Exploring the High-Pressure Crystal Chemistry of the Fe-S System

The Fe-S system is fundamental to understanding planetary interiors. In our previous high-pressure experiments at ESRF, we identified several novel iron sulfide phases on the Fe-rich side. To achieve a comprehensive understanding of the crystal chemistry of the Fe-S system under high pressure, we propose extending our previous study (ES-1529) to the sulfur-rich side of the phase diagram up to 150 GPa. Novel S-rich iron sulfide phases will be synthesized in laser-heated diamond anvil cells under extreme pressure and temperature conditions. The crystal structures of the samples will be characterized using single-crystal X-ray diffraction. Combined with our previous results, this study will, for the first time, enable the construction of a complete Fe-S phase diagram under high pressure across the entire compositional range. The findings will provide new insights into the distribution and behavior of Fe and S in planetary interiors, phase relations and crystal chemistry of Fe-S system.