scholarly journals L attice V ibrational C haracteristics , Crystal Structure s , and D ielectric P roperties of Li Mn PO 4  Microwave Dielectric Ceramics as a Function of Sintering Temperature

2021 ◽  
Author(s):  
xiangyu wang ◽  
encai xiao ◽  
Lingcui Zhang ◽  
Yue Xu ◽  
tong liu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Packing Fraction ◽  
Raman Shift ◽  
Microwave Dielectric Ceramics ◽  
Structure Property ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

Abstract LiMnPO4 (LMP) microwave dielectric ceramics were manufactured at different temperatures via a standard solid-state reaction method, and the LMP ceramic sintered at 750 °C displayed dielectric properties of εr = 7.82, Q × f = 29,189 (f = 12.7 GHz). The lattice vibrational characteristics of LMP ceramics were studied utilizing both infrared reflection and Raman scattering spectroscopy to clarify the basic principle of the dielectric response. The intrinsic properties that were fitted and simulated based on the infrared spectra agreed with the measured property values. The low-frequency vibrational modes contributed more to the dielectric properties than the high-frequency modes. Upon increasing the temperature, the permittivity was positively correlated with the bond length but showed the opposite trend of the Raman shift of mode 9 Ag(υ1). The Q × f value was positively correlated with the packing fraction but negatively correlated with the FWHM of mode 10 Ag(υ3). Thus, the structure-property relationships of LMP ceramics were established as a function of sintering temperature.

Structure and Microwave Dielectric Properties of (Ca0.9375Sr0.0625)0.25 (Li0.5Sm0.5)0.75TiO3 Ceramics with B2O3-CuO Sintering Aids

2011 ◽  
Vol 284-286 ◽  
pp. 1442-1446
Author(s):  
Yue Ming Li ◽  
Zong Yang Shen ◽  
Zhu Mei Wang ◽  
Hua Zhang ◽  
Yan Hong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Sintering Aids ◽  
Oxide Mixture ◽  
High Permittivity ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The B2O3-CuO oxide mixture (abbreviated as BC) was selected to lower the sintering temperature of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (abbreviated as CSLST) microwave dielectric ceramics by solid sate reaction technique. The effects of BC doping amounts on the crystal structure, microstructure and microwave dielectric properties of the ceramics were investigated. For the ceramic sample with the composition of CSLST + 5 wt% BC, its sintering temperature was reduced to 1000 °C as compared to 1200 °C for pure CSLST. In addition to the obtained good microwave dielectric properties as follows: εr = 80.4, Q×f = 1380 GHz, τf = -32.89 ×10-6/°C, this ceramic was a desirable high-permittivity microwave dielectric candidate for low-temperature cofired ceramic (LTCC) applications.

Low Temperature Sintering of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 Microwave Dielectric Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1028-1031
Author(s):  
Yue Ming Li ◽  
Hua Zhang ◽  
Zhu Mei Wang ◽  
Yan Hong ◽  
Zong Yang Shen
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Low Temperature Sintering ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The sintering behavior and microwave dielectric properties of the (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (CSLST) ceramics doped with different amounts of Li2O-B2O3-SiO2-CaO-Al2O3 (LBSCA) glass were investigated. The sintering temperature of the CSLST ceramics can be effectively reduced over 200oC due to the addition of LBSCA glass. For the 5 wt% LBSCA-doped CSLST ceramics, which are sintered at only 1000 oC for 5 h, show optimum microwave dielectric properties as follows: εr=84.74, Qf=2446 GHz and τf=-12.48 ppm/oC.

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.

