原文
Oxides with the cubic fluorite structure, e.g., ceria (CeO2), areknown to be good solid electrolytes when they are doped withcations of lower valence than the host cations. The high ionicconductivity of doped ceria makes it an attractive electrolyte forsolid oxide fuel cells, whose prospects as an environmentallyfriendly power source are very promising. In these electrolytes, thecurrent is carried by oxygen ions that are transported by oxygenvacancies, present to compensate for the lower charge of thedopant cations. Ionic conductivity in ceria is closely related tooxygen-vacancy xxxxation and migration properties. A clear phys-ical picture of the connection between the choice of a dopant andthe improvement of ionic conductivity in ceria is still lacking. Herewe present a quantum-mechanical first-principles study of theinfluence of different trivalent impurities on these properties. Ourresults reveal a remarkable correspondence between vacancyproperties at the atomic level and the macroscopic ionic conduc-tivity. The key parameters comprise migration barriers for bulkdiffusion and vacancy–dopant interactions, represented by asso-ciation (binding) energies of vacancy–dopant clusters. The inter-actions can be divided into repulsive elastic and attractive elec-tronic parts. In the optimal electrolyte, these parts should balance.This finding offers a simple and clear way to narrow the search forsuperior dopants and combinations of dopants。。。。

剽文
Oxides with the cubic fluorite structure, e.g., ceria (CeO2), areknown to be good solid electrolytes when they are doped withcations of lower valence than the host cations. The high ionicconductivity of doped ceria makes it an attractive electrolyte forsolid oxide fuel cells, whose prospects as an environmentallyfriendly power source are very promising. In these electrolytes, thecurrent is carried by oxygen ions that are transported by oxygenvacancies, present to compensate for the lower charge of thedopant cations. Ionic conductivity in ceria is closely related tooxygen-vacancy xxxxation and migration properties. A clear phys-ical picture of the connection between the choice of a dopant andthe improvement of ionic conductivity in ceria is still lacking. Herewe present a quantum-mechanical first-principles study of theinfluence of different trivalent impurities on these properties. Ourresults reveal a remarkable correspondence between vacancyproperties at the atomic level and the macroscopic ionic conduc-tivity. The key parameters comprise migration barriers for bulkdiffusion and vacancy–dopant interactions, represented by asso-ciation (binding) energies of vacancy–dopant clusters. The inter-actions can be divided into repulsive elastic and attractive elec-tronic parts. In the optimal electrolyte, these parts should balance.This finding offers a simple and clear way to narrow the search forsuperior dopants and combinations of dopants。。。。