Preparation and Investigation on Properties of the MgTiO3-CaTiO3 Microwave Ceramic Materials

2014 ◽  
Vol 997 ◽  
pp. 419-423 ◽  
Author(s):  
Li Dong ◽  
Gui Xia Dong ◽  
Yuan Yuan Li ◽  
Xi Zhang
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Volume Density ◽  
Second Phase ◽  
Pressureless Sintering ◽  
Solid Reaction ◽  
Reaction Method ◽  
Microwave Ceramic ◽  
Sintering Method

The MgTiO3 and CaTiO3 powders were synthesized by solid reaction method, and MgTiO3-CaTiO3 ceramic was prepared using pressureless sintering method. The experiment prepared MgTiO3-CaTiO3 ceramics with high compactness and stable permittivity by the way of changing the mole ratio of MgTiO3 and CaTiO3 to investigate the effect of CaTiO3 on the performances of MgTiO3-CaTiO3 ceramics. The results show that Mg2TiO4 formed as second phase during sintering. Volume density and dielectric constant of MgTiO3-CaTiO3 ceramics with 10%mol CaTiO3 reach maximum of 3.612g/cm3 and 17.8, respectively, under 1460°C sintering temperature. And for the MgTiO3-CaTiO3 ceramics with 5%mol CaTiO3 the maximum values which are 3.5g/cm3 and 16.6, respectively, appear under 1510°C sintering temperature.

Sn-doped BaO–TiO2–ZnO Microwave Ceramics

2002 ◽  
Vol 17 (6) ◽  
pp. 1550-1552 ◽  
Author(s):  
Wu Shunhua ◽  
Wang Guoqing ◽  
Zhao Yushuang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Volume Resistivity ◽  
Ceramic Materials ◽  
Microwave Ceramics ◽  
Microwave Ceramic ◽  
Tan Δ

Sn-doped BaO–TiO2–ZnO (BTZ) microwave ceramic materials were investigated as a function of SnO2 content. Addition of a small amount of SnO2 (0.01–0.06 wt%) lowered the sintering temperature of the system to 1160 °C and also greatly reduced the dielectric loss (tan δ), which is closely related to the insulation resistivity. The Sn-doped BTZ materials were found to have excellent dielectric properties at 1 GHz with dielectric constant Ε ≈tangent tan δ ≤ 1 × 10−4, temperature coefficient of dielectric constant, αΕ = 0 ± 30 ppm/°C, and volume resistivity ρv ≥ 1013 ω cm.

scholarly journals Effect of Pressure on the Synthesis of Compound Ba0.7Ca0.3TiO3 on the Dielectric Constant

2020 ◽  
Vol 22 (1) ◽  
pp. 1
Author(s):  
Windarjoto Windarjoto ◽  
S Poniman ◽  
Made Hendra Hadinata
Keyword(s):  
Dielectric Constant ◽  
Ceramic Materials ◽  
Ferroelectric Ceramic ◽  
Ferroelectric Materials ◽  
Advanced Technology ◽  
Frequency Range ◽  
Solid Reaction ◽  
Reaction Method ◽  
Effect Of Pressure ◽  
Lcr Meter

Piezoelectric and ferroelectric ceramic materials are widely used for advanced technology. Barium Titanat is one of the ferroelectric materials that are still widely studied today. In this research, Ba0,7Ca0,3TiO3 was synthesized. The compound was synthesized by the solid reaction method with variations in pressure during the sample compacting process include 10, 20, and 30 kN. Samples in the form of solids (pellets) were calcined at 800 °C and sintered at 1000 °C for 4 hours respectively. The synthesized product was characterized by an LCR meter. The characterization results in the frequency range of 100-200000 Hz show that the pressure affects of the parameters value of the dielectric constant, especially at frequencies 100-10000 Hz. In that frequency range the dielectric constant decreases very sharply, then above 100 kHz the dielectric constant is almost unchanged with increasing frequency.