Effects of ZnO-Bi2O3-B2O3-SiO2 Glass Additive on Dielectric Properties of CaO-Li2O-Sm2O3-TiO2 Microwave Dielectric Ceramics

2010 ◽  
Vol 148-149 ◽  
pp. 1580-1583
Author(s):  
Liu Shuan Yang ◽  
Xiao Wang ◽  
Jin Liang Huang ◽  
Fei Long Li
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Second Phase ◽  
Microwave Dielectric Ceramics ◽  
Frequency Shifts ◽  
Glass Addition ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The effects of ZnO-Bi2O3-B2O3-SiO2(ZBBS) glass addition on the sintering behavior, crystalline phase, microstructure and dielectric properties of 16CaO-9Li2O-12Sm2O3-63TiO2(CLST) ceramics were investigated. The results show that ZBBS glass can effectively decrease the sintering temperature of CLST ceramics to 1 000 °C by liquid phase sintering. With the increase of ZBBS content, the second phase，Sm2Ti2O7 is found and increase, which causes the dielectric constant and dielectric loss of CLST decrease. The temperature coefficient of the resonance frequency shifts to positive. The optimum dielectric properties of r = 71, Tan = 0.006, TCF= 5×10-6/°C were obtained in 10wt% LBS glass-doped CLST ceramics sintered at 1 000 °C for 3 h.

Effect of H3BO3 Additive and Forming Pressure on Microwave Dielectric Properties of 0.95MgTiO3-0.05CaTiO3

2014 ◽  
Vol 941-944 ◽  
pp. 521-524
Author(s):  
Jin Bao Huang ◽  
Yi Xiang Cai ◽  
Zhao Xian Xiong ◽  
Hao Xue
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Method Effect ◽  
Best Value ◽  
Dielectric Ceramics ◽  
Quality Factor Q

0.95MgTiO3-0.05CaTiO3 (95MCT) microwave dielectric ceramics was prepared solid-state reaction method. Effect of H3BO3 additive and forming pressure on sintering process, microstructure and microwave dielectric properties of 95MCT were investigated. The result showed that the additive of H3BO3 can lower the sintering temperature of 95MCT, and improve the densification of 95MCT. MgTi2O5 was found as mesosphere, which can be effectively suppressed through the additive of H3BO3. Excellent microwave dielectric properties of ceramics was obtained when the H3BO3 additive was 0.50wt%. The best value of dielectric constant (εr), quality factor (Q×f) and temperature coefficient of resonant frequency (τf ) of 21.54, 67,286GHz and-4.1ppm/oC was obtained for the ceramics with sintering 1220oC for 2h.

Effects of Sintering Temperatures on Microwave Properties of Mg4Nb2O9 Ceramics by the Solid-State Process

2012 ◽  
Vol 499 ◽  
pp. 178-182
Author(s):  
Yi Shan Jiang ◽  
Ying Zi Wang ◽  
Ya Ming Chen ◽  
Yun Long Yue ◽  
Hai Tao Wu
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Solid State Method ◽  
Microwave Dielectric ◽  
State Process ◽  
Density Values ◽  
Dielectric Ceramics

Microwave dielectric ceramics of Mg4Nb2O9were prepared by the solid-state method and their microwave dielectric properties and microstructure were investigated in this study. The sintering ability and microwave dielectric properties of Mg4Nb2O9ceramics were studied under various sintering temperatures ranging from 1200°C to 1350°C. As the sintering temperature increased from 1200°C to 1350°C, the density values, the εr values and the Q·ƒ values increased and saturated at 1350°C.The ƒ values were ranged from -48.7 to -57.8 ppm/°C. Due to the increased density and appropriate grain growth the Mg4Nb2O9ceramics sintered at 1350°C had the excellent microwave dielectric properties of εr=12.3, Q·ƒ =108,000GHz and ƒ=-55.3ppm/°C.

Effect of V2O5 and ZnO Additives on the Sintering Temperature and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3) 0.8Ti 0.2]O3-δ Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 77-80 ◽  
Author(s):  
Ji Hong Liao ◽  
Ying Dai ◽  
Ren Zhou Yang ◽  
Wen Chen
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Conventional Solid State Reaction ◽  
Microwave Dielectric ◽  
Diffraction Peaks ◽  
Dielectric Ceramics ◽  
The Relationship

