Fig. 3

Phase diagram of the Fe–S–Si system in this study. Open squares show the coexistence of Fe–Si alloys (fcc + hcp) and Fe₃S detected by X-ray diffraction experiments. The open triangles show partial melting, and the solid triangles show total melting above the liquidus detected by the disappearance of X-ray diffraction patterns of the crystalline phases. The fcc phase appears as the liquidus phase at least up to 32 GPa. The bold solid and dashed lines show the solidus and liquidus curves fitted by Simon’s equation, respectively. The pressure and temperature condition of partial melting based on the quenched texture observation of the recovered sample (Fig. 2) is shown as a gray circle