Crystalline structures, Raman, and Microwave dielectric properties of temperature stability Magnesium Niobate ceramics prepared by nanopowders

Herein, the influence of Cu2+ substitution on the phase composition, bulk density, microstructures, and microwave dielectric properties of Li2CuxZn1−xSiO4 (0 ≤ x ≤ 0.06) ceramics prepared by a solid-state reaction were investigated. The results of XRD and mapping showed that Cu2+ substitution can avoid the influence of secondary phase on the properties of samples. According to the analysis of bulk density, microstructure and microwave dielectric properties, a proper amount of Cu substitution not only improved the sintering characteristics of Li2CuxZn1−xSiO4 ceramics, reduced the densification temperature from 1250 °C to 950 °C, but also increased the Q×f value. Furthermore, Cu2+ substitution also improved the temperature stability of the samples. Particularly, the Li2Cu0.04Zn0.96SiO4 ceramics sintered at 950 °C for 5 h possessed excellent microwave dielectric properties: εr = 5.624, Q×f = 12,764 GHz, and τf = −77 ppm/°C, exhibiting a potential for the low temperature co-fired ceramic applications.

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Effect of small amount of cobalt substitution on structure and microwave dielectric properties of barium magnesium niobate ceramics

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2012.03.025 ◽

2012 ◽

Vol 32 (10) ◽

pp. 2373-2380 ◽

Cited By ~ 6

Author(s):

Ching-Tien Chen ◽

Chi-Yuen Huang ◽

Hong-Jin Lin ◽

Chun-Te Lee

Keyword(s):

Dielectric Properties ◽

Microwave Dielectric Properties ◽

Magnesium Niobate ◽

Microwave Dielectric ◽

Cobalt Substitution

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Materials Design with Enhanced Temperature Stability of Resonant Frequency for High Frequency Application

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.173 ◽

2007 ◽

Vol 124-126 ◽

pp. 173-176 ◽

Cited By ~ 1

Author(s):

Dong Wan Kim ◽

Kug Sun Hong

Keyword(s):

Rare Earth ◽

Dielectric Properties ◽

Resonant Frequency ◽

Microwave Dielectric Properties ◽

Temperature Stability ◽

Dielectric Materials ◽

Low Loss ◽

Microwave Dielectric ◽

End Members ◽

Empirical Approaches

For low temperature cofired ceramic (LTCC) materials to achieve increase functionality, as well as low loss and moderate dielectric constant, it is essential to achieve the temperature stability of the resonant frequency. Facing several empirical approaches toward tuning the temperature coefficient of the resonant frequency (τf) through the formation of mixtures or a solid-solution between the two end members with opposite signs of τf, which result in higher dielectric loss, we took a closer look at the texture engineering that determines the anisotropic dielectric properties in barium niobate ceramics. We demonstrate the advantage of texture engineering for microwave dielectric properties including temperature stability by control of crystallographic orientation. Also, the monoclinic rare earth niobates are investigated as novel microwave dielectric materials. Furthermore, the stable τf of the rare earth niobates could be efficiently explained through the ferroelastic domain engineering related to phase transformation.

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