Stable rhombohedral stacking with almost pure GST124 on substrate miscut.(a) Raman spectra of 70 nm-thick GST grown on Si (111) with β= 0.03 at RT (black), β= 4 at RT (red) and β= 4 at 10 K (dark red).(b) Intensity ratio of the second order XRD for the VL peak and GST peak (IVL/IGST) as a function of the Raman shift for the A 1 (1)(full squares) and A 1 (2)(empty squares) modes with β= 0.03 (black), 3 (green), 4 (red) and 6 (blue). Dashed and solid lines serve as a guide to the eye. The top and bottom right panels show the Raman shift of the A 1 (1) and A 1 (2) modes, respectively.(c) 70 nm-(red) or 7 nm-(light blue) thick GST grown on Si (111) with β= 4.