抄録
Understanding the mechanism of the insulator-metal transition (IMT) in VO2 is a necessary step in optimising this material's properties for a range of functional applications. Here, Rietveld refinement of synchrotron X-ray powder diffraction patterns is performed on thermochromic V1-xWxO2 (0.0 ≤ x ≤ 0.02) nanorod aggregates over the temperature range 100 ≤ T ≤ 400 K to examine the effect of doping on the structure and properties of the insulating monoclinic (M1) phase and metallic rutile (R) phase. Precise measurement of the lattice constants of the M1 and R phases enabled the onset (Ton) and endset (Tend) temperatures of the IMT to be determined accurately for different dopant levels. First-principles calculations reveal that the observed decrease in both Ton and Tend with increasing W content is a result of Peierls type V-O-V dimers being replaced by linear W-O-V dimers with a narrowing of the band gap. The results are interpreted in terms of the bandwidth-controlled Mott-Hubbard IMT model, providing a more detailed understanding of the underlying physical mechanisms driving the IMT as well as a guide to optimising properties of VO2-based materials for specific applications.
本文言語 | English |
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ページ(範囲) | 7984-7994 |
ページ数 | 11 |
ジャーナル | Physical Chemistry Chemical Physics |
巻 | 22 |
号 | 15 |
DOI | |
出版ステータス | Published - 2020 4月 21 |
外部発表 | はい |
ASJC Scopus subject areas
- 物理学および天文学(全般)
- 物理化学および理論化学