X-ray absorption spectroscopy based investigation of local structure in yttria stabilized zirconia nanoparticles generated by laser evaporation method: Effect of pulsed vs CW mode of laser operation

Two order higher ionic conductivity was reported by us (J. Khare et al., Ceram. Int. 40 (2014) 14677) in pellet made from yttria stabilized zirconia nanoparticles grown under pulsed mode in comparison with pellets made from yttria stabilized zirconia nanoparticles grown under CW mode of CO2 laser based vaporization method. To understand possible cause of difference in conductivity, the local structure around Zr+4 ion and Y+3 ion has been investigated using X-ray absorption fine structure spectroscopy. The local structure around Zr has been found to depend on the mode of laser vaporization for nanoparticles generation. In case of pulsed mode of vaporization method the charge compensating oxygen vacancies created by the substitution of Y are preferentially forming dipole type defect configuration leading to high ionic conductivity. While formation of immobile tripole type defects are responsible for low ionic conductivity in pellets made from nanoparticles generated under CW mode of laser vaporization.