STRUCTURAL AND RF PROPERTIES OFCo2ZFERRITE FOR ANTENNA SUBSTATE

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3731-3737 ◽  
Author(s):  
JAE-SIK KIM ◽  
EUI-SUN CHOI ◽  
YOUNG-HIE LEE ◽  
KI-WON RYU
Keyword(s):  
Loss Tangent ◽  
High Frequency ◽  
Sintering Temperature ◽  
Suitable Condition ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Permittivity And Permeability ◽  
Small Antenna ◽  
Electro Magnetic ◽  
Xrd Patterns

The sintering behavior and high frequency electro-magnetic properties of Ba3Co2Fe24O41ceramics were investigated for the small antenna application. All samples of the Ba3Co2Fe24O41ceramics were prepared by the solid-state reaction method and sintered at 1150°C 1400°C. From the XRD patterns of calcined Ba3Co2Fe24O41powders, the most suitable condition for calcining was 600°C–1000°C. Ba3Co2Fe24O41phase was observed in sintered Ba3Co2Fe24O41ceramics as main phase. Bulk densities increased with sintering temperature and decreased at 1400°C. Permittivity and permeability of the Ba3Co2Fe24O41ceramics increased or decreased with sintering temperature, respectively. On the other hand, loss tangent of permittivity and of permeability showed contrary tendency with permittivity and permeability. The permittivity and loss tangent of permittivity of Ba3Co2Fe24O41ceramics sintered at 1300°C were 19.896 and 0.171 at 210 MHz. and the measured value of permeability and loss tangent of permeability were 14.218 and 0.204, respectively.

The Structure-Property-Processing Relationship for Sintered Yttria-Stabilized Zirconia (YSZ)/Alumina Bioceramics

2013 ◽  
Vol 25 (04) ◽  
pp. 1350005 ◽  
Author(s):  
Sea-Fue Wang ◽  
Thomas Chung-Kuang Yang ◽  
Ya-Ting Hsu ◽  
Sheng-Yang Lee ◽  
Jen-Chang Yang
Keyword(s):  
Fracture Toughness ◽  
Relative Density ◽  
Sintering Temperature ◽  
High Hardness ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Structure Property ◽  
Stabilized Zirconia ◽  
Average Grain Size ◽  
Alumina Addition

The objective of this research is to study the effects of alumina addition on the microstructure-mechanical property relationship and sintering behavior of yttria (3 mol%)-stabilized zirconia (YSZ) ceramics. Well-dispersed YSZ / Al 2 O 3 ceramics containing 10–40 wt.% Al 2 O 3 were prepared by solid state reaction method. The relative density, average grain size, lattice parameters, microhardness, and fracture toughness of YSZ / Al 2 O 3 ceramics system sintered in the temperature range of 1250~1500°C as a function of Al 2 O 3 content were investigated. Experimental results showed that the ceramics with high Al 2 O 3 content and low sintering temperature tended to reveal low bulk densities. But the Al 2 O 3 content dependence on relative density for YSZ / Al 2 O 3 ceramics becomed deminishing when increasing the sintering temperature. Dense ceramics with composition of (80/20) ( YSZ / Al 2 O 3) and sintered at temperature of 1400°C and 1450°C revealed the optimal Vickers hardness and fracture toughness properties. These ceramics with high Al 2 O 3 content tended to reveal small grain sizes. The high sintering temperature governs the slow grain growth and high hardness in materials indicating the good correlation between microstructure of fabricated dense and mechanical properties.

scholarly journals SINTERING BEHAVIOR AND MICROWAVE DIELECTRIC PROPERTIES OF NOVEL LOW TEMPERATURE FIRING Bi3FeMo2O12 CERAMIC

2011 ◽  
Vol 01 (04) ◽  
pp. 379-382 ◽  
Author(s):  
DI ZHOU ◽  
LI-XIA PANG ◽  
JING GUO ◽  
YING WU ◽  
GAO-QUN ZHANG ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Reaction Method ◽  
Temperature Firing ◽  
Microwave Dielectric ◽  
Dielectric Performance

