Ion conductive character of low-yttria-content yttria-stabilized zirconia at low temperature

In this work, we discuss ion conductive character of low-Y2O3-content yttria-stabilized zirconia (YSZ) crystallized into high-symmetric phase (cubic and/or tetragonal phases) at relatively low temperature. Low-Y2O3-content YSZ was certainly stabilized into high-symmetric phase by extreme thinning down to around 10 nm. We analyzed the impedance response from ultra-thin YSZ films in metal/insulator/metal (MIM) capacitor measured in the temperature range of 30 °C-440 °C. It is expected that a characteristic kink on Nyquist-diagram is correlated to the conductivity of inner grain of the YSZ. The activation energy for ion conduction is monotonically reduced with decreasing Y2O3 content, whereas the conductivity still exhibits the highest value at certain Y2O3 content.