• A first-principles Study of epitaxial Interfaces between Graphene and GaAs 

      Marthinsen, Astrid (Master thesis, 2014)
      Epitaxial interfaces between graphene and GaAs(111) have been investigated through a first-principles study using density functional theory (DFT). The GaAs(111) surface at the interface is assumed to be 2x2 reconstructed ...
    • A new material for oxygen-permeable membranes 

      Adnan, Mohammed Mostafa (Master thesis, 2017)
      In this study, hexagonal YMnO3 doped with 15% Ti was used in the preparation of an asymmetric oxygen permeable membrane. Several different methods for the fabrication of the asymmetric membrane have been used, and the ...
    • A van der Waals Density Functional Study of MoO3 and Its Oxygen Vacancies 

      Inzani, Katherine; Grande, Tor; Vullum-Bruer, Fride; Selbach, Sverre Magnus (Journal article; Peer reviewed, 2016)
      The electronic structure of layered molybdenum trioxide MoO3 is highly sensitive to changes in oxygen stoichiometry as Mo6+ has an empty 4d shell. Applications of MoO3 are responsive to small changes in vacancy concentration, ...
    • Are MXenes Suitable as Cathode Material for Rechargeable Mg Batteries? 

      Kaland, Henning; Hadler-Jacobsen, Jacob; Fagerli, Frode Håskjold; Wagner, Nils Peter; Wang, Zhaohui; Selbach, Sverre Magnus; Vullum-Bruer, Fride; Wiik, Kjell; Schnell, Sondre Kvalvåg (Peer reviewed; Journal article, 2020)
      MXenes, a type of two-dimensional transition metal carbide/nitride, have received significant attention for electrochemical storage applications. With substantial capacities predicted for Mg ions, MXenes have been considered ...
    • Bi vacancy formation in BiFeO3 epitaxial thin films under compressive (001)-strain from first principles 

      Xia, Lu; Tybell, Thomas; Selbach, Sverre Magnus (Peer reviewed; Journal article, 2019)
      Point defects in BiFeO3 affect both structural and functional properties. To elucidate the role of single Bi vacancies and Bi–O vacancy pairs we investigate their stability and effect on structural and ferroelectric ...
    • Charged domain walls in improper ferroelectric hexagonal manganites and gallates 

      Småbråten, Didrik Rene; Meier, Quintin Noel; Skjærvø, Sandra Helen; Inzani, Katherine; Meier, Dennis; Selbach, Sverre Magnus (Journal article; Peer reviewed, 2018)
      Ferroelectric domain walls are attracting broad attention as atomic-scale switches, diodes and mobile wires for next-generation nanoelectronics. Charged domain walls in improper ferroelectrics are particularly interesting ...
    • Chemical expansion due to hydration of proton conducting perovskite oxide ceramics 

      Andersson, Annika KE; Selbach, Sverre Magnus; Knee, CS; Grande, Tor (Journal article; Peer reviewed, 2014)
      The crystal structures of proton conducting BaZr1-xYxO3-x/2 (BZY05-BZY20) and BaCe0.8Y0.2O2.9 (BCY20) during hydration/dehydration has been studied by in situ high temperature X-ray diffraction and thermal analysis. A ...
    • Composition and morphology tuning during hydrothermal synthesis of SrxBa1−xNb2O6 tetragonal tungsten bronzes studied by in situ X-ray diffraction 

      Grendal, Ola Gjønnes; Blichfeld, Anders Bank; Vu, Tuong-Dan; van Beek, Wouter; Selbach, Sverre Magnus; Grande, Tor; Einarsrud, Mari-Ann (Journal article; Peer reviewed, 2019)
      Current interest in 1D ferroelectric materials calls for cheap, controllable, reproducible and environmentally friendly synthesis routes. Hydrothermal synthesis stands out as one of the most promising routes, but a thorough ...
    • Controlled growth of SrxBa1-xNb2O6 hopper- and cube-shaped nanostructures by hydrothermal synthesis 

      Grendal, Ola Gjønnes; Nylund, Inger-Emma; Blichfeld, Anders Bank; Tominaka, Satoshi; Ohara, Koji; Selbach, Sverre Magnus; Grande, Tor; Einarsrud, Mari-Ann (Journal article; Peer reviewed, 2020)
      Controlling the shape and size of nanostructured materials has been a topic of interest in the field of material science for decades. In this work, the ferroelectric material SrxBa1-xNb2O6 (x = 0.32–0.82, SBN) was prepared ...
    • Controlling Oriented Attachment and in Situ Functionalization of TiO2 Nanoparticles During Hydrothermal Synthesis with APTES 

