Sintered compacts of nano and micron-sized BaTiO3: Dramatic influence on the microstructure and dielectric properties

2006 ◽  
Vol 21 (4) ◽  
pp. 816-822 ◽  
Author(s):  
Vishnu Shanker ◽  
Tokeer Ahmad ◽  
Henry Ip ◽  
Ashok K. Ganguli
Keyword(s):  
Differential Scanning Calorimetry ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
High Dielectric Constant ◽  
Scanning Calorimetry ◽  
Ferroelectric Transition ◽  
Maximum Dielectric Constant ◽  
High Dielectric ◽  
First Time

Sintered compacts of nano-sized and micron-sized BaTiO3 show sharp ferroelectric transition and high dielectric constant at specific compositions. The sintered compacts with 1 wt% nano-BaTiO3 show a maximum dielectric constant of 1680. At the transition temperature (Tc) there are two maxima at 0.5 and 2 wt%. The variation in the dielectric constant at Tc is also reflected in the behavior of the ferroelectric transition as studied by differential scanning calorimetry. This interesting oscillatory variation of the dielectric constant and dielectric loss with increase in the amount of nanoparticles in the sintered compacts is observed for the first time. The variation of the dielectric properties and the ferroelectric transition of the sintered compacts could be related to subtle changes in the microstructure.

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.

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.

scholarly journals Enhanced dielectric and ferroelectric properties of surface hydroxylated Na0.5Bi0.5TiO3 (NBT)-poly(vinylidene fluoride) (PVDF) composites

2018 ◽  
Vol 08 (03) ◽  
pp. 1850017 ◽  
Author(s):  
Srikanta Moharana ◽  
Shraddhakara Sai ◽  
Ram Naresh Mahaling
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Material Surface ◽  
Hydroxyl Groups ◽  
Energy Storage Devices ◽  
Surface Hydroxylation ◽  
High Dielectric

The surface hydroxylation treatment has been carried out by using hydrogen peroxide (H2O2) to modify the surface of Na[Formula: see text]Bi[Formula: see text]TiO3 (NBT) particles in a ferroelectric polymer (PVDF) via solution casting technique. The FTIR study confirms the presence of hydroxyl groups on the surface of NBT. The FE-SEM analysis reveals that h-NBT particles are dispersed homogeneously within the polymer matrix. The surface hydroxylation treatment plays an important role in high dielectric constant and also reduced loss by conducting the material surface with [Formula: see text]OH functional groups. The prepared composite with 40[Formula: see text]wt.% of h-NBT showed enhanced dielectric constant ([Formula: see text]114), negligible loss (0.22) and high AC conductivity as compared to that of the unmodified NBT. Such significant enhancement in dielectric properties may be due to the strong interaction between h-NBT particles and PVDF matrix at the interface. The percolation theory is used to explain the dielectric properties of h-NBT-PVDF composite. Furthermore, the remnant polarization of the un-poled h-NBT-PVDF composites (2[Formula: see text]Pr–1.19[Formula: see text][Formula: see text]C/cm2 for 40[Formula: see text]wt.% of h-NBT) is also improved. The present findings give an idea of high dielectric constant and relatively low loss composite materials as a promising candidate for electronic and energy storage devices.

Preparation and Dielectric Properties of Sm3+-Substituted SrBi8Ti7O27 Based Microwave Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 95-98
Author(s):  
Yan Xiang Wang ◽  
C. Fang ◽  
Min Tang ◽  
Hong Qiu ◽  
Zhao Xian Xiong
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
High Dielectric Constant ◽  
Microwave Ceramics ◽  
Reaction Route ◽  
Solid State Reaction Route ◽  
Dta And Tg ◽  
High Dielectric

Sr(Bi1-xSmx)8Ti7O27 ceramics were prepared by Sm2O3-substitution for Bi2O3 through solid-state reaction route. The dielectric properties of the sintered bodies such as er, Q and tf were investigated. The ceramics were characterized by SEM, XRD, DTA and TG, which behaved high dielectric constant of 128 ~154 at the frequency of 10 GHz.

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