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The synthesis of ZrO_2 by mechanochemical reaction using ZrCI_4 and CaO as raw materials and subsequent annealing of the products were investigated.The effect of thermal treatment on the structural evolution and morphological characteristics of the nanopowders was studied by X-ray diffractometry,Raman spectroscopy,transmission electron microscopy,scanning electron microscopy,differential thermal analysis and Rietveld refinement.The results showed that the average crystallite size of ZrO_2 was less than 100 nm up to around1100 ℃.The activation energy for ZrO_2 nanocrystallite growth during calcination was calculated to be about13,715 and 27,333 J/mol for tetragonal(t-ZrO_2) and monoclinic(m-ZrO_2) polymorphs,respectively.Mechanism of the nanocrystallite growth of the ZrO_2 polymorphs during annealing is primarily investigated.
The synthesis of ZrO_2 by mechanochemical reaction using ZrCI_4 and CaO as raw materials and subsequent annealing of the products were investigated. The effect of thermal treatment on the structural evolution and morphological characteristics of the nanopowders was studied by X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, differential thermal analysis and Rietveld refinement. The results showed that the average crystallite size of ZrO 2 was less than 100 nm up to around 1100 ° C. The activation energy for ZrO 2 nanocrystallite growth during calcination was calculated to be about 13,715 and 27,333 J / mol for tetragonal (t-ZrO 2) and monoclinic (m-ZrO 2) polymorphs, respectively. Mechanism of the nanocrystallite growth of the ZrO 2 polymorphs during annealing is primarily investigated.