Adiabatic heat flow in Mercury's core from electrical resistivity measurements of liquid Fe-8.5 wt%Si to 24 GPa

Electrical Resistivity of Fe and Fe‐3 wt%P at 5 GPa With Implications for the Moon's Core Conductivity and Dynamo

“…The resistivity of Fe‐P melts has a negative T‐dependence when using molybdenum plates but a positive T‐dependence when using tungsten plates (Figure 3). Considering the success of W plates used in other studies (Berrada et al., 2021; Silber et al., 2018), the decrease in resistivity of Fe‐P melts is not representative of the sample and may be credited to the strong influence of the Mo plates. The diffusion of Mo plates into the Fe‐P sample increases as the temperature increases, and interactions between Mo plates and samples lead to a negative T‐dependence of the resistivity of melted Fe‐P‐Mo.…”

“…Unlike Fe‐P systems, Fe‐Si and Fe‐S systems have complicated phase transitions at 5 GPa and high temperature. These phase transitions also reflect changes in resistivity (Berrada et al., 2020, 2021; Littleton et al., 2021; Silber et al., 2019). The measured resistivity of Fe‐Si alloy shows a slightly negative slope after the first phase transition (Figure 3).…”

“…Ezenwa and Yoshino (2020) tested Zr and Hf as metal plates and concluded that no ideal candidate metal could serve as a mechanical barrier to avoid sample‐electrode contamination. A fast data‐collection strategy may reduce the effect of metal plate dissolution into samples as diffusion is a function of time (Berrada et al., 2021).…”

“…The solubility of W in liquid Fe‐Si alloys was also investigated as a function of temperature by Berrada et al. (2021); they found that tungsten solubility rapidly increases from ∼4 wt% to ∼14 wt% as temperature rises above the melting point. As shown in Figure S6 of Supporting Information , the diffusion of metal plates (W/Mo) in the melted Fe‐P is always larger than that of melted iron and melted Fe‐Si, suggesting that phosphorus enhances diffusion of W/Mo.…”

“…To date, numerous studies have investigated the electrical resistivities of Fe and Fe‐L systems (L is light elements, such as S, C, Si, and P) under various pressure‐temperature conditions (see the review paper of Berrada and Secco [2021]). Electrical resistivity has been used to discuss the thermal evolution of the Earth (Gomi & Hirose, 2015; Inoue et al., 2020; Ohta et al., 2016; Yong et al., 2019; Y. Zhang et al., 2020, 2021), Moon (Berrada et al., 2020; Yin, Zhai, et al., 2019), Mars (Suehiro et al., 2017), Ganymede (Littleton et al., 2021; Pommier, 2020), and Mercury (Berrada et al., 2021; Manthilake et al., 2019; Pommier, 2018; Pommier et al., 2019; Silber et al., 2018).…”