In the present work, a novel low temperature firing Bi 3 FeMo 2 O 12 ceramic was synthesized via the solid-state reaction method. The monoclinic Bi 3 FeMo 2 O 12 phase can be formed at a low temperature 670°C. A relative density above 96% can be obtained when sintering temperature is above 800°C. The Bi 3 FeMo 2 O 12 ceramic sintered at 845°C for 2 h shows high microwave dielectric performance with a permittivity ~27.2, a Qf value of 14,500 GHz and a temperature coefficient of -80 ppm/°C. It might be a candidate for low temperature co-fired ceramics technology.

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.

Effects of zinc substitution on the dielectric properties of Ca5Nb4TiO17 microwave ceramics

2013 ◽  
Vol 03 (04) ◽  
pp. 1320003 ◽  
Author(s):  
Chunchun Li ◽  
Xiaoyong Wei ◽  
Haixue Yan ◽  
Michael J. Reece
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Potential Candidate ◽  
Strongly Correlated ◽  
Microwave Ceramics ◽  
Microwave Dielectric ◽  
Method Effects

Ca 5-x Zn x Nb 4 TiO 17 ceramics with 0 ≤ x ≤ 0.4 were prepared through a solid-state reaction method. Effects of zinc substitution on sintering behavior and microwave dielectric properties of Ca 5 Nb 4 TiO 17 ceramics were investigated. The sintering temperature was significantly lowered from 1480°C for pure Ca 5 Nb 4 TiO 17 to 1260°C for x = 0.4. The microwave dielectric properties are strongly correlated with the composition. It is worth noting that the temperature coefficient of resonant frequency (τf) displays a tendency toward positive value, ranging from −126.4 ppm/°C to −8.6 ppm/°C. A temperature stable microwave ceramic with dielectric constant of 52 and Q × f value of 9937 GHz is achieved at x = 0.4 and is a potential candidate for application as cores in dielectrically loaded antennas.

High Frequency Magnetic Properties of A Composite Material Prepared from Z-Type Hexaferrite and Bi2O3

2013 ◽  
Vol 833 ◽  
pp. 99-102
Author(s):  
Zhen Hua Cao ◽  
Man Gui Han ◽  
Meng Ran Guan ◽  
Zhen Jiang Song ◽  
Long Jiang Deng
Keyword(s):  
Magnetic Properties ◽  
Composite Material ◽  
Solid State ◽  
High Frequency ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Q Factor ◽  
Reaction Method ◽  
High Q ◽  
Microstructure And Magnetic Properties

The composite materials are composed by Z-type hexaferrite and Bi2O3 by solid-state reaction method. Crystalline phase, microstructure and magnetic properties were measured by XRD, SEM, and VNA. The results showed that the sintering temperature and the content of Bi2O3 can effectively affected both uniformity and densification. What's more, Z-type hexaferrite mixed with proper content of Bi2O3 and sintered at a low temperature presented a high Q-factor in a high frequency.

Processing and Properties of PSZN-PZT Quaternary Piezoelectric Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 205-208
Author(s):  
Li Feng Wang ◽  
Qingchi Sun
Keyword(s):  
Electric Field ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
High Electric Field ◽  
Sintering Behavior ◽  
Synthesis Methods ◽  
Xrd Patterns

Piezoelectric Pb(Sn1/3Nb2/3)O3-Pb(Zn1/3Nb2/3)O3-PbTiO3-PbZrO3 (PSZN-PZT) quarternary ceramics with varying Zr/Ti ratio, which locate in the vicinity of the morphotropic phase boundary (MPB), were prepared by the conventional calcination route. The conventional and twice synthesis methods were compared. XRD patterns indicated the more complete perovskite phase was formed by the twice synthesis methods. The sintering behavior was investigated. The microstructure was studied and the piezoelectric and ferroelectric properties and the properties under high electric field were determined. The optimized results were obtained when the ratio of Zr/Ti is 43/45 and the sintering temperature is 1260°C.

