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

摘要

The conditions for the formation of nanocomposites based on the basis of lattice packings of SiO2 nanospheres (opal matrices) with included crystallites of lead titanates (PbTiO3 and PbTi3O7) in interspherical nanospacing are considered. For the formation of nanocomposites are used sample opal matrices with dimensions of single-domain regions >0,1 mm. The diameter of SiO2 nanospheres was ~260 nm. Obtained nanocomposites volume >2 cm~3 in filling >20% of interspherical nanospacing PbTiO3, PbTi3O7 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.