scholarly journals Microwave dielectric properties of Na+-substituted CaMg0.9Li0.2Si2O6 ceramics

2022 ◽  
Vol 355 ◽  
pp. 01024
Author(s):  
Fangyi Huang ◽  
Hua Su ◽  
Xiaoli Tang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bulk Density ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Low Dielectric Constant ◽  
Second Phase ◽  
Experimental Sample ◽  
Low Dielectric ◽  
Microwave Dielectric

Ceramics with low dielectric constant are widely used in high frequency substrates. The low temperature sintered CaMg0.9-xNa2xLi0.2Si2O6(x = 0–0.05 and 0.1) ceramics with low dielectric constant and dielectric loss were prepared by the traditional solid-state reaction method, with 0.5wt%LBSCA additive. The XRD patterns of the samples were obtained by X-ray diffraction and it was found that there were three ceramic components, CaMgSi2O6, CaSiO3 and Na2MgSiO4, which indicated that the experimental sample was a multiphase ceramic system. Through the trend of bulk density as functions of the content of substitution and the change of SEM morphology, it could be found that appropriate amount of Na+ substitution can promote the grain growing and the densification of ceramics. Results demonstrated that both the Q × f and εr were relevant to bulk density and the second phase. The τf was also affected by the second phase to some extent. In particular, the ceramics sintered at 925 °C for 3h possessed the desirable microwave dielectric properties for LTCC application: εr = 7.03, Q × f = 17,956 GHz, and τf= −79 ppm/°C.

Low-Temperature Sintering and Microwave Dielectric Properties of (Ca0.9Mg0.1)SiO3 Ceramic with Li2CO3 Addition

2014 ◽  
Vol 602-603 ◽  
pp. 748-751 ◽  
Author(s):  
Xin Hui Zhao ◽  
Min Jia Wang ◽  
Qi Long Zhang ◽  
Hui Yang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Low Dielectric Constant ◽  
Low Temperature Sintering ◽  
Low Dielectric ◽  
Densification Temperature ◽  
Microwave Dielectric

(Ca0.9Mg0.1)SiO3ceramics possess a low dielectric constant and a highQfvalue, however, the densification temperature of (Ca0.9Mg0.1)SiO3ceramics is higher than 1280°C. In this paper, the effect of Li2CO3addition on sinterability and dielectric properties of (Ca0.9Mg0.1)SiO3ceramics were studied. The phase presence and surface morphology were determined by XRD and SEM techniques, respectively. CaSiO3and Ca2MgSi2O7phases were observed. With the addition of >2.0 wt% Li2CO3, the sintering temperature of (Ca0.9Mg0.1)SiO3ceramic was significantly lowered, reaching to 1070°C. (Ca0.9Mg0.1)SiO3ceramics with 4wt% Li2CO3sintered at 1070°C for 3 h shows excellent dielectric properties:εr=5.91,Qf= 15300GHz (at 10GHz).

B-O Bond Character and Microwave Dielectric Properties of (1-x)CaTiO3-xCa(Zn1/3Nb2/3)O3 Perovskite Ceramics

2009 ◽  
Vol 421-422 ◽  
pp. 69-72
Author(s):  
Jie Shen ◽  
Wen Chen ◽  
Jing Zhou ◽  
Jie Zhu ◽  
Qiong Lei
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Dielectric Materials ◽  
Solid State Reaction Method ◽  
Dielectric Constants ◽  
Identical Result ◽  
Microwave Dielectric ◽  
Calculation Results ◽  
The Relationship

The relationship between the character of the B-site cation–oxygen bond and the microwave dielectric properties in perovskites dielectric materials was studied in this paper. The atomic net charge of CaTiO3 (CT) and Ca(Zn1/3Nb2/3)O3 (CZN) was calculated respectively. The calculating result implies that the covalency of B-O bonds in CZN is stronger than that in CT. This predicted that the dielectric constant and loss of the ceramics will decrease after CZN incorporated in CT. To confirme the prediction, (1-x)CT-xCZN microwave dielectric ceramics were prepared by solid state reaction method with ZnNb2O6 as precursor. The structure analysis in terms of tolerance factor gives an identical result as calculation. The microwave dielectric properties, such as dielectric constants, Q×f values and τf were studied as a function of composition. With x increasing from 0.2 to 0.8, the dielectric constant linearly decreases from 109 to 49.37, the Q×f value increases from 8,340 to 13,200 GHz, and τf decreases from 321 to -18 ppm/°C. The properties trends are consistent with the previous calculation results, and confirm the relationship between the character of B-O bond and dielectric properties.

