Transient superionic state in ultrafast-irradiated post-transition metal oxides

Résumé fourni par la source

Abstract Matter under irradiation may enter unusual transient states, outside of its equilibrium phase diagram. One such state is a superionic-like state, in which one sublattice of a compound liquifies, whereas another one remains solid. Here, we study theoretically post-transition metal oxides under ultrafast excitation of their electronic system, identifying which compounds produce such a superionic state. It is shown that oxides with sufficiently sparse metallic sublattices (e.g., corundum structure) generally form transient superionic states via nonthermal phase transition. More closely packed lattices (such as the zinc-blende structure in ZnO and CdO) do not exhibit superionicity. Tl and Pb oxides only enter thermally produced superionic states (induced by atomic heating via electron-phonon coupling), but not nonthermal ones. Sn and Bi oxides demonstrate states that cannot be clearly classified, in which the oxygen subsystem diffuses significantly more and faster than the metallic one, but the metallic one is not stable as it would be in a truly superionic state.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.