start-ver=1.4 cd-journal=joma no-vol=50 cd-vols= no-issue=3 article-no= start-page=19 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230701 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Sound velocity and elastic properties of Fe–Ni–S–Si liquid: the effects of pressure and multiple light elements en-subtitle= kn-subtitle= en-abstract= kn-abstract=Fe–Ni–S–Si alloy is considered to be one of the plausible candidates of Mercury core material. Elastic properties of Fe–Ni–S–Si liquid are important to reveal the density profile of the Mercury core. In this study, we measured the P-wave velocity (VP) of Fe–Ni–S–Si (Fe73Ni10S10Si7, Fe72Ni10S5Si13, and Fe67Ni10S10Si13) liquids up to 17 GPa and 2000 K to study the effects of pressure, temperature, and multiple light elements (S and Si) on the VP and elastic properties.
The VP of Fe–Ni–S–Si liquids are less sensitive to temperature. The effect of pressure on the VP are close to that of liquid Fe and smaller than those of Fe–Ni–S and Fe–Ni–Si liquids. Obtained elastic properties are KS0 = 99.1(9.4) GPa, KS’ = 3.8(0.1) and ρ0 =6.48 g/cm3 for S-rich Fe73Ni10S10Si7 liquid and KS0 = 112.1(1.5) GPa, KS’ = 4.0(0.1) and ρ0=6.64 g/cm3 for Si-rich Fe72Ni10S5Si13 liquid. The VP of Fe–Ni–S–Si liquids locate in between those of Fe–Ni–S and Fe–Ni–Si liquids. This suggests that the effect of multiple light element (S and Si) on the VP is suppressed and cancel out the effects of single light elements (S and Si) on the VP. The effect of composition on the EOS in the Fe–Ni–S–Si system is indispensable to estimate the core composition combined with the geodesy data of upcoming Mercury mission. en-copyright= kn-copyright= en-aut-name=YamadaIori en-aut-sei=Yamada en-aut-mei=Iori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TerasakiHidenori en-aut-sei=Terasaki en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UrakawaSatoru en-aut-sei=Urakawa en-aut-mei=Satoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KondoTadashi en-aut-sei=Kondo en-aut-mei=Tadashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MachidaAkihiko en-aut-sei=Machida en-aut-mei=Akihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TangeYoshinori en-aut-sei=Tange en-aut-mei=Yoshinori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=HigoYuji en-aut-sei=Higo en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Department of Earth and Space Science, Osaka University kn-affil= affil-num=2 en-affil=Department of Earth Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Earth Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Earth and Space Science, Osaka University kn-affil= affil-num=5 en-affil=Synchrotron Radiation Research Center, National Institutes for Quantum Science and Technology (QST) kn-affil= affil-num=6 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= affil-num=7 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= en-keyword=Fe alloy kn-keyword=Fe alloy en-keyword=Sound velocity kn-keyword=Sound velocity en-keyword=Liquid kn-keyword=Liquid en-keyword=Core kn-keyword=Core en-keyword=Mercury kn-keyword=Mercury en-keyword=Light element kn-keyword=Light element END start-ver=1.4 cd-journal=joma no-vol=311 cd-vols= no-issue= article-no= start-page=106640 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210228 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Thermocapillary effects in two-phase medium and applications to metal-silicate separation en-subtitle= kn-subtitle= en-abstract= kn-abstract= The separation of a liquid phase from a solid but deformable matrix made of mineral grains is controlled at small scale by surface tension. The role of interfacial surface tension is twofold as it explains how a small volume of liquid phase can infiltrate the grain boundaries, be distributed and absorbed in the matrix, but after complete wetting of the grains, surface tension favors the self-separation of the liquid and solid phases. Another consequence of surface tension is the existence of Marangoni forces, which are related to the gradients of surface tension that are are usually due to temperature variations. In this paper, using a continuous multi-phase formalism we clarify the role of these different effects and quantify their importances at the scale of laboratory experiments and in planets. We show that Marangoni forces can control the liquid metal-solid silicate phase separation in laboratory experiments. The Marangoni force might help to maintain the presence of metal at the surface of asteroids and planetesimals that have undergone significant melting. en-copyright= kn-copyright= en-aut-name=RicardYanick en-aut-sei=Ricard en-aut-mei=Yanick kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=LabrosseStéphane en-aut-sei=Labrosse en-aut-mei=Stéphane kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TerasakiHidenori en-aut-sei=Terasaki en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=BercoviciDavid en-aut-sei=Bercovici en-aut-mei=David kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Université de Lyon, ENSL, UCBL, Laboratoire LGLTPE kn-affil= affil-num=2 en-affil=Université de Lyon, ENSL, UCBL, Laboratoire LGLTPE kn-affil= affil-num=3 en-affil=Okayama University, Department of Earth Sciences kn-affil= affil-num=4 en-affil=Yale University, Department of Earth & Planetary Sciences kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240310 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Wetting property of Fe‐S melt in solid core: Implication for the core crystallization process in planetesimals en-subtitle= kn-subtitle= en-abstract= kn-abstract=In differentiated planetesimals, the liquid core starts to crystallize during secular cooling, followed by the separation of liquid–solid phases in the core. The wetting property between liquid and solid iron alloys determines whether the core melts are trapped in the solid core or they can separate from the solid core during core crystallization. In this study, we performed high-pressure experiments under the conditions of the interior of small bodies (0.5–3.0 GPa) to study the wetting property (dihedral angle) between solid Fe and liquid Fe-S as a function of pressure and duration. The measured dihedral angles are approximately constant after 2 h and decrease with increasing pressure. The dihedral angles range from 30° to 48°, which are below the percolation threshold of 60° at 0.5–3.0 GPa. The oxygen content in the melt decreases with increasing pressure and there are strong positive correlations between the S + O or O content and the dihedral angle. Therefore, the change in the dihedral angle is likely controlled by the O content of the Fe-S melt, and the dihedral angle tends to decrease with decreasing O content in the Fe-S melt. Consequently, the Fe-S melt can form interconnected networks in the solid core. In the obtained range of the dihedral angle, a certain amount of the Fe-S melt can stably coexist with solid Fe, which would correspond to the “trapped melt” in iron meteorites. Excess amounts of the melt would migrate from the solid core over a long period of core crystallization in planetesimals. en-copyright= kn-copyright= en-aut-name=MatsubaraShiori en-aut-sei=Matsubara en-aut-mei=Shiori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TerasakiHidenori en-aut-sei=Terasaki en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YoshinoTakashi en-aut-sei=Yoshino en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UrakawaSatoru en-aut-sei=Urakawa en-aut-mei=Satoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YumitoriDaisuke en-aut-sei=Yumitori en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Department of Earth Sciences, Graduate School of Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Department of Earth Sciences, Graduate School of Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=Department of Earth Sciences, Graduate School of Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Department of Earth Sciences, Graduate School of Science and Technology, Okayama University kn-affil= END