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• Bondevik, Tarjei; Ness, Heine Håland; Bazioti, Kalliopi; Norby, Truls Eivind; Løvvik, Ole Martin & Koch, Christoph T. [Vis alle 7 forfattere av denne artikkelen] (2019). Investigation of the electrostatic potential of a grain boundary in Y-substituted BaZrO3 using inline electron holography. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 21(32), s. 17662–17672. doi: 10.1039/c9cp02676b. Fulltekst i vitenarkiv Vis sammendrag

  We apply inline electron holography to investigate the electrostatic potential across an individual BaZr0.9Y0.1O3 grain boundary. With holography, we measure a grain boundary potential of −1.3 V. Electron energy loss spectroscopy analyses indicate that barium vacancies at the grain boundary are the main contributors to the potential well in this sample. Furthermore, geometric phase analysis and density functional theory calculations suggest that reduced atomic density at the grain boundary also contributes to the experimentally measured potential well.

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• Ness, Heine Håland; Bondevik, Tarjei & Prytz, Øystein (2018). Basic principle of electron holography.
• Ness, Heine Håland; Prytz, Øystein & Bondevik, Tarjei (2018). Inline Electron Holography - Theoretical and experimental aspects. Unipub forlag. Vis sammendrag

  With ever decreasing size of electronics the need study of sub micrometer structures is prominent. The transmission electron microscope (TEM) gives the possibility to study structures at the nano scale. One technique that the TEM enables is inline electron holography, whith this technique, the electrostatic potential of a material can be found. By using a defocus series of electron micrographs, the full electron wavefunction may be recovered by simulating the processes that take place in the TEM. The phase of the electron wavefunction holds information of the potential experienced by the electron wave. In this thesis, we study a state of the art inline electron holography technique, titled Full Resolution Wave Reconstruction (FRWR). A review of the reconstruction algorithm is given, and we have tested the FRWR capabilities to recover the mean inner potential of Cu2O, and the potential profile across a Cu2O/CuO/ZnO heterojunction. In addition the effects of experimental setup such as objective aperture and energy filtering have been investigated. Furthermore, theoretical values of the mean inner potential have been calculated from following two different models, a non-binding atom model and an ionized atom model. The theoretical values for the mean inner potential of Cu2O was found to be 17.29 V for a nonbinding model and 12.78 V for an ionized atom model, whereas the experiential values was estimated to be 15.46 ± 2.18 V. For the Cu2O/CuO interface, the theoretical calculations gave a potential of 3.13 V and 2.34 V for the non-binding and ionic models, respectively. The experimental value was 1.33 ± 0.70 V. The CuO/ZnO transition gave theoretical values of 3.14 V for the non-binding model and 2.34 V for the ionic model, and an experimental value of 2.60 ± 0.84 V.

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