(a) DSC thermograms for two distinct temperature protocols as demonstrated on the aqueous ZnCl₂ solution with X_aqu = 0.61 and the solution with X_aqu = 0.49 for comparison. Protocol 1 (black line and blue line): conventional cooling/heating process; protocol 2 (red line): the heating process is interrupted at 208 K. After being maintained there for 1 min to complete recrystallization, the sample was again cooled down to 123 K and then heated to room temperature (emphasized with a dashed line). The curves are defaulted each by 0.3 mW/mg for clarity. (b) Raman spectra for the aqueous ZnCl₂ solution with X_aqu = 0.61 at 298 K (black dashed line), and for pure ice at 183 K (blue dotted line). The difference spectrum (red solid line) refers to difference in measurements at 183 K on the solution before and after recrystallization.