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Ba 8 ZnTa 6 O 24 : A New High Q Dielectric Perovskite
Author(s) -
Thirumal M.,
Davies P. K.
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00426.x
Subject(s) - isostructural , dielectric , perovskite (structure) , materials science , mineralogy , analytical chemistry (journal) , hexagonal crystal system , non blocking i/o , crystallography , dielectric loss , crystal structure , chemistry , biochemistry , optoelectronics , chromatography , catalysis
The hexagonal perovskite, Ba 8 ZnTa 6 O 24 , 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(Zn 1/3 Ta 2/3 )O 3 microwave dielectrics. The experimental and calculated X‐ray patterns of Ba 8 ZnTa 6 O 24 indicate it is isostructural with Ba 8 Ta 6 NiO 24 with an 8H (cchc) 2 close‐packed BaO 3 stacking sequence and the lattice parameters, a =10.0825(14), c =19.0587(38)Å. High‐density ceramics of Ba 8 ZnTa 6 O 24 could be prepared at temperatures considerably lower (1400°C) than those used to sinter pure Ba(Zn 1/3 Ta 2/3 )O 3 , and exhibit very good microwave dielectric properties with ɛ=30.5, Q f =62 300, and τ f =+36 ppm/°C at 8.9 GHz.