Lattice vibrational characteristics, crystal structure, and dielectric properties of single-phase Sr(Mg1/2Mo1/2)O3 microwave dielectric ceramic

2021 ◽  
Author(s):  
Wenhao Yu ◽  
Jiqing Lv ◽  
Feng Shi ◽  
Kaixin Song ◽  
Wen Lei ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Single Phase ◽  
Microwave Dielectric Ceramic ◽  
Dielectric Ceramic ◽  
Microwave Dielectric ◽  
Vibrational Characteristics

Temperature compensation effects of TiO2 on Ca[(Li1/3Nb2/3)0.8Sn0.2]O3−δ microwave dielectric ceramic

2017 ◽  
Vol 31 (27) ◽  
pp. 1750192
Author(s):  
Mingzhe Hu ◽  
Huanghe Wei ◽  
Lihua Xiao ◽  
Kesheng Zhang ◽  
Yongde Hao
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramic ◽  
Microwave Ceramics ◽  
Dielectric Ceramic ◽  
Structure Transition ◽  
Microwave Dielectric ◽  
Dielectric Devices

The crystal structure and dielectric properties of TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] microwave ceramics are investigated in the present paper. The crystal structure is probed by XRD patterns and their Rietveld refinement, results show that a single perovskite phase is formed in TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramics with the crystal structure belonging to the orthorhombic Pbnm 62 space group. Raman spectra results indicate that the [Formula: see text]-site order–disorder structure transition is a key point to the dielectric loss of TiO2-modified Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramics at microwave frequencies. After properly modified by TiO2, the large negative temperature coefficient of Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Sn[Formula: see text]]O[Formula: see text] ceramic can be compensated and the optimal microwave dielectric properties can reach [Formula: see text] = 25.66, [Formula: see text] = 18,894 GHz and TCF = −6.3 ppm/[Formula: see text]C when sintered at 1170[Formula: see text]C for 2.5 h, which manifests itself for potential use in microwave dielectric devices for modern wireless communication.

A Novel Microwave Dielectric Ceramic Ca2Zn4Ti16O38: Preparation and Dielectric Properties.

ChemInform ◽  
2006 ◽  
Vol 37 (38) ◽  
Author(s):  
Fei Zhao ◽  
Zhenxing Yue ◽  
Jing Pei ◽  
Zhilun Gui ◽  
Longtu Li
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Ceramic ◽  
Dielectric Ceramic ◽  
Microwave Dielectric

Studies on Structural, Microwave Dielectric Properties, and Low-Temperature Sintering of 1.52Li2O-0.36Nb2O5-1.34TiO2 Ceramic

2012 ◽  
Vol 512-515 ◽  
pp. 1226-1230
Author(s):  
Qun Zeng ◽  
Yong Heng Zhou
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramic ◽  
Low Temperature Sintering ◽  
Dielectric Ceramic ◽  
Microwave Dielectric ◽  
M Phase ◽  
Two Phases

The structure, microwave dielectric properties and low-temperature sintering of a new Li2O-Nb2O5-TiO2 system ceramic with the Li2O: Nb2O5: TiO2 mole ratio of 1.52: 0.36: 1.34 have been investigated in this study. The 1.52Li2O-0.36Nb2O5-1.34TiO2 (LNT) ceramic is composed of two phases, the “M-Phase” and Li2TiO3 solid solution (Li2TiO3ss) phase. This new microwave dielectric ceramic has low intrinsic sintering temperature ( ~ 1100 oC ) and good microwave dielectric properties of middle permittivity (εr ~38.6), high Q×f value up to 7712 GHz, and near zero τf value (~ 4.64 ppm/oC). In addition, the sintering temperature of the LNT ceramics could be lowered down effectively from 1100 oC to 900 oC by adding 1 wt.% B2O3. Good microwave dielectric properties of εr = 42.5, Q*f =6819 GHz and τf = 2.7 ppm/oC could be obtained at 900 oC, which indicate the ceramics would be promising candidates for low-temperature co-fired ceramics (LTCC) applications.

