Rietveld refinement on XRD and TEM study of nanocrystalline PbZr_0:5Ti_0:5O₃ ceramics prepared with a soft chemistry route

PbZr_0:5Ti_0:5O₃ nanopowders (~27 nm) have been prepared by a controlled reconstructive thermal decomposition and crystallization from an amorphous polymeric precursor with polyvinyl alcohol (PVA) and sucrose at 400 to 700 °C in air. The Rietveld refinement of the XRD profiles which were recorded at room temperature for the PbZr_0:5Ti_0:5O₃ powder prepared by a thermal treatment at 700 °C for 2 h, confirmed the P4mm tetragonal crystal structure of the as prepared PbZr_0:5Ti_0:5O₃ nanopowders, with a = 0.4036 nm and c = 0.4147 nm. A hexagonal symmetry (R3c), with a = 0.5774 nm and c = 1.4212 nm, was also detected from Rietveld refinement analysis. Thus, tetragonal and hexagonal phases were found to coexist with the as prepared PbZr_0:5Ti_0:5O₃ nanopowders. The average particle size (D) of the PbZr_0:5Ti_0:5O₃ powders, estimated with the help of the specific surface area, measured by BET method, was 26.1 nm. Average D value, calculated by D2θ_1/2 in the XRD peaks with the Debye-Scherrer relation was ~24 nm. TEM study made it possible to measure the particle size of PbZr_0:5Ti_0:5O₃ powders with an average diameter of 27 nm.