Nanoscale Chemical Analysis of Ferroic Materials and Phenomena
Doctoral thesis
Permanent lenke
https://hdl.handle.net/11250/3114058Utgivelsesdato
2023Metadata
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Sammendrag
The discovery of new physical phenomena in materials is closely linked to the progress in characterization and is propelled by the ability to observe and study physical processes occurring at the atomic level. Newly incorporated into the toolkit of nanoscale research is Atom Probe Tomography (APT), a technique that provides insight into the chemical composition with sub-nanometer spatial resolution. In this thesis, APT is applied to study ferroelectric oxide materials, an important material class for future electronic devices, with the aim of demonstrating its feasibility and power to unravel correlations between the local chemical composition and emergent functional properties.
The thesis is divided into three parts, beginning with an analysis of the concentration, distribution, and site-preference of solute dopants in complex oxides. The second part discusses the segregation of point defects towards naturally occurring interfaces in ferroelectrics compounds, namely the grain boundaries and domain walls. The defect segregation is further linked to the emergent electronic properties. In the last part, thin films and superlattice systems are investigated, where the defect distribution is shown to directly correlate to the stability of the ferroelectric domain walls.
The work presented in this thesis demonstrates the outstanding potential and general feasibility of applying APT to study composition-property relations in ferroelectric oxide systems. Correlations between defect chemistry and ferroic phenomena can be experimentally probed with nanoscale spatial resolution, opening an avenue to obtain a deeper understanding of ferroic materials.