Dielectric Characteristics of (Ca0.2Sr0.8)3(ZrxTi1-x)2O7 Ceramics at Microwave Frequencies

2017 ◽  
Vol 898 ◽  
pp. 392-398
Author(s):  
Wen Shiush Chen ◽  
Hsin Han Tung ◽  
Cheng Hsing Hsu ◽  
Ching Fang Tseng ◽  
Chun Hung Lai ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Temperature Sensing ◽  
Solid State Method ◽  
Dielectric Characteristics ◽  
Microwave Frequencies ◽  
Suitable Material ◽  
Microwave Dielectric ◽  
Microwave Ceramic ◽  
State Method

(Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) ceramic prepared by the solid state method was investigated for its microstructure and microwave dielectric properties. The correlation between the microstructure and microwave dielectric properties was also investigated. By increasing x from 0.01 to 0.06, the dielectric constant and Q×f value of the specimen could be increased from 72 to a maximum of 74, and from 11000 GHz to a maximum of 18000 GHz, respectively. The εr value of 74, the Q×f value of 18,000 GHz, and the τf value of 418 ppm/oC were obtained for (Ca0.2Sr0.8)3(Zr0.06Ti0.94)2O7 ceramics sintering at 1520oC for 4h, and (Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) is proposed as a suitable material candidate for application in microwave ceramic temperature sensing antenna.

Dielectric Properties of BaTi5O11 Ceramics at Microwave Frequencies

2013 ◽  
Vol 677 ◽  
pp. 153-156 ◽  
Author(s):  
Cheng Hsing Hsu ◽  
Wen Shiush Chen ◽  
Hsin Han Tung ◽  
Pai Chuan Yang ◽  
Jenn Sen Lin
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Microwave Dielectric Properties ◽  
Solid State Method ◽  
Passive Components ◽  
Microwave Frequencies ◽  
Suitable Material ◽  
Microwave Dielectric ◽  
Microwave Ceramic ◽  
State Method

Microwave dielectric properties of BaTi5O11ceramics prepared by solid-state method with various calcining temperatures and sintering temperatures have been discussed. The εrvalue of 42.8, the Q×f value of 44,000 GHz, and the τfvalue of 42.4 ppm/oC were obtained for BaTi5O11ceramics sintering at 1100oC for 4 h. BaTi5O11is proposed as a suitable material candidate for application in high selective microwave ceramic passive components.

Low Temperature Sintering and Microwave Dielectric Properties of Zinc Titanate Ceramics for LTCC Applications

2008 ◽  
Vol 368-372 ◽  
pp. 179-182
Author(s):  
Zong Chi Liu ◽  
Dong Xiang Zhou ◽  
Shu Ping Gong
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Solid State Method ◽  
Zinc Titanate ◽  
Microwave Dielectric ◽  
Conventional Solid State Method ◽  
State Method ◽  
Titanate Ceramics

The effects of CuO-MoO3 addition on the sintering behavior and microwave dielectric properties of ZnO-TiO2 ceramics were investigated. ZnO-TiO2 ceramics were prepared with conventional solid-state method and sintered at temperatures from 850 to 1050 °C. The sintering temperature of ZnO-TiO2 ceramics with CuO-MoO3 addition could be effectively reduced to 950 °C due to the liquid phase effects resulting from the additives. A proper amount of CuO-MoO3 addition could effectively improve the densification and microwave dielectric properties of ZnO-TiO2 ceramics. ZnO-TiO2 ceramics with 3 wt% addition sintered at 950 °C for 4 h exhibited better microwave dielectric properties as follows: εr of 26.8, a Q×f value of 16780 GHz at 5.42 GHz, and a τ f value of +34.7 ppm/°C.

Effect of Sintering Temperature on CuO Doped Barium Zinc Tantalate (BZT) Dielectric Properties

2016 ◽  
Vol 840 ◽  
pp. 8-13
Author(s):  
Hidayani Jaafar ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Relative Density ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Method ◽  
Microwave Dielectric ◽  
Constant E ◽  
State Method ◽  
Tan Δ

The structure and dielectric properties of Barium Zinc Tantalate (BZT) doped by copper oxide (CuO) with a variety of values of mol% doping from 0, 0.1, 0.25, 1.0, 1.5 and 2.5 were prepared using a solid state method. The addition of CuO did not disturb the 1:2 ordering structure of the BZT ceramic. The grain size increased when the addition of doping increased. A small amount of doping elements increased the relative density. The dielectric constant (ɛr) value of the BZT significantly improved with the addition of the CuO for the specimens sintered at 1250°C and it could be explained by the increase of the relative density. The tan δ of the CuO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CuO content increases. Meanwhile, for the percentage of bandwidth (%BW) it is shown that the best result is produced when it is doped with 0.25 mol% CuO and sintered at 1250°C. The best microwave dielectric properties obtained were ɛr=70.28, tan δ = 0.024, %BW = 7.83 which occurred for the 0.25 mol% doped CuO and when sintered at 1250°C/4 h.

