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

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。

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

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.

Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Ba2+ Substitution at A-Site

2007 ◽  
Vol 336-338 ◽  
pp. 196-198
Author(s):  
Dong Xiang Zhou ◽  
G. Xiong ◽  
Shu Ping Gong ◽  
Jun Zhao ◽  
M.Z. Hu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Bond Valence ◽  
Microwave Properties ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite ◽  
A Site

The microwave properties of (Ca1-xBax)[(Li1/3Nb2/3)0.95Zr0.15]O3+δ(0.0≤x≤0.2, CBLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x = 0.0 − 0.025. Both the εr and Qf value firstly increased with increasing Ba2+ content, and then began to decrease at x = 0.025. The τf value increased from −9.4 ppm/°C at x=0.0 to 18ppm/°C at x=0.2, which could be explained by the decrease of B-site bond valence in perovskite structure.

Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.05]O3−δ−xTiO2 Ceramics

2011 ◽  
Vol 181-182 ◽  
pp. 405-408
Author(s):  
Gang Xiong
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

Crystal structure and microwave dielectric properties of Ca [(Li1/3Nb2/3) 0.95Zr0.05]O3−δ−xTiO2(0≤x≤0.1) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.02~0.1. With an increasing of Ti4+ content, the Qf value decreased due to a decrease of the degree of B-site 1:2 ordering. However, the τf value increased from-14.7ppm /°C to-6.9ppm/°C. When x=0.04, the optimum microwave dielectric properties: εr=31.1, Qf =21640GHz and τf =−8.8 ppm/°C.

Crystal Structure and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3) 0.92Zr0.08]O3-δ−xTiO2 Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 515-518
Author(s):  
Gang Xiong
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Negative Direction ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

Crystal structure and microwave dielectric properties of Ca[(Li1/3Nb2/3) 0.92Zr0.08]O3−δ−xTiO2(0≤x≤0.2) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.1. With an increasing of Ti4+ content, the Qf value decreased due to a decrease of the degree of B-site 1:2 ordering. However, the τf value firstly increased from-14.2ppm /°C to -6.6ppm/°C, and then moved to the negative direction. When x=0.05, the optimum microwave dielectric properties: εr=32.8, Qf =19460GHz and τf =−8.3 ppm/°C.

Microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti) ceramics

1999 ◽  
Vol 14 (9) ◽  
pp. 3567-3570 ◽  
Author(s):  
Ji-Won Choi ◽  
Chong-Yun Kang ◽  
Seok-Jin Yoon ◽  
Hyun-Jai Kim ◽  
Hyung-Jin Jung ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Multiphase Materials ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

The microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti, 0 ≤ x ≤ 0.5) ceramics were investigated. In general, the ceramics prepared were multiphase materials. However, single-phase specimens having orthorhombic perovskite structure similar to CaTiO3 could be obtained in the vicinity of Sn = 0.2 to 0.3, and Ti = 0.2. As Sn concentration increased, the dielectric constant (εr) decreased and the quality factor (Q) significantly increased within the limited Sn concentration. As Ti concentration increased, the dielectric constant (εr) increased, the quality factor (Q) decreased, and the temperature coefficient of resonant frequency (τf) changed from a negative to positive value. The temperature coefficient of resonant frequency of 0 ppm/°C was realized at Ti = 0.2. The Q · fo value and εr for this composition were found to be 26100 GHz and 38.6, respectively.

Microwave Dielectric Properties of Ca1-x(Li1/2Sm1/2)xTiO3 Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 238-241 ◽  
Author(s):  
Yue Ming Li ◽  
Ting Ting Song ◽  
Fei Hu ◽  
Run Hua Liao ◽  
Bin Zhang
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Fabrication Technique ◽  
Microwave Dielectric ◽  
Polarizability Effect ◽  
Orthorhombic Perovskite ◽  
Dielectric Ceramics ◽  
A Site

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.

Sintering Behavior and Microwave Dielectric Properties of Li2O-B2O3-SiO2 Doped 0.67CaTiO3-0.33LaAlO3 Ceramics

2017 ◽  
Vol 726 ◽  
pp. 220-224
Author(s):  
Gan Wang ◽  
Juan Jiang ◽  
Zhan Ming Dou ◽  
Fan Fan Ning ◽  
Er Tian Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Amorphous State ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Low Temperature Sintering ◽  
Microwave Dielectric ◽  
Structure Surface ◽  
Sintering Method

A low temperature sintering method was used to avoid the relatively high sintering temperatures typically required to prepare 0.67CaTiO3-0.33LaAlO3 (CTLA) ceramics. 0.67CaTiO3-0.33LaAlO3 ceramics doped with Li2O-B2O3-SiO2 (LBS) were prepared by a conventional two-step solid-state reaction process. The sintering behavior, crystal structure, surface morphology, and microwave dielectric proprieties of the prepared ceramics were studied. As the small amount of LBS content increased, the small amount of liquid phase formed in an amorphous state around the surface of the grain boundaries. With the increase the content of LBS glass, the quality factor (Q×f) value decreased. CTLA+0.05 wt.% LBS ceramics sintered at 1320°C for 4h exhibited the optimal microwave dielectric properties of dielectric permittivity (εr) = 45.02, quality factor (Q×f) = 37400 GHz, and temperature coefficient of resonant frequency (τf) = 9.84 ppm/°C. .

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