Electrical properties of alkaline earth sulfides and implications for the interior of mercury

Alkaline earth sulfides are possibly abundant in the mantle of Mercury, and knowledge of their melting and transport properties is needed to investigate the structure of the planet. We report electrical experiments at 2 and 5 GPa and up to ~2400 K on analogs of natural sulfides, i.e., impurity-bearing Ca1-xMgxS. Electrical conductivity increases nonuniformly with temperature, with no systematic effect of composition. Below 1700 K, the conductivities span a wide range, whereas at higher temperatures the samples show a convergence to a range of ~0.5-7 S/m at 1800 K and 5 GPa. The complex conductivity trends reflect contributions from divalent cations, alkali metal and carbon impurities, which would similarly contribute to the conductivity of Mercury's crust and mantle. Melting is identified by a jump in conductivity, occurring between ~1850 and 2100 K at 5 GPa. These low temperatures are consistent with the presence of impurities. Using electrical studies on relevant silicate minerals and..., The electrical data (electrical resistance R) were measured at each temperature using an impedance spectrometer (1260 Solartron Impedance/Gain Phase Analyze). To measure the complex impedance, a potential with DC component 0.1 V and AC amplitude ≤ 1 V was applied from 5 MHz to ~1 Hz. The electrical conductivity EC is calculated using the equation 
EC=1/[R⨯G] 
with G the geometric factor (electrode disk area/sample thickness). Minor contributions to the measured bulk resistance from the middle alumina ring and the electrode disks were subtracted. , , # Data from: Electrical properties of alkaline earth sulfides and implications for the interior of mercury

Electrical data collected in manuscript 2024JE008651 entitled “Electrical Properties of Alkaline Earth Sulfides and Implications for the Interior of Mercury” by A. Pommier, M. J. Tauber, C. Renggli, C. Davies, and A. Wilson (JGR-Planets).

The spreadsheet lists all the electrical measurements collected for the manuscript.

Each tab corresponds to a sulfide composition (CaS-MgS system). Experiment number starts with \"BBC\", and for each experiment, a table lists the temperature and electrical data.

The reader is referred to the manuscript for details about the experimental procedures and results.

#### **## Description of the data and file structure**

Seven samples were studied, corresponding to seven tabs: CaS (lab-synthesized), commercial CaS, Ca0.8Mg0.2S, Ca0.6Mg0.4S, Ca0.4Mg0.6S, Ca0.2Mg0.8S, and MgS.

For each experiment, the corresponding table lists the temperature (in deg ...