Temperature and conductivity in shock compressed bridgmanite MgSiO₃ up to 2 TPa

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 theoretical estimates. Across the solid-liquid transition, the inferred electrical conductivity increases significantly, reaching \(\sim2000\ \Omega\) cm^-1. These results provide experimental benchmarks for theoretical models of silicate melting and transport under extreme pressure-temperature conditions.

Recommended citation: Huff, M. F. et al. (2026). "Temperature and conductivity in shock compressed bridgmanite MgSiO₃ up to 2 TPa." Physical Review B.
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