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Effects of Nb 2 O 5 Doping on the Microwave Dielectric Properties and Microstructures of Bi 2 Mo 2 O 9 Ceramics
Author(s) -
Lee YingChieh,
Chiu JamDa,
Chen Yu Hong
Publication year - 2013
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/jace.12204
Subject(s) - materials science , sintering , ceramic , dielectric , analytical chemistry (journal) , dopant , microstructure , doping , dielectric loss , permittivity , mineralogy , phase (matter) , microwave , metallurgy , chemistry , optoelectronics , organic chemistry , physics , chromatography , quantum mechanics
This study investigated the effects of the addition of Nb 2 O 5 and sintering temperature on the properties of Bi 2 Mo 2 O 9 ceramics. The ceramics were sintered in air at temperatures ranging from 620°C to 680°C. The addition of small amounts of Nb 2 O 5 as a dopant significantly affected the crystalline phase and the microwave dielectric properties of the Bi 2 Mo 2 O 9 ceramics. The secondary phase, γ‐ Bi 2 MoO 6 , was observed when Nb 2 O 5 was added. However, unlike the Bi 2 Mo 2 O 9 ceramic without Nb 2 O 5 sintered above 645°C, the ceramics with 3 mol% Nb 2 O 5 contained no γ‐ Bi 2 MoO 6 when sintered at 660°C. The Q × f value and τ f of the Bi 2 Mo 2 O 9 ceramics were improved by Nb 2 O 5 doping. The Bi 2 Mo 2 O 9 ceramics doped with 2 mol% Nb 2 O 5 exhibited the best microwave dielectric properties, with a permittivity of 36.5, a Q × f value ( f = resonant frequency, Q = 1/dielectric loss at f ) of 14100 GHz and τ f of +5.5 ppm/°C after sintering at 620°C.