      Dalod, Antoine Robert Marie; Grendal, Ola Gjønnes; Skjærvø, Susanne Linn; Inzani, Katherine; Selbach, Sverre Magnus; Henriksen, Lars; van Beek, Wouter; Grande, Tor; Einarsrud, Mari-Ann (Journal article; Peer reviewed, 2017)
      Understanding growth mechanisms and the role of surface functionalization is of key importance to control shape and morphology of nanoparticles and their properties. Here, we describe the growth mechanism and the effect ...
    • Coupling and competition between ferroelectricity, magnetism, strain, and oxygen vacancies in AMnO3 perovskites 

      Marthinsen, Astrid; Faber, Carina; Aschauer, Ulrich; Spaldin, Nicola A.; Selbach, Sverre Magnus (Journal article; Peer reviewed, 2016)
      We use first-principles calculations based on density functional theory to investigate the interplay between oxygen vacancies, A-site cation size/tolerance factor, epitaxial strain, ferroelectricity, and magnetism in the ...
    • Crystal Structure Influences Migration along Li and Mg Surfaces 

      Røe, Ingeborg Treu; Selbach, Sverre Magnus; Schnell, Sondre Kvalvåg (Peer reviewed; Journal article, 2020)
      Dendrite formation on Li metal anodes hinders commercialization of more energy-dense rechargeable batteries. Here, we use the migration energy barrier (MEB) for surface transport as a descriptor for dendrite nucleation and ...
    • Defect chemistry and ferroelectric domain walls in hexagonal manganites 

      Småbråten, Didrik René (Doctoral theses at NTNU;2018:263, Doctoral thesis, 2018)
      The hexagonal manganites h-RMnO3 (R=Y, In, Sc, Ho-Lu) have been studied the last two decades for their exotic and diverse functional properties. Their large chemical flexibility makes this material class an ideal chemical ...
    • Defect Chemistry as a Crystal Structure Design Parameter: Intrinsic Point Defects and Ga Substitution in InMnO3 

      Griffin, Sinead M; Reidulff, Mari; Selbach, Sverre Magnus; Spaldin, Nicola A (Journal article, 2017)
      The effect of defect chemistry on the polar and nonpolar phases of hexagonal InMnO3 is investigated using first-principles density functional calculations. Our motivation is to show how point defects and substitutional ...
    • Defect Engineering in Plasmonic Metal Oxide Nanocrystals 

      Runnerstom, Evan J; Bergerud, Amy; Agrawal, Ankit; Johns, Robert W.; Dahlman, Clayton J.; Singh, Ajay; Selbach, Sverre Magnus; Milliron, Delia J. (Journal article; Peer reviewed, 2016)
      Defects may tend to make crystals interesting but they do not always improve performance. In doped metal oxide nanocrystals with localized surface plasmon resonance (LSPR), aliovalent dopants and oxygen vacancies act as ...
    • Development of a mixed-conducting layered oxide for asymmetric oxygen permeable membranes 

      Danmo, Frida Paulsen (Master thesis, 2018)
      Over 100 million tons of pure oxygen gas are produced each year, making it one of the most used chemicals worldwide. As the conventional production process, cryogenic distillation, is very energy demanding, a new, cheaper ...
    • Development of a new class of oxygen ion mixed conductors. 

      Frydenlund, Madelen Mørk (Master thesis, 2014)
      Dense ceramic membranes with mixed ionic and electronic conductivity can separate 100 % pure oxygen from air at elevated temperature. They constitute a much cheaper and more environmentally friendly alternative to cryogenic ...
    • Development of An Asymmetrical Membrane for Oxygen Exchange and Production 

      Kielland, Sigmund Sørensen (Master thesis, 2019)
      Hvert år produseres over 100 millioner tonn ren oksygengass, der mesteparten produseres ved frysedestillering. Denne formen for oksygenproduksjon krever mye tilført energi, og den er derfor ikke godt egnet til å dekke den ...
    • Development of an asymmetrical oxygen permeable membrane based on hexagonal manganites 

      Hoggen, Stine Marie (Master thesis, 2016)
      Pure oxygen is a commodity chemical needed in many industries. Separation of oxygen from air is usually performed by the expensive and highly energy-demanding process of cryogenic distillation. A promising and more ...
    • Development of hexagonal manganites for use in oxygen permeable membranes 

      Nesdal, Silje Kathrin (Master thesis, 2013)
      Mixed ionic-electronic conducting membranes can provide a cheaper and more environmental friendly alternative to cryogenic distillation for production of 100 % pure oxygen. However, most of today's state-of-the-art materials ...