Abstract
The structural aspects of the insulator–metal transition (IMT) characteristics of VO2 are sensitive to the octahedral symmetry variation of VO6. By varying substrate orientation (c-, a-, and m-plane Al2O3), the correlation between IMT temperature and local symmetry is investigated. For a VO2 film deposited on m-plane Al2O3, which has high symmetry due to fewer domain boundaries induced by m-plane Al2O3, the IMT temperature is low (326.47 K). In contrast, for a film deposited on c-plane Al2O3 (having lower symmetry), the IMT temperature is the highest (336.74 K) among the films used in this work. Furthermore, temperature-dependent Raman spectra reveals that the structural phase transition temperature decreases in the order of the VO2 film deposited on c-, a-, and m-plane Al2O3, suggesting that the symmetrical structure reduces the activation energy for IMT by decreasing thermodynamic energy. These results demonstrate that structural symmetry plays a crucial role in lowering the transition temperature.
Original language | English |
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Article number | 2000874 |
Journal | Advanced Electronic Materials |
Volume | 7 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2021 |
Bibliographical note
Funding Information:Y.C. and D.L. contributed equally to this work. This study was supported in part by NRF‐Korea (NRF‐2018R1D1A1B07045663 and NRF‐2020K1A3A7A09077715).
Funding Information:
Y.C. and D.L. contributed equally to this work. This study was supported in part by NRF-Korea (NRF-2018R1D1A1B07045663 and NRF-2020K1A3A7A09077715).
Publisher Copyright:
© 2021 Wiley-VCH GmbH
Keywords
- activation energy
- local structural symmetry
- phase transitions
- VO