Order–disorder behaviour in 0.9Ba([Zn0.60Co0.40]1/3Nb2/3)O3–0.1Ba(Ga0.5Ta0.5)O3 microwave dielectric resonators

Temperature‐stable, medium‐permittivity dielectric ceramics have been used as resonators in filters for microwave (MW) communications for several decades. The growth of the mobile phone market in the 1990s led to extensive research and development in this area. The main driving forces were the greater utilization of available bandwidth, that necessitates extremely low dielectric loss (high‐quality factor), an increase in permittivity so that smaller components could be fabricated, and, as ever in the commercial world, cost reduction. Over the last decade, a clear picture has emerged of the principal factors, that influence MW properties. This article reviews these basic principles and gives examples of where they have been used to control microwave properties and ultimately develop new materials.

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“…Therefore, Hughes et al 34 . and Reaney et al 35 . prepared a solid solution of BGT rather than SGT with BCZN.…”

Section: Discussionmentioning

confidence: 99%

“…Many of these simple empirical principles were used to guide the development of 0.9Ba(Co 0.6 Zn 0.4 )NbO 3 –0.1BaGa 1/2 Ta 1/2 O 3 (BCZN–BGT) ceramics, that have zero τ f , ɛ r =34, and Q × f 0 >90 000 34,35 . BZN, the base compound in the BCZN–BGT solid solution, has τ f =+20 MK −1 , Q × f 0 =60 000 with ɛ r =40 34 .…”

Section: Discussionmentioning

confidence: 99%

Microwave Dielectric Ceramics for Resonators and Filters in Mobile Phone Networks

Reaney

Iddles

2006

Journal of the American Ceramic Society

1,074

642

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“…12,15,16 However, such perovskites, although combined with high quality factor, usually feature negative temperature coefficient, [6][7][8][9][10][11][12]19 which has precluded their usage in practice. Targeting at compensating their f values, an effective method has been developed to combine two or more compounds with negative and positive temperature coefficients, respectively, to form solid solutions or mixed phases, [20][21][22][23][24][25][26][27][28] such as Ca͑Al 0.5 Nb 0.5 ͒O 3 -CaTiO 3 , 26 Ca͑Mg 1/3 Nb 2/3 ͒O 3 -SrTiO 3 , 27 and La͑Mg 1/2 Ti 1/2 ͒O 3 -BaTiO 3 28 complex perovskites. Results exhibited that zero f values could be obtained at the proper composition ratio between the end members.…”

Section: Introductionmentioning

confidence: 99%

Crystal structure and dielectric properties of (1−x)Ca0.61Nd0.26TiO3+xNd(Mg1/2Ti1/2)O3 complex perovskite at microwave frequencies

Chu

et al. 2008

Journal of Applied Physics

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The crystal structure and microwave dielectric properties of (1−x)Ca0.61Nd0.26TiO3+xNd(Mg1/2Ti1/2)O3 (0≤x≤1.0) solid solutions incorporated with 1 wt % CuO were investigated. Pure perovskite phases were formed in the whole composition range, and the crystal space group and unit cell volume of the perovskites were analyzed based on x-ray diffraction patterns. The configuration of octahedral tilting and the B-site ordering phase transition between x=0.9 and 1.0 were unambiguously assigned, respectively, to the corresponding superlattice diffractions. Moreover, the two important fingerprints A1g mode and F2g mode in Raman spectra, associated with the evolution of short range ordering and long range ordering of B-site cations, respectively, were further investigated by employing the full width at half-maximum and their Raman shifts to determine the degree of B-site ordering and the crystal bond strength in the perovskites. The microwave dielectric constants, quality factors, and temperature coefficients of resonant frequency of the solid solutions were elaborately investigated and correlated with their crystal structures. The microscopic structure-related thermal parameters in the solid solution were calculated using the Claussius–Mossotti equation to determine the original contributors in the temperature coefficients. Temperature compensated τf value ceramics could be obtained in the range of 0.3<x<0.5. When sintered at 1400 °C for 2.5 h, a dielectric constant εr of 39.9, a quality factor product of 12 600 GHz, and a τf of −25.3 ppm/°C microwave dielectric ceramic were obtained in 0.5Ca0.61Nd0.26TiO3+0.5Nd(Mg1/2Ti1/2)O3+1 wt % CuO composition.

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“…A lot of works are related to the complex perovskites with good dielectric properties, just like substitutions at A and B sites, ordering, doping, glass addition, annealing, non-stoichiometry and so on [6][7][8][9][10]. It is worth mentioning that the high Q value is related to the 1:2 type of cation ordering in the B site [11,12]. The high ordering degree can be obtained in the Ba(Zn 1/3 Ta 2/3 )O 3 ceramics by prolonging the sintering time [13].…”

Section: Introductionmentioning

confidence: 99%

Low loss (Ba1−xSrx)(Co1/3Nb2/3)O3 solid solution: phase evolution, microstructure and microwave dielectric properties

Wang

Huang

Wang

et al. 2015

J Mater Sci: Mater Electron

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Ba 1-x Sr x )(Co 1/3 Nb 2/3 )O 3 (0 B x B 0.5) microwave dielectric ceramics had been prepared using the solid-state reaction method. The dense microstructures with small grains were obtained. All Sr 2? substituted samples exhibited the perovskite phase. The structure transition from cubic to hexagonal occurred with the increase of x, which led to higher degree of 1:2 ordered structure in the B site. The improved Q 9 f value was correlated monotonously with the ordering parameters S. The dielectric constant (e r ) and the temperature coefficient of resonant frequency (s f ) could be effectively tuned by tailoring x. A good combination of microwave dielectric properties was obtained for (Ba 0.95 Sr 0.05 )(Co 1/3 Nb 2/3 )O 3 sintered at 1380°C: e r = 33.3, Q 9 f = 87,120 GHz, s f = 4 ppm/°C.

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Order–disorder behaviour in 0.9Ba([Zn0.60Co0.40]1/3Nb2/3)O3–0.1Ba(Ga0.5Ta0.5)O3 microwave dielectric resonators

Cited by 28 publications

References 18 publications

Microwave Dielectric Ceramics for Resonators and Filters in Mobile Phone Networks

Microwave Dielectric Ceramics for Resonators and Filters in Mobile Phone Networks

Crystal structure and dielectric properties of (1−x)Ca0.61Nd0.26TiO3+xNd(Mg1/2Ti1/2)O3 complex perovskite at microwave frequencies

Low loss (Ba1−xSrx)(Co1/3Nb2/3)O3 solid solution: phase evolution, microstructure and microwave dielectric properties

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