Influence of Various Tin Ion Doped Amount on the Dielectric Properties of BMNS Ceramics

2013 ◽  
Vol 380-384 ◽  
pp. 4258-4261
Author(s):  
Xin You Huang ◽  
Mu Sheng Huang ◽  
Chun Hua Gao ◽  
Yuan Zuo
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Pyrochlore Phase ◽  
Solid State Reaction Method ◽  
Second Phase ◽  
Doping Amount ◽  
Reaction Method ◽  
Ion Doping

Bi2(Mg1/3Nb2/3-xSnx)2O7(BMNS)(x=0.1,x=0.15,x=0.2,x=0.25 mol) ceramics was prepared by traditional solid-state reaction method and the influence of tin ion doped amount on the dielectric properties and structure of BMNS ceramics were investigated. The results show that all of the doped samples keep a single monoclinic pyrochlore phase and there is no second phase observed. The grain size of ceramics gradually increases, the dielectric constant decreases first and then increases, the dielectric loss increases first and then decreases and the density reduces with the increase of tin ion doped amount. The density of ceramics increases first then decreases with the increase of sintering temperature. The BMNS ceramics sintered at 980 °C with 0.25 mol tin ion doping amount has a biggest density and the best properties,whose εris 155(1MHz),tanδ is 0.0011(1MHz), the bulk density is 7.62 g/cm3.

Effect of Sintering Behavior on Microwave Properties of (Ca0.8Sr0.2)ZrO3 Ceramics for Resonators

2014 ◽  
Vol 787 ◽  
pp. 338-341
Author(s):  
Cheng Hsing Hsu ◽  
Chia Hao Chang ◽  
Wen Shiush Chen ◽  
Jenn Sen Lin ◽  
Chun Hung Lai
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Passive Components ◽  
Suitable Candidate ◽  
Solid State Route ◽  
Microwave Dielectric ◽  
Microwave Ceramic ◽  
Conventional Solid State Route

Microwave dielectric properties and microstructures of (Ca0.8Sr0.2)ZrO3 ceramics prepared by the conventional solid-state route have been studied. The values of the dielectric constant (εr) were 22-26. The Q×f values of 10400–11500 GHz were obtained when the sintering temperatures were in the range of 1400–1490°C. The temperature coefficient of the resonant frequency τf was not sensitive to the sintering temperature. The εr value of 26, the Q×f value of 11500 GHz, and the τf value of-9 ppm/°C were obtained for (Ca0.8Sr0.2)ZrO3 ceramics sintering at 1490°C. The ceramic, (Ca0.8Sr0.2)ZrO3 is proposed as a suitable candidate material for application in highly selective microwave ceramic passive components.

Preparation and Electrical Property of Calcia Stabilized Zirconia Ceramics

2014 ◽  
Vol 616 ◽  
pp. 157-165 ◽  
Author(s):  
Chang Lian Chen ◽  
Hong Quan Wang ◽  
Jia You Ji ◽  
Ma Ya Luo ◽  
Bo Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Property ◽  
Arrhenius Equation ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Cubic Phase ◽  
Pressureless Sintering ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Sintering Method

In this paper, using ZrO2 and Ca (NO3)•4H2O as raw materials, we prepared a series of calica stabilized zirconia (CSZ) ceramics by pressureless sintering method. The results show that the relative densities of all sintered samples are above 90%, and the sintered samples are composed of cubic, tetragonal and monoclinic ZrO2, and the main phase is cubic ZrO2 and tetragonal ZrO2. The content of cubic phase increases with the increase of sintering temperature and adding CaO content. The grain size of the sintered samples is relatively uniform and some pores exist. Increasing the additive amount of CaO, the conductivity first rises and then decreases, and the conductivity value of the sample containing 5wt% CaO is the maximum. When the sintering temperature is up to 1600 oC, the conductivity of the sample containing 5wt% CaO is up to 0.016S•cm-1 at 800 oC. Furthermore, the conductivity of sintered samples is increasing with the increase of test temperature according to the Arrhenius equation.

Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic

2011 ◽  
Vol 335-336 ◽  
pp. 699-703
Author(s):  
Hui Hui Tan ◽  
Zhu Xing Tang ◽  
Xia Zhao ◽  
He Zhang
Keyword(s):  
Bulk Density ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Nitriding Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Additives ◽  
Sic Ceramic ◽  
Sintering Method ◽  
Scanning Electron

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 °C, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 °C the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 °C

Effect of Y2O3 on the Sintering, Mechanical and Dielectric Properties of Mullite/h-BN Composites

2016 ◽  
Vol 848 ◽  
pp. 28-31
Author(s):  
Han Jin ◽  
Yong Feng Li ◽  
Zhong Qi Shi ◽  
Hong Yan Xia ◽  
Guan Jun Qiao
Keyword(s):  
Fracture Toughness ◽  
Dielectric Constant ◽  
Phase Composition ◽  
High Temperature ◽  
Dielectric Properties ◽  
Liquid Phase ◽  
Flexural Strength ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Different Temperatures

