1 Search Results

The melting behavior and transport properties of MgSiO₃ at multi-megabar pressures remain poorly constrained despite their importance for high-pressure silicate physics. Here we report the first direct measurements of temperature and optical reflectivity in shock-compressed bridgmanite (MgSiO₃) using laser-driven decaying shock compression combined with velocimetry and optical pyrometry. Temperature and reflectivity data spanning approximately 4000–60 000 K were used to constrain the MgSiO₃ melting curve and to infer its electrical conductivity. We find that the MgSiO₃ melting curve becomes shallower than that of iron above 400 GPa, yielding lower melting temperatures in planetary mantles than predicted by several previous theoreticalmore » estimates. Across the solid-liquid transition, the inferred electrical conductivity increases significantly, reaching ∼2000 Ω cm⁻¹. These results provide experimental benchmarks for theoretical models of silicate melting and transport under extreme pressure-temperature conditions.« less