Blar i Institutt for fysikk på tidsskrift "Ultramicroscopy"

Viser treff 1-8 av 8

    • Analytical transmission cross-coefficients for pink beam X-ray microscopy based on compound refractive lenses 

      Falch, Ken Vidar; Detlefs, Carsten; Snigirev, Anatoly; Mathiesen, Ragnvald (Journal article; Peer reviewed, 2018)
      Analytical expressions for the transmission cross-coefficients for x-ray microscopes based on compound refractive lenses are derived based on Gaussian approximations of the source shape and energy spectrum. The effects of ...

    • AutomAl 6000: Semi-automatic structural labelling of HAADF-STEM images of precipitates in Al–Mg–Si(–Cu) alloys 

      Tvedt, Haakon; Marioara, Calin Daniel; Thronsen, Elisabeth; Hell, Christoph Martin; Andersen, Sigmund Jarle; Holmestad, Randi (Journal article; Peer reviewed, 2022)
      When the Al–Mg–Si(–Cu) alloy system is subjected to age hardening, different types of precipitates nucleate depending on the composition and thermomechanical treatment. The main hardening precipitates extend as needles, ...

    • Bandgap measurement of high refractive index materials by off-axis EELS 

      Vatanparast, Maryam (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 ...

    • 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 ...

    • 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. ...

    • Optimising multi-frame ADF-STEM for high-precision atomic-resolution strain mapping 

      Jones, Lewys; Wenner, Sigurd; Nord, Magnus Kristofer; Ninive, Per Harald; Løvvik, Ole Martin; Holmestad, Randi; Nellist, P.D. (Journal article; Peer reviewed, 2017)
      Annular dark-field scanning transmission electron microscopy is a powerful tool to study crystal defects at the atomic scale but historically single slow-scanned frames have been plagued by low-frequency scanning-distortions ...

    • Scanning precession electron diffraction data analysis approaches for phase mapping of precipitates in aluminium alloys 

      Thronsen, Elisabeth; Bergh, Tina; Thorsen, Tor Inge; Christiansen, Emil; Frafjord, Jonas; Crout, Philip; Van Helvoort, Antonius Theodorus Johannes; Midgley, Paul A.; Holmestad, Randi (Peer reviewed; Journal article, 2023)
      Mapping the spatial distribution of crystal phases with nm-scale spatial resolution is an important characterisation task in studies of multi-phase materials. One popular approach is to use scanning precession electron ...

    • Zernike phase contrast in high-energy x-ray transmission microscopy based on refractive optics 

      Falch, Ken Vidar; Lyubormiskiy, Mikhail; Casari, Daniele; Snigirev, Anatoly; Snigireva, Irina; Detlefs, Carsten; Di Michiel, Marco; Lyatun, Ivan; Mathiesen, Ragnvald (Journal article; Peer reviewed, 2018)
      The current work represents the first implementation of Zernike phase contrast for compound refractive lens based x-ray microscopy, and also the first successful Zernike phase contrast experiment at photon energies above ...