Figure 8

Raman spectra of samples obtained under different undercoolings, spot1 to spot5 corresponds to the region marked in Fig. 7(e–h). Canary yellow bright area represents β-BT2 Raman peaks of 203.9 cm⁻¹ and 804.2 cm⁻¹, pink bright area represents γ-BT2 Raman peaks of 342.3 cm⁻¹ and 881.5 cm⁻¹.