• 3D aligned-carbon-nanotubes@Li2FeSiO4 arrays as high rate capability cathodes for Li-ion batteries 

      Zhou, Haitao; Lou, Fengliu; Vullum, Per Erik; Einarsrud, Mari-Ann; Chen, De; Vullum-Bruer, Fride (Journal article; Peer reviewed, 2013-09-27)
      3D aligned-carbon-nanotubes (ACNTs)@Li2FeSiO4 nanocomposite arrays on Al foil were developed as cathode materials for Li-ion batteries. The ACNTs were grown directly on an Al foil by a chemical vapor deposition method to ...
    • Atomap - Automated Analysis of Atomic Resolution STEM Images 

      Nord, Magnus Kristofer; Vullum, Per Erik; MacLaren, I; Tybell, Per Thomas Martin; Holmestad, Randi (Journal article, 2017)
      Atomic resolution scanning transmission electron microscopy (STEM) data contain a large amount of information about the structure of a crystalline material. Often, this information is hard to extract, due to the large ...
    • Atomap: a new software tool for the automated analysis of atomic resolution images using two-dimensional Gaussian fitting 

      Nord, Magnus Kristofer; Vullum, Per Erik; MacLaren, Ian; Tybell, Per Thomas Martin; Holmestad, Randi (Journal article; Peer reviewed, 2017)
      Scanning transmission electron microscopy (STEM) data with atomic resolution can contain a large amount of information about the structure of a crystalline material. Often, this information is hard to extract, due to the ...
    • Atomic resolution imaging of beryl: an investigation of the nano-channel occupation 

      Van Helvoort, Antonius; Holst, Bodil; Schmitz, F.D.; Arivazhagan, V.; Vullum, Per Erik (Journal article; Peer reviewed, 2016)
      Beryl in different varieties (emerald, aquamarine, heliodor etc.) displays a wide range of colours that have fascinated humans throughout history. Beryl is a hexagonal cyclo-silicate (ring-silicate) with channels going ...
    • Bandgap measurement of high refractive index materials by off-axis EELS 

      Vatanparast, Maryam; Egoavil, Ricardo; Reenaas, Turid Worren; verbeeck, Johan; Holmestad, Randi; Vullum, Per Erik (Journal article; Peer reviewed, 2017)
      In the present work Cs aberration corrected and monochromated scanning transmission electron microscopy electron energy loss spectroscopy (STEM-EELS) has been used to explore experimental set-ups that allow bandgaps of ...
    • Bottom-Up Fabrication of Oxygen Reduction Electrodes with Atomic Layer Deposition for High-Power-Density PEMFCs 

      Dull, Sam; Xu, Shicheng; Goh, Timothy; Lee, Dong Un; Higgins, Drew; Orazov, Marat; Koshy, David; Vullum, Per Erik; Kirsch, Sebastian; Huebner, Gerold; Torgersen, Jan; Jaramillo, Thomas F; Prinz, Friedrich (Journal article, 2021)
      As the platinum (Pt) loading in proton exchange membrane fuel cell cathodes is driven down to reduce costs, catalyst utilization becomes increasingly important. Here, we report an atomic layer deposition-facilitated electrode ...
    • Broadband infrared and THz transmitting silicon core optical fiber 

      Sørgård, Trygve; Song, Seunghan; Vullum, Per Erik; Kores, Cristine; Mølster, Kjell Martin; Laurell, Fredrik; Hawkins, Thomas A.; Ballato, John; Österberg, Ulf Lennart; Gibson, Ursula (Peer reviewed; Journal article, 2020)
      Silicon waveguide structures are a viable alternative for the transmission of signals over a wide range of frequencies, and new fabrication methods are key to increased applications. In this work, THz transparency of ...
    • Characterization of BaTiO3/La0.7Sr0.3MnO3 Thin Films on SrTiO3(111) Substrates - A Transmission Electron Microscopy Study 

      Holstad, Theodor Secanell (Master thesis, 2016)
      In this work, an oxide thin film system was investigated by using transmission electron microscopy (TEM) techniques. It is of great interest to study such systems due to their current applications as well as potential ...
    • Cold welding of steel and aluminum alloys - Joining processes, intermetallic phases and bond strength 

      Arbo, Siri Marthe (Doctoral theses at NTNU;2020:16, Doctoral thesis, 2020)
      Steel and aluminum are two of the most commonly used metals in today’s society and can be found everywhere, in vehicles, buildings, ships, and in most new electronic devices to name a few. Both metals have desirable ...
    • Compositional and structural properties of pulsed laser-deposited ZnS:Cr films 

      Nematollahi, Mohammadreza; Yang, Xiaodong; Seim, Eivind; Vullum, Per Erik; Holmestad, Randi; Gibson, Ursula; Reenaas, Turid Worren (Journal article; Peer reviewed, 2016)
      We present the properties of Cr-doped zinc sulfide (ZnS:Cr) films deposited on Si(100) by pulsed laser deposition. The films are studied for solar cell applications, and to obtain a high absorption, a high Cr content ...
    • Conductivity control via minimally invasive anti-Frenkel defects in a functional oxide 