Microwave Dielectric Properties of (1-x)(Ca0.61Nd0.26)TiO3–x(Li0.5Sm0.5)TiO3

2007 ◽  
Vol 336-338 ◽  
pp. 287-289
Author(s):  
Wei Wang ◽  
Zi Long Tang ◽  
Zhong Tai Zhang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Temperature Coefficients ◽  
Microwave Dielectric ◽  
Optimum Parameters ◽  
Xrd Patterns

(1-x)(Ca0.61Nd0.26)TiO3-x(Li0.5Sm0.5)TiO3 (0.2 ≤ x ≤ 0.7) ceramics were prepared by solid-state reaction method and the microwave dielectric properties of the resultant materials at different (Li0.5Sm0.5)TiO3 contents were investigated. A single phase of perovskite in all samples was confirmed by XRD patterns. With increasing (Li0.5Sm0.5)TiO3 content, Q×f value and dielectric constant (εr) decrease slightly and the temperature coefficients of the resonant frequency (τf) of the specimens decreases noticeably. The optimum parameters, i.e.,εr = 109, Q×f = 5259 GHz and τf = ~0 ppm/°C, for the composition of 0.4(Ca0.61Nd0.26)TiO3-0.6(Li0.5Sm0.5)TiO3 was obtained when keep the calcination temperature at 1250°C for 3 h.

Preparation and Microwave Dielectric Properties of xBaZn2Ti4O11-(1-x)BaNd2Ti4O12 Ceramics

2017 ◽  
Vol 726 ◽  
pp. 210-214
Author(s):  
Xu Wang ◽  
Ren Li Fu ◽  
Yue Xu ◽  
Yang Yang ◽  
Jun De Cai ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Phase System ◽  
Microwave Ceramics ◽  
Two Phase ◽  
Microwave Dielectric ◽  
X Band ◽  
High Dielectric

xBaZn2Ti4O11–(1-x)BaNd2Ti4O12 (x = 0.18–0.30) ceramics were prepared by solid-state reaction method and their microwave dielectric properties were investigated with the purpose of finding a microwave ceramics with high dielectric constant (εr), high quality factor (Q×f ) and zero temperature coefficient of resonant frequency (τf).The two phase system BaZn2Ti4O11–BaNd2Ti4O12 affected the unit cell volume and the microstructure, the microwave dielectric properties (εr, Q×f, τf). As increasing x from 0.18 to 0.30, the main phase composition was BaNd2Ti4O12. Therefore, the εr decreased from 64.9 to 60.3 and the Q×f values raised from 11,350GHz to 13,210GHz, and the τf values decreased from 7ppm/° to -5ppm/°.The 0.22BaZn2Ti4O11–0.78BaNd2Ti4O12 ceramics sintered at 1250°C for 4 h displayed the best dielectric constant εr,Q×f and τf, as 63.9, 12380 GHz and-0.1 ppm/° respectively.

The Effect CuO Additive on the Microwave Dielectric Properties of Mg(Zr0.05Ti0.95)O3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 199-203 ◽  
Author(s):  
Ching Fang Tseng
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Liquid Phase ◽  
Solid State Reaction ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Microwave Dielectric ◽  
Second Phases

The microwave dielectric properties of the Mg(Zr0.05Ti0.95)O3ceramics with CuO addition were investigated. All specimens were prepared by solid-state reaction method and sintered at 1270-1420°C for 4 h. When CuO was added, the second phases of MgTi2O5, TiO2and liquid phase were produced. For specimens with 1.5 wt% CuO sintered at 1300°C, the dielectric constant,Q´fand tfvalues are 18.2, 223000 GHz and -2 ppm/°C, respectively.

