Fig. 2

a Raman spectra of the as-received and annealed ISG fibers, and of ISG cooled at 10 K min⁻¹. The inset shows the fit of the bands around 1000 cm⁻¹ and 1400 cm⁻¹. b, c Intensity ratios as a function of cooling rate of the peaks (b) at 1360 cm⁻¹ over the one at 1445 cm⁻¹ and (c) at 970 cm⁻¹ over the one at 1070 cm⁻¹. The error bars were taken as the standard deviation for the Gaussian fitting of the related peaks