Kasper Aas Hunnestad

About

Starting in 2023, Kasper Aas Hunnestad works as a postdoctoral fellow in the GAMES project, affiliated with the Center for Geophysical Forecasting.

Biography

Hunnestad obtained a Master's degree in 2019 in Applied Physics at the TEM Gemini Centre, Department of Physics, NTNU, under the supervision of Professor Antonius T. J. van Helvoort.

Following the Master's Degree, Hunnestad began a PhD position in the FACET group, Department of Materials Science, NTNU. The position was supervised by Professor Dennis Gerhard Meier, and completed in 2023.

Research

Current research

For his postdoctoral research, Hunnestad works on ultrasound measurements of CO₂ gas. A custom CO₂ tank laboratory is under construction at NTNU, instrumented with an array of ultrasonic transducers and flow-controlled gas injection capability to investigate the migration of gas in geological structures. The laboratory tank is a 1:2000 scaled environment which will be fitted with scaled models of real fields.

Previous research

His research during his PhD focused on studying the defect chemistry of complex oxides by applying an advanced microscopy technique called atom probe tomography (APT). Primarily, bulk ferroelectric systems have been my main interest, where I looked into low-concentration doping and local chemical fluctuations in connection to the microstructure. In addition, thin films and layered structures were investigated where the aim was to resolve 3D structures and interfaces through their chemical signature. By applying APT I was 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.

Publications

Atomic-scale 3D imaging of individual dopant atoms in an oxide semiconductor

Research article in Nature Communication.

2025

Richarz, Leonie; Skogvoll, Ida Cathrine; Tokle, Egil Ytterli; Hunnestad, Kasper Aas; Ludacka, Ursula; He, Jiali. (2025) Ferroelectric Domain Walls for Environmental Sensors. ACS Applied Materials & Interfaces
Academic article

2024

Conroy, Michele; Småbråten, Didrik Rene; Ophus, Colin; Shapovalov, Konstantin; Ramasse, Quentin M.; Hunnestad, Kasper Aas. (2024) Observation of Antiferroelectric Domain Walls in a Uniaxial Hyperferroelectric. Advanced Materials
Academic article
Hunnestad, Kasper Aas; Das, Hena; hatzoglou, constantinos; Holtz, Megan E.; Brooks, Charles M.; Van Helvoort, Antonius. (2024) 3D oxygen vacancy distribution and defect-property relations in an oxide heterostructure. Nature Communications
Academic article
Ludacka, Ursula; He, Jiali; Qin, Shuyu; Zahn, Manuel Peter; Christiansen, Emil; Hunnestad, Kasper Aas. (2024) Imaging and structure analysis of ferroelectric domains, domain walls, and vortices by scanning electron diffraction. npj Computational Materials
Academic article
Wolk, Katharina; Dragland, Ruben Skjelstad; Chavez Panduro, Elvia Anabela; Hjelmstad, Michael E.; Richarz, Leonie; Yan, Zewu. (2024) Coexistence of multi-scale domains in ferroelectric polycrystals with non-uniform grain-size distributions. Matter
Academic article

2023

Nordahl, Gregory; Jones, Lewys; Christiansen, Emil; Hunnestad, Kasper Aas; Nord, Magnus. (2023) Correcting for probe wandering by precession path segmentation. Ultramicroscopy
Academic article
Hunnestad, Kasper Aas; Hatzoglou, hatzoglou; Vurpillot, F.; Nylund, Inger-Emma; Yan, Z.; Bourret, E.. (2023) Correlating laser energy with compositional and atomic-level information of oxides in atom probe tomography. Materials Characterization
Academic article
Hatzoglou, Constantinos; Da Costa, Gérald; Wells, Peter; Ren, Xiaochen; Geiser, Brian P; Larson, David J. (2023) Introducing a Dynamic Reconstruction Methodology for Multilayered Structures in Atom Probe Tomography. Microscopy and Microanalysis
Academic article
Hunnestad, Kasper Aas; Das, Hena; Hatzoglou, hatzoglou; Holtz, Megan E.; Brooks, Charles M.; Van Helvoort, Antonius. (2023) 3D oxygen vacancy order and defect-property relations in multiferroic (LuFeO3)9/(LuFe2O4)1 superlattices. arXiv.org
Academic article
Hunnestad, Kasper Aas; Schultheiss, Jan Erich; Mathisen, Anders Christian; Ushakov, Ivan; Hatzoglou, Constantinos; Van Helvoort, Antonius. (2023) Quantitative Mapping of Chemical Defects at Charged Grain Boundaries in a Ferroelectric Oxide. Advanced Materials
Academic article

2022

Gradauskaite, Elzbieta; Hunnestad, Kasper Aas; Meier, Quintin; Meier, Dennis; Trassin, Morgan. (2022) Ferroelectric Domain Engineering Using Structural Defect Ordering. Chemistry of Materials
Academic article
Hunnestad, Kasper Aas; Hatzoglou, Constantinos; Khalid, Muhammad Zeeshan; Vullum, Per Erik; Yan, Zewu; Bourret, Edith. (2022) Atomic-scale 3D imaging of individual dopant atoms in an oxide semiconductor. Nature Communications
Academic article

