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Updated: Dec 23, 2025
Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
Composition, crystallography, and oxygen vacancy ordering impacts on the oxygen ion conductivity of lanthanum
Tridip Das1, Jason D Nicholas, Yue Qi
1Chemical Engineering & Materials Science Department, Michigan State University, 428 South Shaw Lane, 2527 Engineering Building, East Lansing, MI 48824, USA. yueqi@egr.msu.edu.
Abstract:
This work presents a comprehensive computational study showing how aliovalent doping, crystal structure, and oxygen vacancy interactions impact the oxygen vacancy conductivity of lanthanum strontium ferrite (LSF) as a function of temperature in air. First, density functional theory (DFT) calculations were performed to obtain the oxygen vacancy migration barriers and understand the oxidation state changes on neighboring Fe atoms during oxygen vacancy migration. The oxygen migration barrier energy and the corresponding diffusion coefficient were then combined with previously determined mobile oxygen vacancy concentrations to predict the overall oxygen vacancy conductivity and compare it with experimentally measured values. More importantly, the impact of phase changes, the La/Sr ratio, and the oxygen non-stoichiometry on the mobile oxygen vacancy concentration, diffusivity, and conductivity were analyzed. It was found that stabilizing rhombohedral LSF or cubic SFO (through doping or other means), such that oxygen-vacancy-ordering-induced phase transitions are prevented, leads to high oxygen conductivity under solid oxide fuel cell operating conditions.
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