Analyzing Buried Defects in Vanadium Oxide with Bragg Coherent Diffractive Imaging

Metal-insulator transitions accompanied by structural phase transitions in vanadium oxides have attracted considerable scientific interest for applications in photonics, sensing, and IR light modulation. Many stoichiometries have been explored, including V₂O₃, VO₂, V₂O₅, and V₃O₅¹. While the precise mechanism of the transition is controversial, it is influenced by a number of properties like crystal strain, morphology, and electron correlations². Therefore, further study of nanoscale strain and crystal defects in these crystals is pivotal to advance understanding of these transitions.

Past studies of defects in vanadium oxides have been limited to surface techniques or destructive characterization. These fail to give volumetric information, masking the presence of buried defects in as-grown crystals. In this work we use Bragg Coherent Diffractive Imaging (BCDI) to analyze in 3 dimensions a V₂O₃ particle with nanoscale resolution and picometer strain sensitivity. We identify buried defects in the crystal and analyze the role these defects play in particle morphology. Our results emphasize the role defects play in the growth of 2D flake-like V₂O₃ particles.

¹ C. Piccirillo et al, Chemical Vapor Deposition 13, 145 (2007)

² A. D’Elia et al, Applied Surface Science 540, 148341 (2021)