Effect of A-site cation on crystal structure and microwave dielectric properties of AGe4O9 (A = Ba, Sr) ceramics

Ca1-x(Li1/2Sm1/2)xTiO3 microwave dielectric ceramics in the x range of 0.70 ~ 0.80 were prepared by conventional ceramics fabrication technique. The crystal structure, microstructure and microwave dielectric properties were investigated. The results showed that a single orthorhombic perovskite structure formed within this x range, and the substitution of (Li1/2Sm1/2)2+ ion for Ca2+ ion in A-site has a significant influence on the microwave dielectric properties of the ceramics. With the increase of substitution of (Li1/2Sm1/2)2+ ion with 0.75, the temperature coefficient of resonant frequency τf reaches zero, and it could be attributed that the Sm and Li have a polarizability effect according to its microstructure. The Ca0.25(Li1/2Sm1/2)0.75TiO3 ceramic had a good performance with microwave dielectric properties of τf = 0 ppm/°C, εr = 105.83, and Qf = 3170 GHz.

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Crystal Structure and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.05]O3-δ Ceramics with Pr3+ Substitution at A-Site

Materials Science and Engineering ◽

10.1142/9789813226517_0142 ◽

2017 ◽

Author(s):

Gang Xiong ◽

Han-Fen Zhang

Keyword(s):

Crystal Structure ◽

Dielectric Properties ◽

Microwave Dielectric Properties ◽

Microwave Dielectric ◽

A Site

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Crystal Structure and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Pr3+ Substitution at A-Site

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.181-182.439 ◽

2011 ◽

Vol 181-182 ◽

pp. 439-442

Author(s):

Gang Xiong

Keyword(s):

Crystal Structure ◽

Dielectric Properties ◽

Quality Factor ◽

Perovskite Structure ◽

Single Phase ◽

Microwave Dielectric Properties ◽

Microwave Dielectric ◽

Resonator Frequency ◽

Orthorhombic Perovskite ◽

A Site

Crystal structure and microwave dielectric properties of (Ca1-xPrx) [(Li1/3Nb2/3)0.95Zr0.15]3+δ (0.0≤x≤0.2, CPLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Pr3+ content, the quality factor value firstly increased, and then began to decrease at x=0.06 due to a decrease of the degree of B-site 1:2 ordering. The variation of τf with tolerance factor was discussed. When x=0.06, the optimum microwave dielectric properties: the permittivity is 33.2, the quality factor is 17120 GHz，and the temperature coefficient of resonator frequency is −5.7×10−6/°C.

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Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Sm3+ Substitution at A-Site

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.698 ◽

2010 ◽

Vol 663-665 ◽

pp. 698-701

Author(s):

Gang Xiong

Keyword(s):

Crystal Structure ◽

Dielectric Properties ◽

Quality Factor ◽

Perovskite Structure ◽

Single Phase ◽

Microwave Dielectric Properties ◽

Microwave Dielectric ◽

Resonator Frequency ◽

Orthorhombic Perovskite ◽

A Site

Crystal structure and microwave dielectric properties of (Ca1-xSmx) [(Li1/3Nb2/3)0.95Zr0.15]3+δ(0.0≤x≤0.2,CSLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Sm3+ content, the quality factor value firstly increased, and then began to decrease at x=0.03 due to a decrease of the degree of B-site 1:2 ordering. The variation of τf with tolerance factor was discussed. When x=0.05, the optimum microwave dielectric properties: the permittivity is 32.4，the quality factor is 16560GHz，and the temperature coefficient of resonator frequency is −6.3×10−6/°C。

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