Figure 1: Heat capacity c_p of Vit.1.

(a) c_p of an amorphous sample is measured upon heating at 50 K min⁻¹. Solid circles represent the glassy, supercooled liquid and stable liquid states; the dashed curve indicates the crystallization and melting processes. Note that there is a heat capacity peak at around 1,100–1,200 K, which occurs in the molten liquid according to the in situ XRD taken at a 10 times higher heating rate (~9 K s⁻¹) (see Fig. 2). Inset shows the magnification of the c_p peak (1,100–1,200 K) where the solid circles and open squares represent two separate measurements (vertically shifted for clarity). The arrows indicate that there is a small subpeak on the left shoulder of the main peak. In the lower part of the figure, the dash-dot curve shows the heat capacity during cooling of Vit.1 taken from c_p/ε_T in Ohsaka et al.³⁵ (assuming the emissivity³⁵ ε_T=0.18), which is here plotted as negative values to indicate the exothermic event around 700–800 K in the supercooled liquid region in reference to the baseline (dotted curve) (see Discussion). (b) c_p measured upon heating at 30 K min⁻¹ for the amorphous sample (upper) and once-melted crystallized sample (lower) (vertically shifted for clarity). The arrow shows the small subpeak separated from the main peak to a lower temperature.