Mullite/10 wt. %h-BN composites with 5 wt. % Y2O3 additive were fabricated by pressureless sintering at different temperatures. The densification, phase composition, microstructure, mechanical and dielectric properties of the mullite/h-BN composites were investigated. With the addition of Y2O3, the sintering temperature of the mullite/h-BN composites declined, while the density, mechanical and dielectric properties all increased. The addition of Y2O3 promoted the formation of liquid phase at high temperature, which accelerated the densification. Besides, Y2O3 particles which were located at the grain boundaries inhibited the grain growth of mullite matrix. For the mullite/h-BN composites with Y2O3 additive, the appropriate sintering temperature was about 1600°C. The relative density, flexural strength, fracture toughness and dielectric constant of the Y2O3 doped mullite/h-BN composite sintered at 1600 °C reached 82%, 135 MPa, 2.3 MPa·m1/2 and 4.9, respectively.

Effects of Mg2SiO4 Addition on the Microstructure and Dielectric Properties of MgTiO3-CaTiO3 Ceramics

2013 ◽  
Vol 675 ◽  
pp. 200-204
Author(s):  
Fei Shi ◽  
Peng Cheng Du ◽  
Jing Xiao Liu ◽  
Ji Wei Wu ◽  
De Qing Chen ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Dielectric Loss ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Composite Ceramics ◽  
Reaction Method ◽  
Dielectric Ceramics

The Mg2SiO4-MgTiO3-CaTiO3 composite dielectric ceramics with different Mg2SiO4 addition amounts were prepared by solid state reaction method. The effects of Mg2SiO4 addition amounts on the microstructure and dielectric properties as well as sintering temperature of xMg2SiO4-(0.95-x)MgTiO3-0.05CaTiO3 (abbreviated as xMSTC, 0.25≦x≦0.75) composite ceramics were investigated. The results indicated that the sintering temperature of MgTiO3-CaTiO3 based ceramics with Mg2SiO4 addition could be lowered effectively to 1320~1340°C, and the dielectric constant decreased and dielectric loss increased gradually with the increase of Mg2SiO4 content. The 0.45MSTC ceramics containing 45 wt% Mg2SiO4 and sintered at 1340°C showed desirable dielectric properties with dielectric constant εr=13.3，dielectric loss tanδ=4.5×10-4 and temperature coefficient of relative permittivity τε =10 ppm/°C.

scholarly journals Methods to improve mechanical characteristics of ceramics on the basis of zirconium and hafnium diborides (Review)

2020 ◽  
Vol 10 (2) ◽  
pp. 180-190
Author(s):  
Ekaterina N. Portnova
Keyword(s):  
Crack Resistance ◽  
Mechanical Characteristics ◽  
Sintered Material ◽  
Ceramic Materials ◽  
Second Phase ◽  
Ceramic Samples ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Powder Particles ◽  
Sintering Method

This paper describes the main methods for improving the mechanical properties of ceramic materials based on zirconium and hafnium diborides, such as strength and crack resistance. Particular attention is paid to the influence of the sintering method, as well as additives introduced into the powder composition, in particular hard fibers, second-phase powder particles and “whiskers”, on the mechanical characteristics of the ceramics. On the basis of the analysis of literature data, it is shown that the spark plasma sintering (SPS) method allows to obtain ceramic samples with increased mechanical characteristics due to their high density and low defects. The addition of silicon carbide filamentous crystals or fibers to the ceramics can increase the crack resistance of the sintered material up to 6.0–8.5 MPa×m1/2. These conclusions can be useful in the development of ultra-high-temperature ceramic materials.

Influence of Currents and Electric Fields in YNMO Ceramics

2017 ◽  
Vol 866 ◽  
pp. 256-258
Author(s):  
Naphat Albutt ◽  
Suejit Pechprasarn ◽  
Thanapong Sareein
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Electrical Properties ◽  
Electric Fields ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Solid State Reaction Method ◽  
Electronic Components ◽  
Reaction Method ◽  
A Current

Development of ceramic materials is critical for new and improved electronic applications. Herein, the J-E response of Y2NiMnO6 (YNMO) ceramics composited by a solid state reaction method was investigated. Sintering temperature and time were found to have significant influence on the ceramics electrical properties. In particular, higher temperatures and longer sintering times resulted in more favourable dielectric properties of the YNMO ceramics. A current of 40 mA/cm2 at 20,000 mV/cm was obtained by sintering at 1300 °C for 12 hours, whereas a current of 9 mA/cm2 at 4000 mV/cm can be achieved by sintering at 1400 °C for 24 hours. These results will be useful for identifying applications for YNMO ceramics. The electrical properties of the YNMO ceramics can be tuned for different electronic components such as dry batteries and capacitors.

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