2023/06/30 by Kasper A. Hunnestad, Hunnestad, K. A., Hena Das +17
Engineering · Environmental Science · Materials Science · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Magnetic Field Sensors Techniques #Materials Science (cond-mat.mtrl-sci) #Minerals Flotation and Separation Techniques
paper · pdf · doi:10.48550/arxiv.2307.00139
openalex publication_date 2023/06/30 · openalex created_date 2023/07/05 · openalex updated_date 2026/08/01
Oxide heterostructures exhibit a vast variety of unique physical properties. Examples are unconventional superconductivity in layered nickelates and topological polar order in (PbTiO3)n/(SrTiO3)n superlattices. Although it is clear that variations in oxygen content are crucial for the electronic correlation phenomena in oxides, it remains a major challenge to quantify their impact. Here, we measure the chemical composition in multiferroic (LuFeO3)9/(LuFe2O4)1 superlattices, revealing a one-to-one correlation between the distribution of oxygen vacancies and the electric and magnetic properties. Using atom probe tomography, we observe oxygen vacancies arranging in a layered three-dimensional structure with a local density on the order of 1014 cm-2, congruent with the formula-unit-thick ferrimagnetic LuFe2O4 layers. The vacancy order is promoted by the locally reduced formation energy and plays a key role in stabilizing the ferroelectric domains and ferrimagnetism in the LuFeO3 and LuFe2O4 layers, respectively. The results demonstrate the importance of oxygen vacancies for the room-temperature multiferroicity in this system and establish an approach for quantifying the oxygen defects with atomic-scale precision in 3D, giving new opportunities for deterministic defect-enabled property control in oxide heterostructures.