Ba8ZnTa6O24: A New High Q Dielectric Perovskite
Abstract:The hexagonal perovskite, Ba8ZnTa6O24, was prepared in single-phase form and was found to be a stable secondary phase, formed as a result of the loss of ZnO from Ba(Zn1/3Ta2/3)O3 microwave dielectrics. The experimental and calculated X-ray patterns of Ba8ZnTa6O24 indicate it is isostructural with Ba8Ta6NiO24 with an 8H (cchc)2 close-packed BaO3 stacking sequence and the lattice parameters, a=10.0825(14), c=19.0587(38)Å. High-density ceramics of Ba8ZnTa6O24 could be prepared at temperatures considerably lower (1400°C) than those used to sinter pure Ba(Zn1/3Ta2/3)O3, and exhibit very good microwave dielectric properties with =30.5, Qf=62 300, and f=+36 ppm/°C at 8.9 GHz.
Document Type: Research Article
Affiliations: Department of Materials Science & Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6272
Publication date: 2005-08-01