A novel process to synthesize high-k 'Y5V' nanopowder and ceramics

The present work proposes a simple one-step sol gel process for the synthesis of high-k (Ba0.87Sr0.04Ca0.09)(Ti0.86Zr0.08Sn0.06)O-3 (BSCTZS) powders and ceramics. Characterization using TG-DTG, XRD, SEM and TEM methods reveals that the powders are of nanometer scale and exhibit a cubic perovskite structure. After sintering, cubic BaTiO3 structure ceramics were obtained. Compared to the traditional method of preparation, the powders and ceramics prepared by the one-step sol-gel process exhibit a high dielectric constant due to narrow grain size distribution, controlled morphology, and high purity. Doped niobium decreases the grain size of BSCTZS ceramics and lowers the Curie temperature. At a Nb concentration of 0.38 mol%, BSCTZS ceramics meet the EIA Y5V specifications and the room temperature (25 degrees C) permittivity is greater than 16,000. The BSCTZS nanopowders prepared through the process with uniformity component will increase the volumetric efficiency of multi-layer ceramic capacitors by decreasing the dielectric layer thickness. Most importantly, this new approach greatly simplifies the preparation processes. Crown Copyright (C) 2011 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.