Mechanical stress effect on oxygen ion mobility in 8 mol% yttria-stabilized zirconia electrolyte

In the present study, the effect of mechanical tensile stress on oxygen mobility in 8 mol% yttria-stabilized zirconia (8YSZ) was investigated. The experimental results show that the ionic conductivity increases with stress and saturates. The maximum improvement in the conductivity was about 18% observed at 973 K. The simulation results show that the diffusion coefficient increases with stress and decreases with excessive stress. The maximum improvement was about 40% observed at 973 K. The improvement was larger at lower temperatures in both the experiment and the simulation. The strain caused by the stress is considered to have caused the gradient in the potential energies of the neighbouring oxygen sites, especially around the yttrium ions, which probably facilitated the migration of the oxygen ions. (C) 2009 Elsevier Ltd. All fights reserved.