Articles
  • Determination of partial conductivities and electrolytic domain of yttrium-doped zirconia prepared from Indonesian zircon sand
  • In-Ho Kima , Bhupendra Singhb , Ji-Won Lima and Sun-Ju Songb,*
  • Ionics Lab, School of Materials Science and Engineering, 6-212 Engineering College, Chonnam National University, Gwang-Ju 61186, Koera b Department of Ceramic Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005, India
Abstract
In this work, yttrium stabilized zirconia (YSZ) was synthesized using zirconium oxychloride (ZOC) which was extracted from high-grade zircon sand mine in Indonesia. The ZOC was extracted from the zircon sand by caustic fusion method which was used to prepare 8 mole% yttrium doped zirconia (YSZ8) powder with average particle diameter of 422 nm by co-precipitation method. The powder was then granulated to ~15 μm granules by spray drying process and the granules were used to fabricate dense sintered body. The sintering temperature of 1600 oC was determined by monitoring the relative shrinkage rate with temperature. The prepared materials were analyzed by X-ray diffraction (XRD), particle size distribution and Inductively coupled plasma mass spectrometry (ICP-MS), and scanning electron microscopy (SEM). The XRD indicated that the sintered YSZ8 has a cubic structure. Total electrical conductivity of the sintered YSZ specimen was calculated in 700-900 oC and 0.21 ≤(pO2/atm)≤ 10−19 range by DC 4-probe method. The materials showed a maximum conductivity of 7.78 × 10−2 S.cm−1 at 900 oC with an activation energy of 0.83 ± 0.02 eV and the conductivity was lower than commercial 8YSZ at various temperature. The Hebb-Wagner polarization experiments were performed to measure partial electronic conductivity. The activation energies for conduction of holes and electrons were 1.48 ± 0.02 and 4.98 ± 0.94 eV, respectively. The electrolyte domain for YSZ8 was determined.

Keywords: Zircon sand, Yttrium stabilized zirconia, Hebb-Wagner ion-blocking method, Partial electronic conductivity, Electrolytic domain.

This Article

  • 2018; 19(2): 134-141

    Published on Apr 30, 2018