A new low-loss microwave dielectric ceramic for low temperature cofired ceramic applications

2010 ◽  
Vol 25 (7) ◽  
pp. 1235-1238 ◽  
Author(s):  
Huanfu Zhou ◽  
Xiuli Chen ◽  
Liang Fang ◽  
Dongjin Chu ◽  
Hong Wang
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramic ◽  
X Ray Diffraction ◽  
Low Loss ◽  
Dielectric Ceramic ◽  
X Ray ◽  
Microwave Dielectric

A new low sintering temperature microwave dielectric ceramic, Li2ZnTi3O8, was investigated. X-ray diffraction data show that Li2ZnTi3O8 has a cubic structure [P4332(212)] with lattice parameters a = 8.37506 Å, V = 587.44 Å3, and Z = 4 when the sintering temperature is 1050 °C. The Li2ZnTi3O8 ceramic exhibits good microwave dielectric properties with εr about 26.2, Q×f value about 62,000 GHz, and τf about −15 ppm/°C. The addition of BaCu(B2O5) can effectively lower the sintering temperature from 1050 to 900 °C without degrading the microwave dielectric properties. Compatibility with Ag electrode indicates this material can be applied to low temperature cofired ceramic devices.

Preparation and Study of (1-m)(Mg0.8Zn0.2)TiO3·m{Ba4Nd28/3Ti18O54·0.18Bi2O3} Microwave Dielectric Ceramics

2014 ◽  
Vol 616 ◽  
pp. 166-173
Author(s):  
Xiao Li Ji ◽  
Peng Fei Hu ◽  
Song Zhang ◽  
Cheng C. Zhai ◽  
Fang Yi
Keyword(s):  
Dielectric Properties ◽  
Composite System ◽  
Sintering Temperature ◽  
Microwave Dielectric Ceramic ◽  
Microwave Dielectric Ceramics ◽  
Structure And Properties ◽  
Dielectric Ceramic ◽  
Two Phase ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

In this work, the microwave dielectric ceramic (1-m)(Mg0.8Zn0.2)TiO3·m{Ba4Nd28/3Ti18O54·0.18Bi2O3}(m=0.1~0.4)(MZT-BNT) was studied to improve dielectric properties. The results of the dielectric properties, density, XRD and SEM show that the value of m and the sintering temperature affected the structure and properties of the ceramics. MZT-BNT composite system is a two-phase composite system. With the adding of BNT, the dielectric properties of MZT increase significantly. As m value increases, the bulk density and the dielectric constant of the composite system increase, while the quality factor reduces and the temperature coefficient of resonant frequency is close to zero. The dielectric properties of MZT-BNT sintered at 1200 °C (m = 0.3) are εr = 34.03, Qf = 7177 GHz,τf = -3.39 ppm/°C, respectively.

scholarly journals Additive Manufacturing of Monolithic Microwave Dielectric Ceramic Filters via Digital Light Processing

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1067 ◽  
Author(s):  
Liu ◽  
Qiu ◽  
Shen ◽  
Jiao ◽  
Ye ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Dielectric Properties ◽  
Molar Ratio ◽  
Microwave Dielectric Ceramic ◽  
Dielectric Ceramic ◽  
Digital Light Processing ◽  
Ceramic Filters ◽  
Microwave Dielectric ◽  
Different Temperatures ◽  
The Difference

Microwave dielectric ceramics are employed in filters as electromagnetic wave propagation media. Based on additive manufacturing (AM) techniques, microwave dielectric ceramic filters with complex and precise structures can be fabricated to satisfy filtering requirements. Digital light processing (DLP) is a promising AM technique that is capable of producing filters with high accuracy and efficiency. In this paper, monolithic filters made from Al2O3 and TiO2, with a molar ratio of9:1 (0.9 Al2O3-0.1 TiO2), were fabricated by DLP. The difference in the dielectric properties between the as-sintered and post-annealed samples at different temperatures was studied. The experimental results showed that when sintered at 1550 °C for 2 h and post annealed at 1000 °C for 5 h, 0.9 Al2O3-0.1 TiO2 exhibited excellent dielectric properties: εr = 12.4, Q × f = 111,000 GHz, τf = + 1.2 ppm/°C. After comparing the measured results with the simulated ones in the passband from 6.5 to 9 GHz, it was concluded that the insertion loss (IL) and return loss (RL) of the filter meet the design requirements.

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 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。

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