Ionic Conductivity in Uniaxial Micro Strain/Stress Fields of Yttria-Stabilized Zirconia

The influence of uniaxial compressive strain/stress on the O2- ion conductivity of an yttria-stabilized zirconia (YSZ) sample was investigated by using electrochemical measurement. The conductivity was investigated by the AC four-probe method and molecular dynamics simulation. The applied compressive strain/stress ranged from 0 to 0.0003 (stress: 1.5-55 MPa) for the specimen in air at 873, 973, and 1073 K. To clarify the reason for the phenomenon of the decline in conductivity, the relaxation time for the conductivity after the application of strain/stresses was measured. The experimental result revealed that as the applied compressive strain/stress increases, the carrier concentration remains steady, whereas the mobility decreases. The conductivity was decreased with increasing compressive strain, and this trend agreed with that of the simulation results. Therefore, the decrease in mobility was considered to be the reason for the decline in conductivity under compressive strain/stress conditions. (C) 2011 The Japan Society of Applied Physics