Fabrication and characterization of crystalline cubic bismuth zinc niobate pyrochlore (Bi_1.5ZnNb_1.5O₇) nanoparticles derived by sol-gel

Abstract

Here, we report the fabrication and characterization of crystalline cubic bismuth zinc niobate pyrochlore, Bi_1.5ZnNb_1.5O₇, (BZN) nanoparticles. A novel sol-gel method is used for the synthesis of air-stable and precipitate-free diol-based sols of BZN which was dried at 150°C and partially calcined at 350 ° C/1 h to decompose organics and bring down the free energy barrier for crystallization. Annealed at 450-700 ° C/1 h, BZN powder exhibited nanocrystalline morphology. The average BZN nanoparticle size were about 6, 60 and 85 nm for the samples annealed at 450, 600 and 700 ° C/1 h, respectively as observed by transmission electron microscope (TEM). The crystallinity and phase formation of the as synthesized nanoparticles were confirmed by the selected-area electron diffraction (SAED), X-ray diffraction (XRD) and high resolution TEM (HRTEM) analysis. Energy-dispersive X-ray spectroscopy (EDX) analysis demonstrated that stoichiometric Bi_1.5ZnNb_1.5O₇ was formed.