Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases

Journal Article · Mon Apr 21 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4870868· OSTI ID:22273579

Okimura, Kunio; Hanis Azhan, Nurul ^[1]; Hajiri, Tetsuya ^[2]; Kimura, Shin-ichi ^[2]; Zaghrioui, Mustapha; Sakai, Joe ^[3]

---

1. Graduate School of Engineering, Tokai University, Hiratsuka 259-1292 (Japan)
2. UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan)
3. GREMAN, UMR 7347 CNRS, Université François Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195 cm{sup −1} (V-V vibration) and 616 cm{sup −1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPS spectra with high energy resolution of 0.03 eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.

• OSTI ID: 22273579
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPARATIVE EVALUATIONS
ELECTRON SPECTRA
ENERGY RESOLUTION
PHASE TRANSFORMATIONS
PHOTOELECTRON SPECTROSCOPY
POLYCRYSTALS
RAMAN SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
ULTRAVIOLET RADIATION
VANADIUM OXIDES