Low-temperature sintered Ca[(Li1/3Nb2/3)0.8Ti0.2]O3-δ (CLNT) microwave dielectric ceramics with V2O5 and ZnO additives were prepared by the conventional solid state reaction method. The sintering behavior and microwave dielectric properties of CLNT ceramics were investigated. The main diffraction peaks of all the specimens sintered at the temperature under 1150◦C split due to the coexistence of the non-stoichiometric phase and stoichiometric phase, which all possess CaTiO3-type perovskite structures. ZnO and V2O5 combined additives lowered the sintering temperature of CLNT ceramics from 1150◦C to 1090◦C. and the Qf values were improved from 18,210 GHz to 20,740 GHz. The CLNT ceramics with 4 wt% ZnO addition sintered at 1090◦C showed good microwave dielectric properties with εr ~39.7, Qf ~20,740 GHz, τf ~8.6 ppm/◦C. The relationship between dielectric properties and the sintering behavior was also discussed.

scholarly journals Structure–property relationships of low sintering temperature scheelite-structured (1 − x)BiVO4–xLaNbO4 microwave dielectric ceramics

2017 ◽  
Vol 5 (10) ◽  
pp. 2695-2701 ◽  
Author(s):  
Li-Xia Pang ◽  
Di Zhou ◽  
Ze-Ming Qi ◽  
Wei-Guo Liu ◽  
Zhen-Xing Yue ◽  
...  
Keyword(s):  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Ceramics ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Microwave Dielectric ◽  
Low Sintering Temperature ◽  
Dielectric Ceramics

A permittivity of ∼76.3 ± 0.5 and a quality factor >10 000 GHz were obtained in 0.94BiVO4–0.06LaNbO4 ceramic sintered at 800 °C.

Structural Evolution and Microwave Dielectric Properties of Ba(Co1/3(Nb1-xW5x/6)2/3)O3 Ceramics

2018 ◽  
Vol 281 ◽  
pp. 585-590
Author(s):  
Zhe Fei Wang ◽  
Chen Yao Zhai ◽  
Xu Hong Wang
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Structural Evolution ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

Ba(Co1/3(Nb1-xW5x/6)2/3)O3 (0<x≤0.05) (BCWN) microwave dielectric ceramics have been prepared by solid-state reaction method. The microstructure and microwave dielectric properties of BCWN ceramics were investigated systematically in this paper. The results show that the sintering temperature decreases with the substitution of W6+. The Ba(Co1/3(Nb1-xW5x/6)2/3)O3 solid solution is formed with the small substitution of W6+ (x≤0.01). With the increase of x, the impurity phase BaWO4 occurrs and the grains become less homogeneous. Combined with the analysis of X-Ray Diffraction, the cation ordering degree on B-site increases in the sample of x=0.01, which leads to the decrease of the dielectric loss. However, the second phase BaWO4 inhibits the formation of the ordered structure with the reduction of sinterability. Due to the formation of BaWO4, the values of εr and τf of all samples decrease subsequently. The optimized microwave dielectric properties of Ba(Co1/3(Nb1-xW5x/6)2/3)O3 ceramics were obtained in the samples of x=0.01: εr=33.8, Q×f =110761 GHz, τf = -17 ppm/°C.

Studies on BaO-CeO2-TiO2 Microwave Dielectric Ceramics

2011 ◽  
Vol 197-198 ◽  
pp. 323-327 ◽  
Author(s):  
Yuan Xiao ◽  
Xiao Gu Huang ◽  
Qi Tu Zhang
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Different Temperatures ◽  
Dielectric Ceramics ◽  
Sintering Characteristics ◽  
Micro Structures ◽  
Different Content

BaO-CeO2-TiO2 microwave dielectric ceramics with the different content of TiO2 were fabricated by a solid-state reaction method using BaCO3, CeO2, TiO2 powders as starting materials in view of the dispute. The sintering characteristics, phase composition, micro-structures and microwave dielectric properties of BaO-CeO2-nTiO2 microwave dielectric ceramics with different n values sintered at different temperatures were investigated. The results showed that the sintering temperature of BaO-CeO2-nTiO2 microwave dielectric ceramics was lower (< 1300°C), and CeO2 didn’t tend to form polynary compounds. When n = 3, the sintered ceramics had excellent dielectric properties: εr ≈40.3, tanδ ≈1.02×10-3 (1 MHz); εr ≈ 41.2, Q•f =19922GHz (6.865 GHz), τf = +22 ppm/°C .

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