Figure 2

Raman spectra and dispersion. (a) Raman spectra of samples B₀₀₁ and B₁₁₃ (blue and red curves, respectively) measured in acoustic spectral range with excitation wavelength of 514.5 nm. (b) Dispersion of folded LA and QLA phonons calculated for samples B₀₀₁ and B₁₁₃ with nominal thickness (blue and red curves, respectively). A horizontal line and solid blue symbols indicate the value of the scattering wave vector used in the Raman experiment and the frequencies of the folded LA phonons.