DOI: 10.5061/dryad.nk98sf82m
title: Data from: Electrical properties of alkaline earth sulfides and implications for the interior of mercury

description: 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
 petrological observations, we develop electrical conductivity-depth
 profiles of Mercury's mantle. Depending on the interconnectivity of
 the sulfide phase, the conductivity at the base of the mantle containing 8
 vol.% sulfide ranges from ~0.2 to &gt; 8 S/m. Our results can be
 tested with future observations from the ESA-JAXA Bepi-Colombo mission.
description: 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. 
description: # 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 C and K), the inverse temperature, the electrical
 resistance R (ohm) and the electrical conductivity EC (in S/m).