oriented away from each other. In the ...