Fe-S-H_Data_Wei_2024

In this study, we explored the effects of varying hydrogen content on the mineralogy of Fe-S system in the laser-heated diamond-anvil cell (LHDAC) combined with <i>in-situ </i>synchrotron X-ray diffraction (XRD). With a small amount of hydrogen (≤ 0.6 wt% H), we found that Fe₃S remains stable at 30 GPa but undergoes partial decomposition at 40 GPa. As the hydrogen content increases to ~0.14 wt%, Fe₃S reacts with hydrogen, yielding FeH_x, FeS(VI), Fe_xS (x = 1/2, 3/2, or 2), and FeS_xH_y (specifically for H content ≥ 0.33 wt%). With more S in the system, both FeS and FeS₂ emerge in the reaction products with H, while FeH_x forms when H content is sufficiently high. Our study sheds light on the interplay between sulfur and hydrogen in Fe metal, offering important insights into possible Martian core mineralogies across various compositional scenarios.