Journal article

Publication year: 2024

Pages: 923-938

Journal: Journal of Raman Spectroscopy

Volume number: 55

Issue number: 8

ISSN: 0377-0486

eISSN: 1097-4555

DOI Link: https://doi.org/10.1002/jrs.6684

Publisher: Wiley

Abstract: 
Vanadium dioxide (VO2) undergoes a reversible first-order metal-to-insulator transition (MIT) from a high-temperature metallic phase to a low-temperature insulating phase at a critical temperature T-c of 68 degrees C. The MIT is accompanied by a structural phase transition. In addition to the metallic high-temperature rutile phase, several insulating phases may be involved depending on doping, interfacial stress, or external stimuli. Unambiguously identifying the crystal phases involved in the phase transition is of key interest from the point of view of application as well as fundamental science. We study the impact of Ti doping of VO2 thin films on (110) rutile TiO2 substrates. We conduct a careful analysis of structural properties by combining results of x-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The transition temperature T-c of the deposited thin films decreases with increasing Ti-content. All our thin film samples undergo a structural phase transition from the monoclinic M-1-phase to the rutile R-phase with increasing temperature without passing the intermediate monoclinic M-2-phase. A careful analysis of polarization and angle-dependent Raman data reveals that, above T-c, the unit cell of the high-temperature rutile TixV1-xO2 phase is aligned with that of the rutile TiO2 substrate whereas, below T-c, 180 degrees-domains of the M-1-phase of TixV1-xO2 are observed. The structural relationship between TiO2 substrate and the high respective low-temperature phase of the TixV1-xO2 determined by Raman spectroscopy is in excellent agreement with TEM results on these samples. Raman spectroscopy is a powerful tool for studying structural changes of VO2-based samples in the vicinity of MIT.

Harvard Citation style: Kuhl, F., Lu, H., Becker, M., Chen, L., Zheng, Y., Polity, A., et al. (2024) Raman scattering of Ti_xV_1-xO₂ thin films on (110) rutile TiO₂ in the low and high temperature phase adjacent to the metal-insulator transition, Journal of Raman Spectroscopy, 55(8), pp. 923-938. https://doi.org/10.1002/jrs.6684

APA Citation style: Kuhl, F., Lu, H., Becker, M., Chen, L., Zheng, Y., Polity, A., Zhang, Z., He, Y., & Klar, P. (2024). Raman scattering of Ti_xV_1-xO₂ thin films on (110) rutile TiO₂ in the low and high temperature phase adjacent to the metal-insulator transition. Journal of Raman Spectroscopy. 55(8), 923-938. https://doi.org/10.1002/jrs.6684