2020

Bak, Ohheum; Holstad, Theodor Secanell; Tan, Yueze; Lu, Haidong; Evans, Donald; Hunnestad, Kasper Aas. (2020) Observation of Unconventional Dynamics of Domain Walls in Uniaxial Ferroelectric Lead Germanate. Advanced Functional Materials
Academic article
Hunnestad, Kasper Aas; Roede, Erik Dobloug; Helvoort, Antonius T. J. van; Meier, Dennis Gerhard. (2020) Characterization of ferroelectric domain walls by scanning electron microscopy. Journal of Applied Physics
Academic literature review

2019

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

Journal publications

Richarz, Leonie; Skogvoll, Ida Cathrine; Tokle, Egil Ytterli; Hunnestad, Kasper Aas; Ludacka, Ursula; He, Jiali. (2025) Ferroelectric Domain Walls for Environmental Sensors. ACS Applied Materials & Interfaces
Academic article
Conroy, Michele; Småbråten, Didrik Rene; Ophus, Colin; Shapovalov, Konstantin; Ramasse, Quentin M.; Hunnestad, Kasper Aas. (2024) Observation of Antiferroelectric Domain Walls in a Uniaxial Hyperferroelectric. Advanced Materials
Academic article
Hunnestad, Kasper Aas; Das, Hena; hatzoglou, constantinos; Holtz, Megan E.; Brooks, Charles M.; Van Helvoort, Antonius. (2024) 3D oxygen vacancy distribution and defect-property relations in an oxide heterostructure. Nature Communications
Academic article
Ludacka, Ursula; He, Jiali; Qin, Shuyu; Zahn, Manuel Peter; Christiansen, Emil; Hunnestad, Kasper Aas. (2024) Imaging and structure analysis of ferroelectric domains, domain walls, and vortices by scanning electron diffraction. npj Computational Materials
Academic article
Wolk, Katharina; Dragland, Ruben Skjelstad; Chavez Panduro, Elvia Anabela; Hjelmstad, Michael E.; Richarz, Leonie; Yan, Zewu. (2024) Coexistence of multi-scale domains in ferroelectric polycrystals with non-uniform grain-size distributions. Matter
Academic article
Nordahl, Gregory; Jones, Lewys; Christiansen, Emil; Hunnestad, Kasper Aas; Nord, Magnus. (2023) Correcting for probe wandering by precession path segmentation. Ultramicroscopy
Academic article
Hunnestad, Kasper Aas; Hatzoglou, hatzoglou; Vurpillot, F.; Nylund, Inger-Emma; Yan, Z.; Bourret, E.. (2023) Correlating laser energy with compositional and atomic-level information of oxides in atom probe tomography. Materials Characterization
Academic article
Hatzoglou, Constantinos; Da Costa, Gérald; Wells, Peter; Ren, Xiaochen; Geiser, Brian P; Larson, David J. (2023) Introducing a Dynamic Reconstruction Methodology for Multilayered Structures in Atom Probe Tomography. Microscopy and Microanalysis
Academic article
Hunnestad, Kasper Aas; Das, Hena; Hatzoglou, hatzoglou; Holtz, Megan E.; Brooks, Charles M.; Van Helvoort, Antonius. (2023) 3D oxygen vacancy order and defect-property relations in multiferroic (LuFeO3)9/(LuFe2O4)1 superlattices. arXiv.org
Academic article
Hunnestad, Kasper Aas; Schultheiss, Jan Erich; Mathisen, Anders Christian; Ushakov, Ivan; Hatzoglou, Constantinos; Van Helvoort, Antonius. (2023) Quantitative Mapping of Chemical Defects at Charged Grain Boundaries in a Ferroelectric Oxide. Advanced Materials
Academic article
Gradauskaite, Elzbieta; Hunnestad, Kasper Aas; Meier, Quintin; Meier, Dennis; Trassin, Morgan. (2022) Ferroelectric Domain Engineering Using Structural Defect Ordering. Chemistry of Materials
Academic article
Hunnestad, Kasper Aas; Hatzoglou, Constantinos; Khalid, Muhammad Zeeshan; Vullum, Per Erik; Yan, Zewu; Bourret, Edith. (2022) Atomic-scale 3D imaging of individual dopant atoms in an oxide semiconductor. Nature Communications
Academic article
Bak, Ohheum; Holstad, Theodor Secanell; Tan, Yueze; Lu, Haidong; Evans, Donald; Hunnestad, Kasper Aas. (2020) Observation of Unconventional Dynamics of Domain Walls in Uniaxial Ferroelectric Lead Germanate. Advanced Functional Materials
Academic article
Hunnestad, Kasper Aas; Roede, Erik Dobloug; Helvoort, Antonius T. J. van; Meier, Dennis Gerhard. (2020) Characterization of ferroelectric domain walls by scanning electron microscopy. Journal of Applied Physics
Academic literature review

Report

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

Outreach

3D-modeller på atomnivå lærer oss hvorfor dingser fungerer

Short promotion article for non-specialists.