Metallization of Shock-Compressed Liquid Ammonia

Ammonia is predicted to be one of the major components in depths ice giant planets Uranus and Neptune. Their dynamics, evolution, interior structure are insufficiently understood models rely imperatively on data for equation state transport properties. Despite its great significance, experimentally accessed region ammonia phase diagram today still very limited pressure temperature. Here we push probed regime unprecedented conditions, up $\sim$350 GPa $\sim$40000 K. Along Hugoniot, temperature measured as a function shows subtle change slope at $\sim$7000 K $\sim$90 GPa, agreement with ab initio simulations have performed. This feature coincides gradual transition from molecular liquid plasma state. Additionally, performed reflectivity measurements, providing first experimental evidence electronic conduction high-pressure ammonia. Shock reflectance continuously rises above 50 reaches saturation values 120 GPa. Corresponding electrical conductivity 1 order magnitude higher than water 100 regime, possible significant contributions ammonia-rich layers generation magnetic dynamos interiors.