{"title":"Sound velocity and density of liquid Ni68S32 under pressure using ultrasonic and X-ray absorption with tomography methods","authors":"Hidenori Terasaki , Keisuke Nishida , Satoru Urakawa , Yusaku Takubo , Soma Kuwabara , Yuta Shimoyama , Kentaro Uesugi , Yoshio Kono , Akihisa Takeuchi , Yoshio Suzuki , Yuji Higo , Tadashi Kondo","doi":"10.1016/j.crte.2018.04.005","DOIUrl":null,"url":null,"abstract":"<div><p>A new experimental setup for simultaneous P-wave velocity (<em>V</em><sub>P</sub>) and density (<em>ρ</em>) measurements for liquid alloys is developed using ultrasonic and X-ray absorption methods combined with X-ray tomography at high pressures and high temperatures. The new setup allows us to directly determine adiabatic bulk moduli (<em>K</em><sub>S</sub>) and to discuss the correlation between the <em>V</em><sub>P</sub> and <em>ρ</em> of the liquid sample. We measured <em>V</em><sub>P</sub> and <em>ρ</em> of liquid Ni<sub>68</sub>S<sub>32</sub> up to 5.6<!--> <!-->GPa and 1045<!--> <!-->K using this technique. The effect of pressure on the <em>V</em><sub>P</sub> and <em>ρ</em> values of liquid Ni<sub>68</sub>S<sub>32</sub> is similar to that of liquid Fe<sub>57</sub>S<sub>43</sub>. (Both compositions correspond to near-eutectic ones.) The obtained <em>K</em><sub>S</sub> values are well fitted to the finite strain equation with a <span><math><mrow><msub><mi>K</mi><mrow><msub><mtext>S</mtext><mn>0</mn></msub></mrow></msub></mrow></math></span> value (<em>K</em><sub>S</sub> at ambient pressure) of 31.1<!--> <!-->GPa and a d<em>K</em><sub>S</sub>/d<em>P</em> value of 8.44. The measured <em>V</em><sub>P</sub> was found to increase linearly with increasing <em>ρ</em>, as approximated by the relationship: <em>V</em><sub>P</sub> [m/s]<!--> <em>=</em> <!-->1.29<!--> <em>ρ</em> [kg/m<sup>3</sup>] – <em>5726</em>, suggesting that liquid Ni–S follows an empirical linear relationship, Birch's law. The d<em>V</em><sub>P</sub>/d<em>ρ</em> slope is similar between Ni<sub>68</sub>S<sub>32</sub> and Fe<sub>57</sub>S<sub>43</sub> liquids, while the <em>V</em><sub>P</sub>–<em>ρ</em> plot of liquid Ni–S is markedly different from that of liquid Fe–S, which indicates that the effect of Ni on Birch's law is important for understanding the <em>V</em><sub>P</sub>–<em>ρ</em> relation of planetary and Moon's molten cores.</p></div>","PeriodicalId":50651,"journal":{"name":"Comptes Rendus Geoscience","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crte.2018.04.005","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comptes Rendus Geoscience","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1631071318300531","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 1
Abstract
A new experimental setup for simultaneous P-wave velocity (VP) and density (ρ) measurements for liquid alloys is developed using ultrasonic and X-ray absorption methods combined with X-ray tomography at high pressures and high temperatures. The new setup allows us to directly determine adiabatic bulk moduli (KS) and to discuss the correlation between the VP and ρ of the liquid sample. We measured VP and ρ of liquid Ni68S32 up to 5.6 GPa and 1045 K using this technique. The effect of pressure on the VP and ρ values of liquid Ni68S32 is similar to that of liquid Fe57S43. (Both compositions correspond to near-eutectic ones.) The obtained KS values are well fitted to the finite strain equation with a value (KS at ambient pressure) of 31.1 GPa and a dKS/dP value of 8.44. The measured VP was found to increase linearly with increasing ρ, as approximated by the relationship: VP [m/s] = 1.29 ρ [kg/m3] – 5726, suggesting that liquid Ni–S follows an empirical linear relationship, Birch's law. The dVP/dρ slope is similar between Ni68S32 and Fe57S43 liquids, while the VP–ρ plot of liquid Ni–S is markedly different from that of liquid Fe–S, which indicates that the effect of Ni on Birch's law is important for understanding the VP–ρ relation of planetary and Moon's molten cores.
期刊介绍:
Created in 1835 by physicist François Arago, then Permanent Secretary, the journal Comptes Rendus de l''Académie des sciences allows researchers to quickly make their work known to the international scientific community.
It is divided into seven titles covering the range of scientific research fields: Mathematics, Mechanics, Chemistry, Biology, Geoscience, Physics and Palevol. Each series is led by an editor-in-chief assisted by an editorial committee. Submitted articles are reviewed by two scientists with recognized competence in the field concerned. They can be notes, announcing significant new results, as well as review articles, allowing for a fine-tuning, or even proceedings of symposia and other thematic issues, under the direction of invited editors, French or foreign.