Abstract
Point defects govern macroscopic electromagnetic properties in complex oxide such as multiferroic h-LuFeO3. Detecting these defects through HAADF-STEM requires precise structural quantification of the image data. In this thesis, we present a comprehensive investigation of antisite point defect detection in h-LuFeO3, from designing an image analysis workflow to the analytical detection of antisites. We first demonstrate a HAADF image analysis workflow to identify and quantify atomic sites in h-LuFeO3, resolving local signal-to-noise ratio variations and structural complexities caused by ferroelectric atomic displacements. Through this workflow, a comparison of experiments against metrics from frozen-phonon multislice simulations confirms the presence of LueFe and FeLu antisites validated by EELS. We evaluate defect concentrations through comparisons with stoichiometry and thermodynamics and further confirm the detection of LuFe through local lattice relaxation. While precise detection of both LuFe and FeLu antisites remains a challenge for future work, this thesis establishes a framework for the rigorous confirmation and analysis of antisites in h-LuFeO3.
Committee Chair
Rohan Mishra
Committee Members
Sang-Hoon Bae, Francisco Lagunas Vargas
Degree
Master of Science (MS)
Author's Department
Mechanical Engineering & Materials Science
Document Type
Thesis
Date of Award
Spring 5-2026
Language
English (en)
Author's ORCID
https://orcid.org/0009-0000-2304-4039
Recommended Citation
Wu, Jianan, "Quantitative HAADF-STEM Enabled Detection of Antisites in Multiferroic h-LuFeO3" (2026). McKelvey School of Engineering Theses & Dissertations. 1354.
https://openscholarship.wustl.edu/eng_etds/1354