Dislocation-enhanced ionic conductivity of yttria-stabilized zirconia

The ionic conductivity of yttria-stabilized zirconia (YSZ) single crystals (10 mol %Y2O3–ZrO2) was enhanced by introducing high density of dislocations. YSZ single crystals were systematically deformed by compression tests at 1300 °C, and their electrical conductivity was measured by an AC impedance method. It was confirmed that a great number of dislocations were introduced in YSZ by the high-temperature deformation, and the density reached up to more than 8×1012 m−2, depending on the compression strains imposed on the samples. The electrical conductivity of the deformed samples was found to be larger than that of undeformed samples. Furthermore, samples with larger strains exhibited higher electrical conductivity, which indicates that dislocations generated by the plastic deformation play an important role to enhance the ionic conductivity of YSZ.