scholarly journals Effects of (Mg1/3Sb2/3)4+ Substitution on the Structure and Microwave Dielectric Properties of Ce2Zr3x(Mg1/3Sb2/3)3-3x(MoO4)9 Ceramics

2020 ◽  
Author(s):  
Zhou Xu ◽  
Sun Jiajia ◽  
Zhang Ningkang ◽  
Sun Huazhang ◽  
Tao Wenhong ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Far Infrared ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Microwave Dielectric ◽  
Refinement Method ◽  
Traditional Solid State Method

Abstract Ce2[Zr1-x(Mg1/3Sb2/3)x]3(MoO4)9 (0.02≤x≤0.10) ceramics were prepared well through the traditional solid-state method. A single phase, belonging to the space group of R-3c, was detected by using X-ray diffraction at sintering temperatures ranging from 700 to 850 °C. The crystallization micro-structural of specimens was examined by applying Scanning electron microscopy. The structural refinement of these samples was investigated in detail by performing the Rietveld refinement method. The intrinsic properties were calculated and explored via far-infrared reflectivity spectroscopy. The correlations between the chemical bonds parameters and microwave dielectric properties were calculated and analyzed by P-V-L theory. Ce2[Zr0.94(Mg1/3Sb2/3)0.06]3(MoO4)9 ceramics with excellent dielectric properties: εr = 10.37, Q×f = 71748 GHz and τf = −13.6 ppm/°C sintered at 725 °C for 6 hours.

scholarly journals Structure, Defects and Microwave Dielectric Properties of Al-doped and Al/Nd Co-doped Ba4Nd9.33Ti18O54 Ceramics

2021 ◽  
Author(s):  
Weijia Guo ◽  
Zhiyu Ma ◽  
Yu Luo ◽  
Yugu Chen ◽  
Zhenxing Yue ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Resonant Frequency ◽  
Microwave Dielectric Properties ◽  
Relative Dielectric Constant ◽  
Doping Amount ◽  
Solid State Method ◽  
Depolarization Current ◽  
Structure Defects ◽  
Microwave Dielectric ◽  
Co Doped

Abstract Ba4Nd9.33Ti18-zAl4z/3O54 (BNT-A, 0 ≤ z ≤ 2) and Ba4Nd9.33+z/3Ti18-zAlzO54 (BNT-AN, 0 ≤ z ≤ 2) ceramics were prepared by solid state method, and the effects of the two doping methods on microwave dielectric properties were compared. As the doping amount z increased, the relative dielectric constant (εr) and the temperature coefficient of resonant frequency (τf) values of the ceramics decreased, and the quality factor (Q, usually expressed by Q×f, where f is the resonant frequency) of the ceramics obviously increased when z ≤ 1.5. With the same z value, the εr and Q×f values of Al/Nd co-doped ceramics are both higher than those of Al-doped ceramics. Rietveld refinement, Raman spectroscopy and thermally stimulated depolarization current (TSDC) technique were applied to clarify the relationship among the structure, defects and microwave dielectric properties. It is shown that the Q×f values of those ceramics were closely related to the strength of the A-site cation vibration and the concentration of oxygen vacancies (B). Excellent microwave dielectric properties of εr = 72.2, Q×f = 16480 GHz, and τf = +14.3 ppm/℃ were achieved in BNT-AN ceramics with z = 1.25.

HIGH THERMAL STABILITY OF MICROWAVE DIELECTRIC PROPERTIES OF CaTi1-x(Nb1/2Fe1/2)xO3 CERAMICS

2011 ◽  
Vol 01 (04) ◽  
pp. 417-427 ◽  
Author(s):  
A. D. S. BRUNO COSTA ◽  
M. C. ROMEU ◽  
R. C. S. COSTA ◽  
T. S. M. FERNANDES ◽  
F. W. DE O. AMARANTE ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Solid Solutions ◽  
Microwave Dielectric Properties ◽  
Titanium Content ◽  
Milling Process ◽  
Solid State Method ◽  
Small Shift ◽  
X Ray ◽  
Microwave Dielectric

This paper presents a study of the structure and microwave properties of [Formula: see text] substituted into the Ti 4+ site of calcium titanate ceramics. The structural and dielectric properties of solid solutions in CaTi 1-x( Nb 1/2 Fe 1/2)x O 3, was done. The microwave dielectric properties of solid solutions in CaTi 1-x( Nb 1/2 Fe 1/2)x O 3, (CNFTOX with x = 0.1 to x = 1) is discussed. The modified CaTiO3 (CTO) ceramics were prepared by a new procedure in the solid-state method. A study of the variations of the ball-milling process was done. The calcinations were done at 900°C for 3 and 5 h respectively, and the sintering at 1100°C, for 3 h. The structural property studies of the ceramics were investigated by X-ray diffraction (XRD) and Raman spectroscopy. The X-ray analysis showed that all samples have an orthorhombic structure. The refinement analysis of all samples were also duly performed and discussed. The nine scattering bands centered at 183, 227, 247, 288, 338, 470, 490 and 805 cm-1 were observed. Several peaks presented a small shift as a function of the x value. All Raman spectra in the studied samples showed a small band at 805 cm-1, which is a function of the x value. The dielectric permittivity and loss at microwave frequencies (MW) were investigated. For both calcination treatments (900°C for 3 and 5 h), the dielectric permittivity decreased with a decrease of the titanium content. Dielectric permittivity values in the range of 20 to 80 were obtained. It was also observed that a higher number of balls in the milling process contribute to the increase of the εr values. The CNFTO has an excellent microwave property at x = 0.6, with a temperature coefficient of resonant frequency (τf) near zero (τf = 2.8 ppm/°C).

