Ferroelectric perovskite nanopowders obtained by mechanochemical synthesis

Simple perovskite nanopowders were fabricated by mechanochemical synthesis. High-energy milling process of respective oxides, leading to production of ferroelectric perovskites, was carefully investigated and characterized by X-ray diffraction, electron microscopy and X-ray excited photoelectron spectroscopy. It has been found that: (i) the powder consists of loosely packed grains with a broad distribution of sizes between a few nm and 45 nm, (ii) the grains possess core/shell structure, (iii) the grain core of sizes larger than about 20 nm exhibits well developed crystalline structure, (iv) the grains are coated by structurally disordered (amorphous) shell. Intermediate phases have been found in the process of PbTiO3 mechanosynthesis only. The obtained nanopowders were used for preparation of dense ceramics