Dynamics of interacting oxygen ions in yttria stabilized zirconia: Bulk material and nanometer thin films

Abstract

The oxygen vacancy dynamics in bulk yttria-stabilized zirconia studied experimentally by conductivity relaxation and quasielastic light scattering had shown anomalous properties that had been attributed to the many-ion effects originating from ion-ion interaction. In the explanation of the anomalous properties given more than ten years ago, some predictions including the actual value of the energy barrier opposing oxygen ion hop have been made but remain unverified. Since then, many molecular dynamics simulations on oxygen vacancy dynamics in bulk YSZ have been published. Moreover, oxygen vacancy dynamics in nanometer thin films of YSZ fabricated in various fashion have been measured by conductivity relaxation as well as studied by computer simulations. This rich collection of new experimental and computer simulations results provide fertile ground for testing the predictions made before. The tests are made and the results are positive. The advance lends considerable support of the previously published explanation of oxygen vacancy dynamics in bulk YSZ. We pointed out that ion dynamics similar to YSZ are found in other ionic conductors, and the explanation for YSZ given here also works there.