Background and activities

PhD candidate in the FACET group since August of 2019, working in the sub group Functional Topological Systems.

Main supervisor: Professor Dennis Gerhard Meier

Co-supervisor: Professor Antonius T. J. van Helvoort

Research

My research focuses on studying the defect chemistry of complex oxides with atom probe tomography (APT). The primary focus has been towards bulk ferroelectric systems where I have looked into low concentration doping and local chemical fluctuations in connection to the microsctructure. In addition, I am also investigating thin films where we aim to resolve 3D structures and interfaces through their chemical signature. By applying APT we are able to resolve point defects at the atomic scale and bring new experimental insight into the defect chemistry of materials heavily investigated for their potential to be used in oxide electronics.

Background

Before my PhD position, I did my master's thesis at the TEM Gemini Centre here at NTNU, under the supervision of Professor Antonius T. J. van Helvoort, focusing on visualizing the domain structures of ferroelectric complex oxides by transmission electron microscopy. The thesis was completed in June of 2019.

Scientific, academic and artistic work

Displaying a selection of activities. See all publications in the database

Journal publications

Report/dissertation

  • Hunnestad, Kasper Aas; Van Helvoort, Antonius. (2019) Visualizing Ferroelectric Domain Structures in ErMnO3 and Pb5Ge3O11 by Electron Microscopy. 2019.

Others

  • Hunnestad, Kasper Aas; Das, Hena; Hatzoglou, Constantinos; Holtz, Megan, E.; Brooks, Charles M.; Van Helvoort, Antonius; Schlom, Darrel G.; Mundy, Julia; Meier, Dennis. (2022) Quantifying charged defects in multiferroic superlattices using atom probe tomography. QUOROM-6 ; 2022-03-31 - 2022-03-31.
  • Hunnestad, Kasper Aas; Hatzoglou, Constantinoss; Khalid, Muhammad Zeeshan; Vullum, Per Erik; Yan, Zewu; Bourret, Edith; Van Helvoort, Antonius; Meier, Dennis. (2021) Detection of Individual Dopants in a Semiconducting Functional Oxide. Atom probe tomography & microcsopy ; 2021-09-28.
  • Hunnestad, Kasper Aas; Hatzoglou, Constantinoss; Khalid, Muhammad Zeeshan; Vullum, Per Erik; Zewu, Yan; Bourret, Edith; Selbach, Sverre Magnus; Van Helvoort, Antonius; Meier, Dennis. (2021) 3D analysis of dopants in a multiferroic oxide by atom probe tomography. Norwegian Nanosymposium ; 2021-10-05.
  • Hunnestad, Kasper Aas; Hatzoglou, Constantinoss; Van Helvoort, Antonius; Meier, Dennis. (2021) Atomic-scale analysis of individual dopants in a functional oxide. German Physical Association ; 2021-09-28.
  • Hunnestad, Kasper Aas; Schultheiß, Jan; Holstad, Theodor S.; Van Helvoort, Antonius; Meier, Dennis. (2019) Nanoscale chemical mapping in 3D by atom probe tomography: Needle preparation. Norwegian Nanosymposium . Nano@NTNU; Trondheim. 2019-10-16 - 2019-10-18.