Bismuth Zinc Niobate (Bi1.5ZnNb1.5O7) Nanopowder Derived from High Energy Mechanical Activation
Bismuth zinc niobate belongs to the pyrochlore-based microwave dielectrics, with high ε and low dielectric losses. This research reports the results obtained on the bismuth zinc niobate pyrochlore (Bi1.5ZnNb1.5O7 - α-BZN) synthesis by a mechanochemically assisted method. The mechanochemical activation allows reducing the particle size of the initial products, leading to an increase in the specific surface, improving in most cases its reactivity. The effects of changing the milling parameters (ball size, speed, and length of the mechanical treatment) are discussed. The obtained powders were characterized by X-ray diffraction, thermal analysis, optical spectroscopy and scanning electron microscopy. The activated powder was annealed at temperatures ranging from 500 to 800oC. A well crystallized cubic pyrochlore phase can be obtained at 600 oC, which represents a significant decrease in temperature, if compared with the conventional ceramic synthesis method. The mechanically activated powders exhibit a particle size of around 160 nm, which increases with further thermal treatment.
S.M. Zanetti et al., "Bismuth Zinc Niobate (Bi1.5ZnNb1.5O7) Nanopowder Derived from High Energy Mechanical Activation", Advances in Science and Technology, Vol. 45, pp. 315-320, 2006