      Evans, Donald; Holstad, Theodor Secanell; Mosberg, Aleksander Buseth; Småbråten, Didrik Rene; Vullum, Per Erik; Dadlani, Anup; Shapovalov, Konstantin; Yan, Zewu; Bourret, Edith; Gao, David Zhe; Akola, Jaakko; Torgersen, Jan; Van Helvoort, Antonius; Selbach, Sverre Magnus; Meier, Dennis (Peer reviewed; Journal article, 2020)
      Utilizing quantum effects in complex oxides, such as magnetism, multiferroicity and superconductivity, requires atomic-level control of the material’s structure and composition. In contrast, the continuous conductivity ...
    • Critically testing olivine-hosted putative martian biosignatures in the Yamato 000593 meteorite - Geobiological implications 

      McLoughlin, Nicola; Grosch, Eugene Gerald; Vullum, Per Erik; Guagliardo, Paul; Saunders, Martin; Wacey, David (Journal article; Peer reviewed, 2019)
      On rocky planets such as Earth and Mars the serpentinization of olivine in ultramafic crust produces hydrogen that can act as a potential energy source for life. Direct evidence of fluid–rock interaction on Mars comes from ...
    • Detecting minute amounts of nitrogen in GaNAs thin films using STEM and CBED 

      Vatanparast, Maryam; Shao, Yu-Tsun; Rajpalke, Mohana; Fimland, Bjørn-Ove; Reenaas, Turid Dory; Holmestad, Randi; Vullum, Per Erik; Zuo, Jian Min (Journal article; Peer reviewed, 2021)
      Nitrogen (N) is a common element added to GaAs for band gap engineering and strain compensation. However, detection of small amounts of N is difficult for electron microscopy as well as for other chemical analysis techniques. ...
    • Direct Integration of Strained-Pt Catalysts into Proton-Exchange-Membrane Fuel Cells with Atomic Layer Deposition 

      Xu, Shicheng; Wang, Zhaoxuan; Dull, Sam; Liu, Yunzhi; Lee, Dong Un; Pacheco, Lezama; Orazov, Marat; Vullum, Per Erik; Dadlani, Anup; Vinogradova, Olga; Schindler, Peter; Tam, Qizhan; Schladt, Thomas; Mueller, Jonathan E.; Kirsch, Sebastian; Huebner, Gerold; Higgins, Drew; Torgersen, Jan; Viswanathan, Venkatasubramanian; Jaramillo, Thomas F; Prinz, Friedrich (Peer reviewed; Journal article, 2021)
      The design and fabrication of lattice-strained platinum catalysts achieved by removing a soluble core from a platinum shell synthesized via atomic layer deposition, is reported. The remarkable catalytic performance for the ...
    • Effect of Mn and cooling rates on α-, β- and δ-Al–Fe–Si intermetallic phase formation in a secondary Al–Si alloy 

      Becker, Hanka; Bergh, Tina; Vullum, Per Erik; Leineweber, Andreas; Li, Yanjun (Journal article; Peer reviewed, 2019)
      Secondary Al–Si alloys Al7.1Si(1.5-xMn)Fe(xMn)Mn with xMn = 0, 0.3, 0.375, 0.6, 0.75 at.% have been solidified with different cooling rates: 0.05 K/s, 1.4 K/s, 11.4 K/s and 200 K/s. In the ternary alloy with xMn = 0 at.%, ...
    • Effect of polar (111)-oriented SrTiO3 on initial perovskite growth 

      Hallsteinsen, Ingrid; Nord, Magnus Kristofer; Bolstad, Torstein; Vullum, Per Erik; Boschker, Jos Emiel; Longo, Paulo; Takahashi, Ryota; Holmestad, Randi; Lippmaa, Mikk; Tybell, Per Thomas Martin (Journal article, 2016)
      In crystalline thin film growth a prerequisite is substrate surfaces with a stable and uniform structure and chemical composition. Various substrate treatments were used to obtain atomically smooth, step-and-terrace ...
    • Effects of metal dusting relevant exposures of alloy 601 surfaces on carbon formation and oxide development 

      Guo, Xiaoyang; Vanhaecke, Estelle Marie M.; Vullum, Per Erik; Ma, Jianyu; Panditha Vidana, Daham Sanjaya Gunawardana; Walmsley, John; Chen, De; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2020)
      Ni and Fe are excellent catalysts for carbon formation, and industrial alloys are therefore susceptible to metal dusting corrosion; a costly issue in e.g. synthesis gas manufacture. The objective of this work is to better ...
    • Electron Microscopy Characterization of Aluminium-Copper-Titanium-Steel Joint made using the Hybrid Metal Extrusion & Bonding Method 

      Turgun, Hursanay (Master thesis, 2020)
      Multimaterielle skjøter er nyttige i produksjon av lette strukturer med høy ytelse og funksjonalitet. Denne avhandlingen undersøker en skjøt sammensveiset ved bruk av den innovative Hybrid Metal Extrusion & Bonding (HYB) ...
    • Electron microscopy of intermetallic phases in aluminium-steel joints 

      Bergh, Tina (Doctoral theses at NTNU;2021:168, Doctoral thesis, 2021)
      Joints that combine the light weight of aluminium (Al) alloys with the high strength of steels, can be beneficial in structural components. For instance, in automobiles, Al-steel joints can enable improvement of the ...
    • Epitaxial (100), (110), and (111) BaTiO3 films on SrTiO3 substrates — A transmission electron microscopy study 

      Nylund, Inger-Emma; Ræder, Trygve Magnus; Vullum, Per Erik; Grande, Tor (Peer reviewed; Journal article, 2021)
      Chemical solution deposition (CSD) is a versatile method to fabricate oxide films. Here, the structure and local variations in the chemical composition of BaTiO3 (BTO) films prepared by CSD on (100), (110), and (111) SrTiO3 ...