Figure 3.

Lorentz fitting results for the Raman spectra in the range from 520 cm⁻¹ to 720 cm⁻¹ measured at various temperatures for samples Th90 (a) and Th150 (b), respectively. (Black dots are the original data, black lines are the Lorentz fitting line, purple lines indicate the E_g mode of sapphire, red lines indicate the A_g mode of the M1 phase of VO₂, and blue lines indicate the A_g mode of the M2 phase of VO₂.)