Correlation between Symmetry and Phase Transition Temperature of VO2 Films Deposited on Al2O3 Substrates with Various Orientations
- 주제(키워드) activation energy , local structural symmetry , phase transitions , VO , (2)
- 주제(기타) Nanoscience & Nanotechnology
- 주제(기타) Materials Science, Multidisciplinary
- 주제(기타) Physics, Applied
- 설명문(일반) [Choi, Yesul; Lee, Dooyong; Song, Sehwan; Kim, Jiwoong; Ju, Tae-Seong; Park, Sungkyun] Pusan Natl Univ, Dept Phys, Busan 46241, South Korea; [Kim, Hyegyeong] Pusan Natl Univ, Core Res Facil, Busan 46241, South Korea; [Kim, Jiwoong; Yoon, Seokhyun] Ewha Womans Univ, Dept Phys, Seoul 03760, South Korea; [Kim, Yunseok] Sungkyunkwan Univ, Sch Adv Mat & Engn, Suwon 16419, South Korea; [Phan, Thang Bach] Ctr Innovat Mat & Architectures INOMAR, Ho Chi Minh City, Vietnam; [Bae, Jong-Seong] Korea Basic Sci Inst, Busan Ctr, Busan 46742, South Korea
- 등재 SCIE, SCOPUS
- 발행기관 WILEY
- 발행년도 2021
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000182454
- 본문언어 영어
- Published As http://dx.doi.org/10.1002/aelm.202000874
초록/요약
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.
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