Sol-Gel Synthesis and Characterization of Cubic Bismuth Zinc Niobium Oxide Nanopowders

Abstract EN

Bismuth zinc niobium oxide (BZN) was successfully synthesized by a diol-based sol-gel reaction utilizing metal acetate and alkoxide precursors.

Thermal analysis of a liquid suspension of precursors suggests that the majority of organic precursors decompose at temperatures up to 150°C, and organic free powders form above 350°C.

The experimental results indicate that a homogeneous gel is obtained at about 200°C and then converts to a mixture of intermediate oxides at 350–400°C.

Finally, single-phased BZN powders are obtained between 500 and 900°C.

The degree of chemical homogeneity as determined by X-ray diffraction and EDS mapping is consistent throughout the samples.

Elemental analysis indicates that the atomic ratio of metals closely matches a Bi1.5ZnNb1.5O7 composition.

Crystallite sizes of the BZN powders calculated from the Scherrer equation are about 33–98 nm for the samples prepared at 500–700°C, respectively.

The particle and crystallite sizes increase with increased sintering temperature.

The estimated band gap of the BZN nanopowders from optical analysis is about 2.60–2.75 eV at 500-600°C.

The observed phase formations and measured results in this study were compared with those of previous reports.