The role of defects on the metal-insulator transition in V2O3 and VO2
ORAL
Abstract
V2O3 and VO2, are prototypical strongly-correlated materials that undergo a metal-insulator transition (MIT). The MIT in both materials leads to a concomitant structural phase transition and a magnetic phase transition in V2O3. Recent experiments [PRB 91, 205123, 2015] explored the sensitivity of the MIT to defects and demonstrated the MIT phenomenon in V2O3 is sensitive to the presence of defects while it is robust in VO2. To explore the underlying mechanisms for this behavior we performed first-principles calculations to assess the role of defects on the structural, magnetic and electronic properties of V2O3 and VO2. In V2O3 we find defects disrupt the antiferromagnetic (AFM) order in the insulating phase. We also find small polarons form through self-trapping or due to defects. We assess the impact of this phenomenon on the spin-flip energy between the metallic paramagnetic and the insulating AFM state with the goal of understanding how this impacts the MIT temperature. In VO2, we explore the impact of defects on the vanadium dimerization in the insulating phase and the impact on the MIT.
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Presenters
Darshana Wickramaratne
NRC Research Associate residing at, US Naval Research Laboratory, Washington, DC 20375, USA, Naval Research Laboratory, Materials Department, University of California, Santa Barbara, University of California, Santa Barbara
Authors
Darshana Wickramaratne
NRC Research Associate residing at, US Naval Research Laboratory, Washington, DC 20375, USA, Naval Research Laboratory, Materials Department, University of California, Santa Barbara, University of California, Santa Barbara
Noam Bernstein
Center for Computational Materials Science, US Naval Research Laboratory, Washington, DC 20375, USA, United States Naval Research Laboratory, Naval Research Laboratory
Igor Mazin
Center for Computational Materials Science, US Naval Research Laboratory, Washington, DC 20375, USA, United States Naval Research Laboratory
