Chem. Commun., 2020,56, 4882-4885. https://doi.org/10.1039/D0CC01429J

We report for the first time the discovery of reversible n–p conduction type switching in a chalcogenide, NaCu₅S₃, without structural transition. AC impedance and first-principles simulations of the ionic migration confirmed the local melting trends of the hexagonal copper lattice at high temperatures, which could result in superionic conductivity within NaCu₅S₃.