Nanocrystallines of calcia-stabilized zirconia are known to reveal excellent mechanical and high ionic conductivity propertieswhose depend on the calcia concentration. In this work, nanocrystallines of calcia-stabilized zirconia were synthesized fromzircon precursor and 7.5 weight % CaO at 1000 oC, 1200 oC, and 1400 oC. Phase transformation and microstructure evolutionwere investigated by an X-ray diffraction and a scanning electron microscopy. Another un-doped zirconia was also synthesizedfrom the local zircon by following the same procedure for comparison. A fully cubic form of the calcia-stabilized zirconia andcalcium zirconate were obtained at 1200°C having the crystallite sizes ranging from 55 to 87 nm and remained stable at1400 oC. Meanwhile, un-doped zirconia consisted of pure the monoclinic zirconia at 1200 oC and 1400 oC. High agglomerationis found in the calcia-stabilized zirconia particles at 1000 oC, whereas grain boundaries and interconnect are observed at1400 oC. The cubic crystal of zirconia has specific and different finger print characteristics in the infra-red spectrum comparedto the monoclinic zirconia.

Keywords: 7.5 wt% calcia-stabilized zirconia, Zircon, Slaked lime, Phase alteration and Microstructure evolution