Ba₄LiNb_3−xTa_xO₁₂ (x=0–3): A Series of High‐Q Microwave Dielectrics from the Twinned 8H Hexagonal Perovskites

Abstract

A series of the twinned 8H hexagonal perovskites in the Ba 4 LiNb 3Àx Ta x O 12 (x 5 0-3) system were synthesized by the conventional solid-state reaction method. Ba 4 LiNb 3Àx Ta x O 12 solid solutions were single phase in the whole range of x values. The ceramics exhibit perfect microwave dielectric properties with relative permittivity, e r B28-37, high quality factor, Q Â fB37 000-104 000 GHz, and temperature coefficient of resonant frequency, s f B125-165 ppm/1C.

Effects of BaCu(B2O5) Addition on Phase Transition, Sintering Temperature, and Microwave Properties of Ba4LiNb3O12 Ceramics

“…The variations of t f values of BCB added ceramics sintered at 9501C are summarized in Table I. 14 The temperature coefficient of resonant frequency significantly decreases from 65 to 11.8 ppm/1C, and this can be explained by the logarithmic mixture law for complex dielectrics. It is reported that the t f value can be tuned by the formation of solid solution or mixtures of dielectrics with opposite t f values.…”

BaTa2V2O11: A novel low fired microwave dielectric ceramic

“…5, Q × f value of 62,300 GHz, and τ f value of 36 ppm/ • C [11]. The Ba 4 LiNb 3−x Ta x O 12 (x = 0-3) ceramics were reported to exhibit perfect microwave dielectric properties with ε r ∼28-37, Q × f ∼37,000-104,000 GHz, and τ f ∼25-65 ppm/ • C [12]. Ba(Zn 1/3 Ta 2/3 )O 3 ceramics sintered at 1450 • C obtained excellent dielectric properties with ε r ∼30, Q × f ∼70,000 GHz, and τ f ∼10 ppm/ • C [15].…”

“…Up to now, numerous Ta-based compounds with excellent microwave dielectric properties have been reported [10][11][12][13][14]. For example, Ba 8 ZnTa 6 O 24 ceramics have been proved to be an excellent dielectric material with ε r of 30.…”

A Novel Low‐Firing and Low Loss Microwave Dielectric Ceramic Li2Mg2W2O9 with Corundum Structure

“…The traditional microwave dielectric ceramics, although have high performance and have been widely used in practice, usually have high sintering temperatures, such as Ba 8 MgTa 6 O 24 (1600°C), 6 Ba(Zn 1/3 Ta 2/3 )O 3 (1450°C), 7 Ba (Mg 1/3 Ta 2/3 )O 3 (1600°C), 8 Ba 8 ZnTa 6 O 24 (1400°C). 9 To lower their sintering temperature, several methods have been proposed including reducing the particle sizes, chemical synthesis methods and addition of low-temperature sintering aids, such as Li 2 CO 3 , BaCu(B 2 O 5 ), V 2 O 5 , etc. [10][11][12] Among them, addition of sintering aids is the most popular method to lower the sintering temperature.…”