• Anisotropic in-plane dielectric and ferroelectric properties of tensile-strained BaTiO3 films with three different crystallographic orientations 

      Ræder, Trygve Magnus; Holstad, Theodor Secanell; Nylund, Inger-Emma; Glaum, Julia; Einarsrud, Mari-Ann; Meier, Dennis; Grande, Tor (Peer reviewed; Journal article, 2021)
      Ferroelectric properties of films can be tailored by strain engineering, but a wider space for property engineering can be opened by including crystal anisotropy. Here, we demonstrate a huge anisotropy in the dielectric ...
    • Application of a long short-term memory for deconvoluting conductance contributions at charged ferroelectric domain walls 

      Holstad, Theodor Secanell; Ræder, Trygve Magnus; Evans, Donald; Småbråten, Didrik Rene; Krohns, Stephan; Schaab, Jakob; Yan, Zewu; Bourret, Edith; Helvoort, Antonius T. J. van; Grande, Tor; Selbach, Sverre Magnus; Agar, Joshua; Meier, Dennis Gerhard (Peer reviewed; Journal article, 2020)
      Ferroelectric domain walls are promising quasi-2D structures that can be leveraged for miniaturization of electronics components and new mechanisms to control electronic signals at the nanoscale. Despite the significant ...
    • 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 ...
    • 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 ...
    • Domain wall mobility and roughening in doped ferroelectric hexagonal manganites 

      Småbråten, Didrik Rene; Holstad, Theodor Secanell; Evans, Donald; Zewu, Yan; Bourret, Edith; Meier, Dennis; Selbach, Sverre Magnus (Peer reviewed; Journal article, 2020)
      The macroscopic performance of ferroelectric and piezoelectric devices depends strongly on domain wall dynamics. It is clear that structural defects, such as vacancies, interstitials, and dopants codetermine the dynamics, ...
    • Emergent nanoscale functionality in uniaxial ferroelectrics 

      Holstad, Theodor Secanell (Doctoral theses at NTNU;2020:138, Doctoral thesis, 2020)
      This thesis has been focused on the characterization and manipulation of the electronic nanoscale properties of domains and domain walls in uniaxial ferroelectrics. Two classes of uniaxial ferroelectrics have been investigated, ...
    • Observation of Unconventional Dynamics of Domain Walls in Uniaxial Ferroelectric Lead Germanate 

      Bak, Ohheum; Holstad, Theodor Secanell; Lu, Haidong; Evans, Donald; Hunnestad, Kasper Aas; Wang, Bo; Becker, Petra; Bohatý, Ladislav; Helvoort, Antonius T. J. van; Gregg, J Marty; Meier, Dennis Gerhard; Gruverman, Alexei (Peer reviewed; Journal article, 2020)
      Application of scanning probe microscopy techniques such as piezoresponse force microscopy (PFM) opens the possibility to re‐visit the ferroelectrics previously studied by the macroscopic electrical testing methods and ...