Synthesis of nanostructure tetragonal ZrO2 by high energy ball milling

Phase transformation of monoclinic ZrO2 to tetragonal and cubic ZrO2 was successfully performed during ball milling. X-ray diffraction and high temperature in situ X-ray diffraction were performed to study the progressing of this transformation. Quantity phase analysis, crystallite size and microstrain were calculated by the Rietveld refinement method. Morphology and microstructure were monitored by scanning and transmission election microscopy respectively. The results showed that this transformation was initiated after 30 h milling and progressed gradually at longer milling times. Longer milling led to the smaller crystallites with larger microstrain, which were proposed as the mechanism of stabilisation of tetragonal and cubic ZrO2 at room temperature. A nanostructure powder with a mean crystallite size of <10 nm was obtained at the end of milling on the basis of the Rietveld method, which was confirmed by transmission electron microscopic images.