Mr. Gil Levi - M.Sc. Candidate
06/09/2026
David Wang Auditorium, 3rd Floor, Dalia Maydan Bldg.
13:30
Vanadium sesquioxide (V₂O₃) undergoes a first-order metal–insulator transition accompanied by pronounced structural, electronic, and optical changes. These properties make it both a model system for correlated-electron physics and a promising platform for resistive-switching-based neuromorphic applications. Like many correlated materials, however, V₂O₃ is highly sensitive to variations in strain and stoichiometry. Although this sensitivity can complicate device behavior, it also provides opportunities for tuning functionality. This work demonstrates how microstructural heterogeneity and controlled electroforming can be harnessed for this purpose.
The first part of the work examines the role of microstructural defects in determining the spatial distribution of metallic and insulating phases. Using a combination of electrical transport measurements, X-ray diffraction, high-resolution scanning transmission electron microscopy, and cryogenic optical microscopy, we imaged the metal–insulator transition in strained V₂O₃ thin films. The results reveal that nanoscale twinning produces substantial spatial variations in the local transition temperature, leading to corresponding changes in the electrical properties of V₂O₃ devices.
The second part investigates nonvolatile memory effects induced by resistive switching. Within the hysteretic regime of V₂O₃, switching redistributes metallic and insulating domains, producing a memory effect that is erased by thermal cycling. At lower temperatures, switching generates a persistent, defect-mediated reduction in switching voltage and power that survives thermal cycling. Integrated current-limiting resistors suppress destructive current surges, enabling post-fabrication tuning of the switching voltage and power.
Together, these results highlight the importance of characterizing and controlling nanoscale heterogeneity for understanding and engineering resistive-switching functionality in strongly correlated materials.