Experimental indications of superionic behaviour in iron hydride under Earth’s core conditions (opens in new tab)

Earth’s inner core is believed to consist of an iron–light-element alloy such as iron hydride (FeHX). The possibility that a superionic state may emerge in the inner core has recently gained attention as a physico-chemical phenomenon for explaining its seismological properties, such as slow shear-wave velocities and seismic anisotropy. Despite theoretical predictions, direct experimental evidence for superionic behaviour in iron–light-element alloys remains scarce. Here we present in situ, ti...