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A Novel Low‐Firing and Low Loss Microwave Dielectric Ceramic Li 2 Mg 2 W 2 O 9 with Corundum Structure
Author(s) -
Guo Huanhuan,
Fang Liang,
Jiang Xuewen,
Li Jie,
Lu Fengqi,
Li Chunchun
Publication year - 2015
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.13829
Subject(s) - materials science , corundum , ceramic , temperature coefficient , sintering , rietveld refinement , dielectric , microwave , analytical chemistry (journal) , permittivity , mineralogy , crystal structure , dielectric loss , crystal (programming language) , metallurgy , crystallography , composite material , chemistry , optoelectronics , physics , chromatography , quantum mechanics , computer science , programming language
The crystal structure and microwave dielectric properties of a novel low‐firing compound Li 2 Mg 2 W 2 O 9 were investigated in this study. The phase purity and crystal structure were investigated using X‐ray diffraction analyses and Rietveld refinement. The best microwave dielectric properties of the ceramic with a low permittivity (ε r ) ~11.5, a quality factor ( Q × f) ~31 900 GHz (at 10.76 GHz) and a temperature coefficient of the resonant frequency (τ f ) ~ −66.0 ppm/°C were obtained at the optimum sintering temperature (920°C). CaTiO 3 was added into the Li 2 Mg 2 W 2 O 9 ceramic to obtain a near zero τ f , and 0.93Li 2 Mg 2 W 2 O 9 –0.07CaTiO 3 ceramic exhibited improved microwave dielectric properties with a near‐zero τ f ~ −1.3 ppm/°C, a ε r ~ 21.6, a high Q u × f value ~20 657 GHz. The low sintering temperature and favorable microwave dielectric properties make it a promising candidate for LTCC applications.