Dielectric Properties of a New Ceramic System (1-x)(Mg0.95Zn0.05)2TiO4-x(Ca0.8Sr0.2)TiO3 at Microwave Frequencies

2020 ◽  
Vol 830 ◽  
pp. 37-42
Author(s):  
Shih Sheng Liu ◽  
Shiuan Ho Chang ◽  
Yuan Bin Chen
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Low Loss ◽  
Microwave Frequencies ◽  
Solid State Route ◽  
Microwave Dielectric ◽  
System 1 ◽  
Quality Factor Q

The microwave dielectric properties and microstructures of the (1-x)(Mg0.95Zn0.05)2TiO4-x (Ca0.8Sr0.2)TiO3 ceramics prepared using the conventional solid-state route were investigated. The structure and microstructure were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Ilmenite-structured (Mg0.95Zn0.05)TiO3 was detected as a second phase. The coexistence of the second phase, however, did not degrade the dielectric properties of the specimen because the phases were compatible. At x = 0.07, a dielectric constant (εr) of ~17.86, a quality factor (Q×f) value of ~ Q×f~133,600 Hz (at 10 GHz), and a temperature coefficient of resonant frequency (τf) of ~ –5ppm/°Cwere obtained for 0.93(Mg0.95Zn0.05)2TiO4-0.07(Ca0.8Sr0.2)TiO3 ceramic sintered at 1240°C for 4 hr. The dielectric is proposed as a candidate material for low-loss microwave and millimeter wave applications.

Effect of bond valence on microwave dielectric properties of (Pb1−xCax)(Mg0.33Ta0.67)O3 ceramics

2001 ◽  
Vol 16 (3) ◽  
pp. 817-821 ◽  
Author(s):  
Heung Soo Park ◽  
Ki Hyun Yoon ◽  
Eung Soo Kim
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Bond Valence ◽  
Negative Deviation ◽  
Complex Perovskite ◽  
Microwave Frequencies ◽  
Microwave Dielectric ◽  
Dielectric Polarizability ◽  
A Site ◽  
The Relationship

The relationship between the dielectric properties of the complex perovskite (Pb1−xCax)(Mg0.33Ta0.67)O3 ceramics, where 0.45 ≤ × ≤ 0.60, and the dielectric polarizability, related to bond valences of A-site ions, was investigated at microwave frequencies. As the Ca content (x) increased, the deviation of the observed dielectric polarizabilities, calculated by the Clausius–Mosotti equation from the theoretical values calculated by the additivity rule of dielectric polarizability, decreased from −3% to −0.69%. It was found that this deviation was related to the bond valence of the A-site. Smaller negative deviation corresponded to the cations with lower bond valence, and larger negative deviation corresponded to the cations with higher bond valence. Also, the temperature coefficient of resonant frequency (TCF) was affected by the bond valence of the A-site, and then TCF decreased with decreasing bond valence of the A-site in ABO3 perovskite compounds.

Microwave dielectric properties of Ba4LaTi0.3Sn0.7Nb3O15 ceramic

2014 ◽  
Vol 28 (15) ◽  
pp. 1450092 ◽  
Author(s):  
Abdul Manan ◽  
Imtiaz Hussain
Keyword(s):  
Dielectric Properties ◽  
Single Phase ◽  
Least Squares Method ◽  
Microwave Dielectric Properties ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Microstructural Investigation ◽  
Microwave Frequencies ◽  
Microwave Dielectric ◽  
Lcr Meter

Ba 4 LaTi 0.3 Sn 0.7 O 15 ceramic was prepared through conventional solid state mix oxide route followed by characterization using X-ray diffraction (XRD) and scanning electron microscope (SEM) for phase and microstructural investigation. The dielectric properties at low and microwave frequencies were measured using LCR meter and vector network analyzer. XRD results revealed single phase ceramics and the microstructure was comprised of compact grains with size ranging from 4–12 μm. The lattice parameters refined by the least squares method were a = b = 5.7680(2) Å, c = 11.7491(6) Å, V = 337.81 Å3 and Z = 1. Optimum properties i.e., εr~44.6, Qufo~15, 500 GHz and τf~2.05 ppm /° C were achieved for Ba 4 LaTi 0.3 Sn 0.7 Nb 3 O 15 ceramic sintered at 1475°C for 4 h.

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