Synthesis and Characterization of Tungsten-Bronze Structured Nanocrystalline Ba5SmTi3Nb7O30 Ferroelectric Ceramics by High-Energy Ball Milling

Abstract

In the present work, nanocrystalline tungsten–bronze-structured Ba5SmTi3Nb7O30 ferroelectric ceramic was prepared by a mechanical activation process using high-energy planetary ball mill followed by sintering. The powders milled for different times (5, 10, and 20 h) were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. Detailed studies of dielectric and electrical properties of the compound as a function of temperature and frequency show that dielectric constant increases whereas dielectric loss, Curie temperature (Tc), and conductivity decrease with an increase in milling time. These have been viewed in terms of the decrease in the crystallite size with an increase in the milling time. The ferroelectric, piezoelectric, and pyroelectric behavior of the compound prepared by this technique for 20 h milling is reported.