2020/06/06 by Min-Han Lee, Min‐Han Lee, Yoav Kalcheim +3 · 43 citations
Engineering · Materials Science · Physics and Astronomy · #Advanced Memory and Neural Computing #Electronic and Structural Properties of Oxides #Inorganic chemistry #Materials science #Metal #Metallurgy #Metal–insulator transition #Nanotechnology #Oxide #Oxygen #Physical chemistry #Stoichiometry #Thin film #Transition Metal Oxide Nanomaterials #Vanadium #Vanadium oxide #cond-mat.mtrl-sci
paper · pdf · doi:10.1021/acsami.0c18327
published in ACS Applied Materials & Interfaces 13(1), 887-896 (American Chemical Society)
arxiv created 2020/06/06 · arxiv updated 2020/12/21 · openalex publication_date 2020/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Vanadium oxides are strongly correlated materials which display metal–insulator transitions (MITs) as well as various structural and magnetic properties that depend heavily on oxygen stoichiometry. Therefore, it is crucial to precisely control oxygen stoichiometry in these materials, especially in thin films. This work demonstrates a high-vacuum gas evolution technique which allows for the modification of oxygen concentrations in VO X thin films by carefully tuning the thermodynamic conditions. We were able to control the evolution between VO 2, V 3 O 5, and V 2 O 3 phases on sapphire substrates, overcoming the narrow phase stability of adjacent Magnéli phases. A variety of annealing routes were found to achieve the desired phases and eventually control the MIT. The pronounced MIT of the transformed films along with the detailed structural investigations based on X-ray diffraction measurements and X-ray photoelectron spectroscopy show that optimal stoichiometry is obtained and stabilized. Using this technique, we find that the thin-film V–O phase diagram differs from that of the bulk material because of strain and finite size effects. Our study demonstrates new pathways to strategically tune the oxygen stoichiometry in complex oxides and provides a road map for understanding the phase stability of VO X thin films.