Composition-Microstructure-Property Relationships in BaTiO3 with Mg Addition

2015 ◽  
Vol 659 ◽  
pp. 58-63
Author(s):  
Oratai Jongprateep ◽  
Tunchanoke Khongnakhon ◽  
Jednupong Palomas

Rising worldwide demands for energy encourages development of high-efficiency energy storage and capacitor components. Main requirements for dielectric materials employed in fabrication of high energy density capacitors include high dielectric constant, high dielectric breakdown strength, and low dielectric loss. Owing to its high dielectric constant and low dielectric loss [1], barium titanate is among common capacitor materials. Tailoring of dielectric properties of barium titanate can be achieved through controlled chemical composition, microstructure, and crystal structure. Synthesis and processing techniques, as well as doping of barium titanate, can be key factors to control the composition and structure, which consequently contribute to enhancement of dielectric constant in the material.

2016 ◽  
Vol 840 ◽  
pp. 87-90 ◽  
Author(s):  
Rosyaini Afindi Zaman ◽  
Mohamad Johari Abu ◽  
Saniah Abdul Karim ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
...  

In recent years, there has been an increasing interest on high dielectric constant that have significant applications in electronic devices. Dielectric materials have many technological applications such as capacitors, resonators and filters. High dielectric ceramic capacitors based perovskite oxides are necessary for modern electronic devices and are found to be suitable for a wide range of applications. Subramanian et al. discovered the high dielectric constant of CaCu3Ti4O12 (CCTO) ~ 10,000 at room temperature. CCTO has the cubic perovskite crystal structure and high dielectric constant of ~ 104 up to 105 at radio frequency and good temperature stability over a wide temperature range [1,2]. These properties were desired for various microelectronic applications. With the high dielectric constant, the material can store more charge and the values make CCTO an attractive material for ultra-high energy density capacitors. However, this properties can be accomplished if single phase of CCTO is formed. Many research have been done recently on the synthesis of the cubic perovskite CCTO and many techniques are working such as sol-gel route [3], combustion techniques [4], molten salt process [5] and etc., but this technique is difficult and complex process during sample preparation.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4780
Author(s):  
Yushu Li ◽  
Yao Zhou ◽  
Sang Cheng ◽  
Jun Hu ◽  
Jinliang He ◽  
...  

The development of high-energy-density electrostatic capacitors is critical to addressing the growing electricity need. Currently, the widely studied dielectric materials are polymer nanocomposites incorporated with high-dielectric-constant nanoparticles. However, the introduction of high-dielectric-constant nanoparticles can cause local electric field distortion and high leakage current, which limits the improvement in energy density. In this work, on the basis of conventional polymer nanocomposites containing high-dielectric-constant nanoparticles, oriented boron nitride nanosheets (BNNSs) are introduced as an extra filler phase. By changing the volume ratios of barium titanate (BT) and BNNSs, the dielectric property of polymer nanocomposites is adjusted, and thus the capacitive energy storage performance is optimized. Experimental results prove that the oriented BNNSs can suppress the propagation of charge carriers and decrease the conduction loss. Using poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) as the polymer matrix, the P(VDF-HFP)/BNNS/BT nanocomposite has a higher discharged energy density compared with the conventional nanocomposite with the freely dispersed BT nanoparticles.


2015 ◽  
Vol 1740 ◽  
Author(s):  
Masahiko Ando ◽  
Naoki Yoshimoto ◽  
Yuichiro Yoshitake ◽  
Shuji Kato ◽  
Hidekazu Kodama ◽  
...  

ABSTRACTBased on the investigation of mechanism for large dielectric losses in relaxor fluorinated polymers, polyvinylidene fluoride (PVDF) derivatives, a new nanostructure-controlled PVDF based polymer films with low dielectric loss, tanδ < 1% (0.6%), and high dielectric constant, εr = 13 at frequency of 1 kHz, was proposed for electrical energy storage applications. The high dielectric loss was mainly due to the electric-field induced α-β phase transition, and one dimensional extension of P(VDF-TrFE)-g-PEMA films was found to reduce the α phase component resulting in reduction of the dielectric loss while keeping the high dielectric constant. In-situ FTIR measurements suggested a possibility of further reducing the dielectric-loss.


2018 ◽  
Vol 6 (9) ◽  
pp. 2370-2378 ◽  
Author(s):  
Yang Liu ◽  
Cheng Zhang ◽  
Benyuan Huang ◽  
Xu Wang ◽  
Yulong Li ◽  
...  

A novel skin–core structured fluorinated MWCNT nanofiller was prepared to fabricate epoxy composite with broadband high dielectric constant and low dielectric loss.


2021 ◽  
pp. 095400832199352
Author(s):  
Wei Deng ◽  
Guanguan Ren ◽  
Wenqi Wang ◽  
Weiwei Cui ◽  
Wenjun Luo

Polymer composites with high dielectric constant and thermal stability have shown great potential applications in the fields relating to the energy storage. Herein, core-shell structured polyimide@BaTiO3 (PI@BT) nanoparticles were fabricated via in-situ polymerization of poly(amic acid) (PAA) and the following thermal imidization, then utilized as fillers to prepare PI composites. Increased dielectric constant with suppressed dielectric loss, and enhanced energy density as well as heat resistance were simultaneously realized due to the presence of PI shell between BT nanoparticles and PI matrix. The dielectric constant of PI@BT/PI composites with 55 wt% fillers increased to 15.0 at 100 Hz, while the dielectric loss kept at low value of 0.0034, companied by a high energy density of 1.32 J·cm−3, which was 2.09 times higher than the pristine PI. Moreover, the temperature at 10 wt% weight loss reached 619°C, demonstrating the excellent thermostability of PI@BT/PI composites. In addition, PI@BT/PI composites exhibited improved breakdown strength and toughness as compared with the BT/PI composites due to the well dispersion of PI@BT nanofillers and the improved interfacial interactions between nanofillers and polymer matrix. These results provide useful information for the structural design of high-temperature dielectric materials.


RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23309-23312 ◽  
Author(s):  
Ting Yang ◽  
Wenhui Xu ◽  
Xinwen Peng ◽  
Haoqing Hou

Crown ether-containing polyimides possess high dielectric constant and low dielectric loss, without sacrificing other properties.


2016 ◽  
Vol 34 (2) ◽  
pp. 322-329 ◽  
Author(s):  
Wan Q. Cao ◽  
Ling F. Xu ◽  
Mukhlis M. Ismail ◽  
Li L. Huang

AbstractBaTiO3 ceramics doped with 0.40 mol% NaNbO3 were prepared using a traditional approach by sintering at temperature of 1250 °C to 1290 °C. The prepared ceramics was characterized by very good dielectric properties, such as high dielectric constant (1.5 × 105), low dielectric loss (0.1), and good dielectric temperature stability in the −40 °C to 100 °C range for the sample sintered below 1270 °C. The dielectric characteristics obtained with XPS confirmed that Ti4+ ions remain in the state without any change. The huge increase in dielectric constant in NaNbO3 doped BaTiO3 samples occurs when large amount of Ba2+ ions are excited to a high energy bound state of Ba2+ − e or Ba+ to create electron hopping conduction. For samples with the content of NaNbO3 higher than 0.40 mol%, or sintering temperature higher than 1280 °C, compensation effect is dominated by cation vacancies with sharply decreasing dielectric constant and increased dielectric loss. The polaron effect is used to explain the relevant mechanism of giant dielectric constant appearing in the ferroelectric phase.


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