Preparation of BCB Powder and its Effects on the Sintering Behaviour and Microwave Dielectric Properties of MCT Ceramics

2012 ◽  
Vol 472-475 ◽  
pp. 2107-2110 ◽  
Author(s):  
Jin Liang Huang ◽  
Yong Jun Gu ◽  
Li Hua Li ◽  
Qian Li ◽  
Zhong Yan ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Second Phase ◽  
Phase Effect ◽  
Sintering Aid ◽  
Reaction Method ◽  
Microwave Dielectric ◽  
Sintering Behaviour

The BCB (BaCu(B2O5)) powders were synthesized by solid state reaction method and its effects on the microstructures, the phase formation and the microwave dielectric properties of MCT (Mg0.95Ca0.05TiO3) ceramics were investigated. BaO and B2O3 first forms BaB2O4, and then BaB2O4 reacts with CuO forming BCB. The sintering temperature of MCT ceramics with as-synthesized BCB addition can be effectively lowered from 1450°C to 1100°C due to the liquid phase effect. The formation of second phase (MgTi2O5) was restrained. The 3wt% BCB-doped MCT ceramics sintered at 1100°C for 3h have optimum microwave dielectric properties of Kr=21.5, Q×f=28000GHz, and TCF=-3.3ppm/°C. Obviously, BCB could be a suitable sintering aid that improves densification and microwave dielectric properties of the MCT ceramics.

Sintering, Microstructure and Dielectric Properties of Ca-Al-B-Si-O Glass/Al2O3 Composites with Various SiO2 Content

2011 ◽  
Vol 130-134 ◽  
pp. 1516-1519
Author(s):  
Ming Liu ◽  
Hong Qing Zhou ◽  
Hai Kui Zhu ◽  
Min Liu ◽  
Jian Xin Zhao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Silicon Dioxide ◽  
Bulk Density ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Tan Δ ◽  
Silicon Dioxide Content

The effects of silicon dioxide addition on the sintering, microstructure and microwave dielectric properties of Ca-Al-B-Si-O glass/Al2O3 composites were investigated. Results show that: Increasing the silicon dioxide content in the glass leads to the corresponding rise of bulk density, dielectric constant of the LTCC materials and the decrease of its dielectric loss and porosity. A bulk density of 2.92 g·cm-3, a porosity of 0.2%, aεr value of 7.11 and a tan δ value of 0.00096(measured at 10 MHz) are obtained for 68 wt% silicon dioxide of the samples sintered at 875°C for 30 min.

Dielectric properties of plasma-spray-deposited BaTiO3 and Ba0.68Sr0.32TiO3 thick films

2003 ◽  
Vol 18 (5) ◽  
pp. 1227-1231 ◽  
Author(s):  
K. Ahn ◽  
B. W. Wessels ◽  
S. Sampath
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Plasma Spray ◽  
Interfacial Layer ◽  
Thick Films ◽  
Low Dielectric Constant ◽  
Second Phase ◽  
Spray Process ◽  
Low Dielectric ◽  
Deposited Films

The dielectric properties of high-k dielectric BaTiO3 and Ba0.68Sr0.32TiO3 thick films deposited on alumina substrates using a plasma-spray process were investigated. The as-deposited films were predominantly crystalline but contained an amorphous second phase, the amount of which depended on spray conditions. The effect of the spray conditions on crystallinity was studied and related to the dielectric properties of the films. The presence of a low dielectric constant interfacial layer in plasma-spray-deposited films was determined from the dependence of the dielectric constant on film thickness. After annealing at 500 °C for 20 h in air, the crystallinity and dielectric constant increased. Annealing was also found to affect the interfacial layer properties.

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.

Sign in / Sign up

Export Citation Format

Share Document