| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1277165 | International Journal of Hydrogen Energy | 2012 | 7 Pages |
Densification and micro-structural development of ultra fine 8 mol% yttria stabilized zirconia (8YSZ) nano powder were investigated systematically by varying the SPS sintering temperature at constant applied pressure of 50 MPa. A hundred fold decrease in average grain size ranging from 10 μm to 80 nm is observed on decreasing the SPS sintering temperature from 1200 °C to 1050 °C with >99% of theoretical densities. Impedance measurements on the samples indicated an enhancement in the ionic conductivity at 700 °C from 0.004 S/cm to 0.018 S/cm with decrease in grain size from 10 μm to 0.51 μm and a significant increase in conductivity from 0.018 S/cm to 0.068 S/cm on further reduction of grain size to 80 nm. A significant change in the grain-boundary conductivity is noticed on reducing the grain sizes to nano regime. The diverse microstructure with ultra fine grain size resulting from SPS at 1050 °C could contribute to the enhanced ionic conductivity, which is supported by the activation energy data.
► Low temperature SPS densification of 8YSZ electrolytes retaining nano grains. ► Sintered 8YSZ close to TD with nano grains exhibited high ionic conductivity. ► Potential exists for SPS sintered 8YSZ for intermediate temperature application.
