Synthesis of bismuth ferrite lead titanate nano-powders and ceramics using chemical co-precipitation

The high temperature ferroelectric material BiFeO3–PbTiO3 was fabricated via chemical co-precipitation using Bi(NO3)3·(H2O)5, Fe(NO3)3·(H2O)9, Pb(NO3)2 and TiI4 as precursors. The prepared composition was close to the target composition, as determined by XRF and EDX. Calcination at 800 °C yielded a single phase powder, with a primary particle size in the range 20–75 nm, and were single crystallites, as determined using TEM. Pellets fabricated from the powder were sintered to a maximum density at 950 °C, some 65–75 °C lower than using a conventional mixed oxide route, and had a density of 95% of theoretical. The sintered pellets had a relative permittivity of 190 compared to 280 for conventionally prepared materials.