• 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 ...
    • Biocompatibility of (Ba,Ca)(Zr,Ti)O3 piezoelectric ceramics for bone replacement materials 

      Poon, Kara; Wurm, Matthias C.; Evans, Donald; Einarsrud, Mari-Ann; Lutz, Rainer; Glaum, Julia (Journal article; Peer reviewed, 2019)
      Total joint replacement implants are generally designed to physically mimic the biological environment to ensure compatibility with the host tissue. However, implant instability exposes patients to long recovery periods, ...
    • 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 ...
    • Contact-free reversible switching of improper ferroelectric domains by electron and ion irradiation 

      Roede, Erik Dobloug; Mosberg, Aleksander Buseth; Evans, Donald; Bourret, Edith; Yan, Zewu; Van Helvoort, Antonius; Meier, Dennis (Peer reviewed; Journal article, 2021)
      Focused ion beam (FIB) and scanning electron microscopy (SEM) are used to reversibly switch improper ferroelectric domains in the hexagonal manganite ErMnO3. Surface charging is achieved by local ion (positive charging) ...
    • 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, ...
    • Domains and domain walls in multiferroics 

      Evans, Donald; Garcia, Vincent; Meier, Dennis Gerhard; Bibes, Manuel (Journal article, 2020)
      Multiferroics are materials combining several ferroic orders, such as ferroelectricity, ferro- (or antiferro-) magnetism, ferroelasticity and ferrotoroidicity. They are of interest both from a fundamental perspective, as ...
    • Electronic bulk and domain wall properties in B-site doped hexagonal ErMnO3 

      Holstad, Theodor S.; Evans, Donald; Ruff, Alexander; Småbråten, Didrik Rene; Schaab, Jakob; Tzschaschel, Christian; Yan, Zewu; Bourret, Edith; Selbach, Sverre Magnus; Krohns, Stephan; Meier, Dennis (Journal article; Peer reviewed, 2018)
      Acceptor and donor doping is a standard for tailoring semiconductors. More recently, doping was adapted to optimize the behavior at ferroelectric domain walls. In contrast to more than a century of research on semiconductors, ...
    • Ferroelasticity, anelasticity and magnetoelastic relaxation in Co-doped iron pnictide: Ba(Fe0.957Co0.043)2As2 

      Carpenter, Michael A.; Evans, Donald; Schiemer, J. A.; Wolf, Thomas; Adelmann, P.; Böhmer, A. E.; Meingast, C.; Dutton, S. E.; Mukherjee, P.; Howard, Christopher J. (Journal article; Peer reviewed, 2019)
      The hypothesis that strain has a permeating influence on ferroelastic, magnetic and superconducting transitions in 122 iron pnictides has been tested by investigating variations of the elastic and anelastic properties of ...
    • FIB lift-out of conducting ferroelectric domain walls in hexagonal manganites 

      Mosberg, Aleksander Buseth; Roede, Erik Dobloug; Evans, Donald; Holstad, Theodor S.; Bourret, Edith; Yan, Zewu; Van Helvoort, Antonius; Meier, Dennis (Journal article; Peer reviewed, 2019)
      A focused ion beam (FIB) methodology is developed to lift out suitable specimens containing charged domain walls in improper ferroelectric ErMnO3. The FIB procedure allows for extracting domain wall sections with well-defined ...
    • FIB lift-out of conducting ferroelectric domain walls in hexagonal manganites 

      Evans, Donald; Meier, Dennis; Mosberg, Aleksander Buseth; Roede, Erik Dobloug; Holstad, Theodor S.; Bourret, Edith; Yan, Zewu; Van Helvoort, Antonius (Journal article; Peer reviewed, 2019)
      A focused ion beam (FIB) methodology is developed to lift out suitable specimens containing charged domain walls in improper ferroelectric ErMnO3. The FIB procedure allows for extracting domain wall sections with well-defined ...
    • Insulating improper ferroelectric domain walls as robust barrier layer capacitors 

      Puntigam, Lukas; Schultheiss, Jan; Strinic, Ana; Yan, Zewu; Bourret, Edith; Altthaler, Markus; Keszmarki, Istvan; Evans, Donald; Meier, Dennis Gerhard; Krohns, Stephan (Peer reviewed; Journal article, 2021)
      We report the dielectric properties of improper ferroelectric hexagonal (h-)ErMnO3. From the bulk characterization, we observe a temperature and frequency range with two distinct relaxation-like features, leading to high ...
    • Magnetoelastic properties of multiferroic hexagonal ErMnO<inf>3</inf> 

      Fernandez-Posada, C.M.; Haines, C.R.S.; Evans, Donald; Yan, Z.; Bourret, E.; Meier, Dennis; Carpenter, M.A. (Journal article; Peer reviewed, 2022)
    • Observation of Electric-Field-Induced Structural Dislocations in a Ferroelectric Oxide 

      Evans, Donald; Småbråten, Didrik Rene; Holstad, Theodor Secanell; Vullum, Per Erik; Mosberg, Aleksander Buseth; Yan, Zewu; Bourret, Edith; Van Helvoort, Antonius; Selbach, Sverre Magnus; Meier, Dennis (Peer reviewed; Journal article, 2021)
      Dislocations are 1D topological defects with emergent electronic properties. Their low dimensionality and unique properties make them excellent candidates for innovative device concepts, ranging from dislocation-based ...
    • 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 ...
    • Strain relaxation behaviour of vortices in a multiferroic superconductor 

      Evans, Donald; Schiemer, J. A.; Wolf, T.; Adelmann, P.; Böhmer, A. E.; Meingast, C.; Dutton, S. E.; Mukherjee, P.; Hsu, Y.-T.; Carpenter, Michael A. (Journal article; Peer reviewed, 2019)
      The elastic and anelastic properties of a single crystal of Co-doped pnictide Ba(Fe0.957Co0.043)2As2 have been determined by resonant ultrasound spectroscopy in the frequency range 10–500 kHz, both as a function of temperature ...