6456 20230428150019.0 10.1029/2022JE007577 DOI SCART-2023-0147 Zhao, Bin Local structure and density of liquid Fe-C-S alloys at Moon's core conditions 2023 The local structure and density of ternary Fe-C-S liquid alloys have been studied by the combination of in-situ X-ray diffraction and absorption experiments between 1 and 5 GPa and 1600 to 1900 K. The addition of up to 12 at{\%} of carbon (C) to Fe-S liquid alloys does not significantly modify the structure, which is largely controlled by the perturbation to the Fe-Fe network induced by S atoms. The liquid density determined from diffraction and/or absorption techniques allows us to build a non-ideal ternary mixing model as a function of pressure, temperature, and composition in terms of the content of alloying light elements. The composition of the Moon?s core is addressed based on this thermodynamic model. Under the assumption of a homogeneous liquid core proposed by two recent Moon models, the sulfur content would respectively be 27-36 wt{\%} or 12-23 wt{\%}, while the carbon content is mainly limited by the Fe-C-S miscibility gap, with an upper bound of 4.3 wt{\%}. On the other hand, if the core is partially molten, the core temperature is necessarily lower than 1850 K estimated in the text, and the composition of both the inner and outer core would be controlled by aspects of the Fe-C-S phase diagram not yet constrained well enough. 3PRODPLANINT/ 3PRODPLANINT/ 3PRODPLANINT NO Morard, Guillaume Boulard, Eglantine Boccato, Silvia Siersch, Nicki C. Rivoldini, Attilio Guignot, Nicolas Henry, Laura King, Andrew Zurkowski, Claire Fei, Yingwei Antonangeli, Daniele Journal of Geophysical Research: Planets 128 2023 3 attilio.rivoldini@observatoire.be 939017 http://publi2-as.oma.be/record/6456/files/Zhao2023aa00.pdf 21442 http://publi2-as.oma.be/record/6456/files/Zhao2023aa00.gif?subformat=icon icon 23448 http://publi2-as.oma.be/record/6456/files/Zhao2023aa00.jpg?subformat=icon-180 icon-180 published in REFERD