Data from: 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
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 > 8 S/m. Our results can be
tested with future observations from the ESA-JAXA Bepi-Colombo mission.