Influence of Li Addition on the Sintering and Dielectric Properties of PNN-PMW-PT Relaxor Ferroelectrics

1996 ◽  
Vol 453 ◽  
Author(s):  
Raghu Natarajan ◽  
Joseph P. Dougherty
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Low Temperature ◽  
High Dielectric Constant ◽  
Sintering Temperature ◽  
Relaxor Ferroelectrics ◽  
High Dielectric ◽  
And Shifts ◽  
Electrode Systems

AbstractCompositions in the PNN-PMW-PT system can be tailored to give high dielectric constant for MLC applications. Low temperature firing of MLC is always advantageous in using the less expensive electrode systems. Controlled addition of LiNO3 reduces the sintering temperature, increases the fired density and influences the microstructure of the ceramics. It also raises the peak dielectric constant and shifts the Curie temperature. The possible role of Li+ in modifying the characteristics of the ceramics is discussed.

Low Temperature Sintering Ba3Ti5Nb6O28 Ceramics with Tunable Temperature Coefficient of Dielectric Constant

2008 ◽  
Vol 368-372 ◽  
pp. 170-172 ◽  
Author(s):  
Dong Guo ◽  
Zhi Yuan Ling ◽  
Xing Hu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Low Temperature ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Low Temperature Sintering

A middle permittivity dielectrics with the tunable temperature coefficient of dielectric constant (τε) in the BaO-TiO2-Nb2O5 system, Ba3Ti5Nb6O28, has been synthesized and characterized. The dielectric properties of Ba3Ti5Nb6O28 measured at 1MHz are as follows: dielectric constant (εr) ~38, dielectric loss (tanδ)<0.0002, temperature coefficient of dielectric constant (τε)~-22ppm/°C. The Ba3Ti5Nb6O28 phase satisfies the requirements of NP0 (MLCC) dielectrics, but the sintering temperature of the Ba3Ti5Nb6O28 phase (1250~1300°C) is too high to be co-fired with Ag or Cu electrodes. To lower the sintering temperature, an appropriate amount of ZnO-B2O3 frit (5~7wt.%) was added to the Ba3Ti5Nb6O28 phase and dense ceramics were obtained at the sintering temperature lower than 1000°C. Furthermore, the CaNb2O6 phase with the positive τε of 65ppm/°C was incorporated into the Ba3Ti5Nb6O28 phase to adjust the temperature coefficient of dielectric constant from negative to positive(-22~30ppm/°C). Near zero τε ceramics with high εr (38) and low tanδ (0.0002) were obtained at the composition of Ba3Ti5Nb6O28/ CaNb2O6/ ZB frit=76:17:7 wt.%.

Preparation, Morphology and Dielectric Properties of Polyamide-6/Poly(Vinylidene Fluoride) Blends

2012 ◽  
Vol 496 ◽  
pp. 263-267
Author(s):  
Rui Li ◽  
Jian Zhong Pei ◽  
Yan Wei Li ◽  
Xin Shi ◽  
Qun Le Du
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Flexible Electronics ◽  
High Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Volume Fraction ◽  
Polyamide 6 ◽  
Dielectric Constants ◽  
Poly Vinylidene Fluoride ◽  
High Dielectric

A novel all-polymeric material with high dielectric constant (k) has been developed by blending poly (vinylidene fluoride) (PVDF) with polyamide-6 (PA6). The dependence of the dielectric properties on frequency and polymer volume fraction was investigated. When the volume fraction of PA6 is 20%, the dielectric property is better than others. The SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial interactions of polymer-polymer. The XRD demonstrate that the PA6 and PVDF affect the crystalline behavior of each component. Furthermore, the stable dielectric constants of the blends could be tuned by adjusting the content of the polymers. The created high-k all-polymeric blends represent a novel type of material that are simple technology and easy to process, and is of relatively high dielectric constant, applications as flexible electronics.

Low Temperature Sintering of Lead-Free BaTiO3-Based X9R Ceramics with Bi2O3 Dopant and Assisted by LiF-CaF2 Flux Agent

2014 ◽  
Vol 906 ◽  
pp. 31-36 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jun Zhang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Temperature Stability ◽  
Lead Free ◽  
Low Temperature Sintering ◽  
Pure Silver ◽  
Flux Agent ◽  
Low Sintering Temperature

The sintering temperature of BaTiO3powder was reduced to 950°C due to the Bi2O3-LiF-CaF2addition.Excellent densification was achieved after sintering at 950°C for 10h. The low sintering temperature of newly developed capacitor materials allows a co-firing with pure silver electrodes.The dielectric constant and the temperature stability of the dielectric constant satisfied the X9R standard, which dielectric properties of were ε25°C1115, ΔC/C25°C±12% (55~200°C), tanδ1.5% (25°C).

Effect of Platinum Substitution on the Microstructures and Dielectric Relaxation of CaCu3Ti4O12 Ceramics

2013 ◽  
Vol 802 ◽  
pp. 134-138 ◽  
Author(s):  
Worawut Makcharoen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Tangent ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Materials ◽  
X Ray Diffraction ◽  
High Loss ◽  
Internal Barrier Layer Capacitor ◽  
High Dielectric

The CaCu3Ti4O12(CCTO) has the advantage for the various applications especially for capacitive elements in microelectronic devices over the ferroelectric materials including BaTiO3. CCTO is a ceramic compound with a high dielectric constant but it has a high loss tangent at room temperature. In this work, the Influences of PtO2doping on the dielectric properties of CaCu3Ti4O12(CCTO) ceramics were investigate. The ceramics CCTO and PtO2doping CCTO were studied by X- ray diffraction, scanning electron microscopy. The dielectric properties have been measured as a function of temperature and frequency range 0.1 - 500 kHz. The XRD shows the CCTO structure does not changes after doping with platinum. The results show that PtO2doped can reduce the mean grain sizes of CCTO, but the dielectric constant still remained a height. The samples of 2.0 mol% Pt-doped have exhibited high dielectric constant of about 22,000 and the loss tangent about 0.7 at room temperature and frequency at 10 kHz. The reduced of the loss tangent could be interpreted with the internal barrier layer capacitor model (IBLC)

Processing and the Microstructure of SrTiO3-Based Bl Capacitors using Pb(Fe, W)O3 Ferroelectrics

1989 ◽  
Vol 155 ◽  
Author(s):  
Makoto Kuwabara
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Grain Boundaries ◽  
Strontium Titanate ◽  
Barrier Layer ◽  
High Dielectric Constant ◽  
Ferroelectric Materials ◽  
New Type ◽  
High Dielectric ◽  
Very High

ABSTRACTA preliminary experiment was conducted to prepare semiconducting strontium titanate-based internal barrier layer capacitors with ferroelectric Pb(Fe, W)O3 forming insulating layers along the grain boundaries. Processing, microstructure and the dielectric properties of this new type of BL capacitors are described. The idea to obtain this type of BL capacitors with a very high dielectric constant may be realized when the ferroelectric materials can uniformly be diffused along the grain boundaries by using a more sophisticated processing of the second firing.

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