Influence of sintering temperature on structure, microstructure and piezoelectric properties of doped BZT–BCT ceramics

2017 ◽  
Vol 31 (02) ◽  
pp. 1650258 ◽  
Author(s):  
Anh Tuan Dang ◽  
Thanh Tung Vo ◽  
Van Chuong Truong ◽  
Van Hong Le
Keyword(s):  
Solid State ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Zno Nanoparticle ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Best Parameters ◽  
Better Than

This work reports the influence of sintering temperature on structure, microstructure and piezoelectric properties of 0.48 Ba(Zr[Formula: see text]Ti[Formula: see text])O3–0.52 (Ba[Formula: see text]Ca[Formula: see text])TiO3(BZT–BCT) doped with ZnO nanoparticle ceramics manufactured by a conventional solid state reaction method. By increasing sintering temperature, the piezoelectric behaviors were improved and rose up to the best parameters at a sintering temperature of 1450[Formula: see text]C ([Formula: see text] pC/N and [Formula: see text]). The corresponding properties of undoped BZT–BCT ceramics were investigated as a comparison. The received results show that the sintering behavior and piezo-parameters of doped BZT–BCT samples are better than the undoped BZT–BCT samples at each sintering temperature.

scholarly journals Sintering Behavior and Microwave Dielectric Properties of MgO-2B 2 O 3 - Xwt %H 3 BO 3 - Ywt %BCB Ceramics

2021 ◽  
Author(s):  
Haiquan WANG ◽  
Shixuan LI ◽  
Kangguo WANG ◽  
Huanfu ZHOU ◽  
Xiuli Chen
Keyword(s):  
Dielectric Properties ◽  
Bulk Density ◽  
Single Phase ◽  
Sintering Temperature ◽  
Microstructural Analysis ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Microwave Dielectric

Abstract The bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 series ceramics synthesized by solid-state reaction method were systematically studied in this paper. X-ray diffraction and microstructural analysis revealed that the as-prepared MgO-2B2O3 ceramics possessed a single-phase structure with rod-like morphology. Through the investigation of the effects of different dosages of H3BO3 and BCB on bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 ceramics, the optimum sintering temperature was obtained at an addition of 30wt%H3BO3 and 8wt%BCB and the sintering temperature was reduced to 825 oC. The addition of 40wt %H3BO3 and 4 wt%BCB increased the quality factor Q×f, permittivity εr and temperature coefficient of resonance frequency τf of MgO-2B2O3 to 44,306 GHz, 5.1 and -32 ppm/oC, respectively, meeting the criteria of low-temperature co-fired ceramics.

Influence of ZnO and Nb2O5 Additions on Sintering Behavior and Microwave Dielectric Properties of (Mg0.95Ca0.05 )TiO3 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1184-1188 ◽  
Author(s):  
Chun Ya Luo ◽  
Ming Zhe Hu ◽  
Quian Huang ◽  
Yang Fu ◽  
Hao Shuang Gu
Keyword(s):  
Dielectric Properties ◽  
Oxygen Vacancies ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Sintering Behavior ◽  
Doping Content ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Xrd Patterns

The influence of ZnO and Nb2O5 additions on the sinterability, microstructure and microwave dielectric properties of (Mg0.95Ca0.05)TiO3 (abbreviated as 95MCT hereafter) ceramic is investigated. XRD patterns indicate that MgTi2O5 secondary phase can be effectively suppressed by ZnO and Nb2O5 additions, which is beneficial for improving the microwave dielectric properties. Appropriate amount of Nb2O5 addition can effectively improve the Qf value of 95MCT ceramic, which is suggested to be ascribed to the reduced oxygen vacancies. When the ZnO: Nb2O5 mole ratio is 1.5 and the co-doping content is 0.25wt%, the optimal microwave dielectric properties can be obtained Qf=72730GHz(6.8GHz), εr=20.29 and τf=-6.84ppm/°C and the sintering temperature of 95MCT is lowered from 1400°C to 1320°C.

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