Preparation and structural stability of ordered nanocomposites: opal matrix - lead titanates

Abstract

The conditions for the formation of nanocomposites based on the basis of lattice packings of SiO[2] nanospheres (opal matrices) with included crystallites of lead titanates (PbTiO[3] and PbTi[3]O[7]) in interspherical nanospacing are considered. For the formation of nanocomposites are used sample opal matrices with dimensions of single-domain regions >=0,1 mm.{3} The diameter of SiO[2] nanospheres was ~260 nm. Obtained nanocomposites volume >2 cm{3} in filling >20% of interspherical nanospacing PbTiO[3], PbTi[3]O[7] crystallites were size of 16-36 nm. Using X-ray diffraction and Raman spectroscopy are studied composition and structural stability when heated nanocomposites to 550°C, which allowed the identification of a local phase transition with change of the space group. The dependence of the composition of synthesized materials on the conditions of their preparation is submitted.