Low temperature synthesis of bismuth titanate niobate nanoparticles from polymeric precursor

Abstract

The preparation of homogeneous Bi₇Ti₄NbO₂₁ single phase ceramic nanosized powders at temperatures as low as 400°− 500°C using a metal-citrate complexes method, based on the Pechini-type reaction route, is described. The thermal decomposition/oxidation of the polymerized resin, as investigated by TG/DTA, XRD, and SEM, led to the formation of a well defined orthorhombic Bi₇Ti₄NbO₂₁ compound with lattice parameters a=0.544, b=0.540, and c=2.905 ± 0.0005 nm. Reaction formation take place through an intermediate binary phase with a stoichiometry close to Bi₂₀TiO₃₂ which formes between 300°C and 375°C. The metal-organic precursor synthesis method, allows to control the Bi/Ti/Nb stoichiometric ratio leading to the rapid formation of the nanosized bismuth titanate niobate, Bi₇Ti₄NbO₂₁, ceramic powders, at temperatures much lower than usually needed in the conventional route.

Keywords:

• Bismuth titanate niobate
• polymeric method
• nanoparticles