Study on the synthesis and application of BaTiO3 nanospheres

Author(s):  
Do Viet On ◽  
Le Dai Vuong ◽  
Truong Van Chuong ◽  
Dao Anh Quang ◽  
Vo Thanh Tung

Abstract In the present study, BaTiO3 nanospheres with a uniform particle size of around 100 nm were prepared by a hydrothermal route using Ba(OH)2.8H2O and TiO2 nanoparticles. Experimental results revealed that the main influencing factors for the formation of BaTiO3 nanospheres were molar Ba/Ti ratio (R Ba/Ti), hydrothermal temperature, and time. Highly-dispersed BaTiO3 nanospheres (100 nm) were obtained under the optimum hydrothermal conditions at temperature = 200°C, time = 12 h, and R Ba/Ti = 1.5. Under these optimum conditions, BaTiO3 ceramics were synthesized from the as-prepared BaTiO3 nanospheres, and their structural, microstructural, and electrical properties were investigated. The BaTiO3 ceramics exhibited a high dielectric constant of 7300 at a Curie temperature of 125 °C, great density (ρ), 5.83 g cm–3; large dielectric constant at room temperature er = 3586 and tan d = 0.03, high remanant polarization P r = 10.6 μC cm–2, low coercive field E c = 4.5 kVcm–1.

Author(s):  
Gyuseung Han ◽  
In Won Yeu ◽  
Kun Hee Ye ◽  
Seung-Cheol Lee ◽  
Cheol Seong Hwang ◽  
...  

Through DFT calculations, a Be0.25Mg0.75O superlattice having long apical Be–O bond length is proposed to have a high bandgap (>7.3 eV) and high dielectric constant (∼18) at room temperature and above.


2012 ◽  
Vol 2012 (1) ◽  
pp. 000609-000616
Author(s):  
Beihai Ma ◽  
Manoj Narayanan ◽  
Shanshan Liu ◽  
Sheng Tong ◽  
U. (Balu) Balachandran

Ceramic film capacitors with high dielectric constant and high breakdown strength are promising for use in advanced power electronics, which would offer higher performance, improved reliability, and enhanced volumetric and gravimetric efficiencies. We have grown lead lanthanum zirconate titanate (PLZT) on nickel foils and platinized silicon (PtSi) substrates by chemical solution deposition. A buffer layer of LaNiO3 (LNO) was deposited on the nickel foils prior to the deposition of PLZT. We measured the following electrical properties for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively: remanent polarization, ≈25.4 μC/cm2 and ≈10.1 μC/cm2; coercive electric field, ≈23.8 kV/cm and ≈27.9 kV/cm; dielectric constant at room temperature, ≈1300 and ≈1350; and dielectric loss at room temperature, ≈0.06 and ≈0.05. Weibull analysis determined the mean breakdown strength to be 2.6 MV/cm and 1.5 MV/cm for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively. Residual stress analysis by x-ray diffraction revealed compressive stress of ≈-520 MPa in the ≈2-μm-thick PLZT grown on LNO buffered Ni foil, but a tensile stress of ≈210 MPa in the ≈2-μm-thick PLZT grown on PtSi substrates.


2013 ◽  
Vol 802 ◽  
pp. 134-138 ◽  
Author(s):  
Worawut Makcharoen

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)


2006 ◽  
Vol 949 ◽  
Author(s):  
Xiaobing Shan ◽  
Xin Yang ◽  
Kewei Zhang ◽  
Zhongyang Cheng

ABSTRACTBy using conventional solution casting method, a flexible ceramic [CaCu3Ti4O12 (CCTO)]-Polymer [P(VDF-TrFE)] composite has been fabricated. The CCTO ceramic powders with a relative uniform size were prepared by traditional powder processing method. The dielectric properties of these films with different CCTO fractions were determined. The process was optimized to achieve high dielectric constant. A dielectric constant about 510 at room temperature and 1240 at 95 °C at 1 kHz for 6 layer hot compression was obtained.


2005 ◽  
Vol 20 (11) ◽  
pp. 3011-3020 ◽  
Author(s):  
Chang Houn Rhee ◽  
Jae Sung Lee ◽  
Soo Hyun Chung

Nitrogen-doped titanium oxides nanostructures were synthesized by a new method proposed here from titanium oxysulfate precursor in a NH4OH solution under hydrothermal conditions without any extra templates as structure driving agents. The material synthesized with NH4OH was an ammonium titanate and showed curled nanosheets, nanofibers or nanorods morphologies depending on the molar ratio of NH4OH to titanium precursor and the hydrothermal temperature. The nanofibrous titanates had a high surface area over 500 m2 g−1 and a pore volume of 0.72 cm3 g−1. The calcination of as-synthesized material at 673 K produced a titanium oxynitride TiO2−xNx with anatase phase, which absorbed visible light. Ion exchange of ammonium ion of the titanate with sodium Na2Ti3O7−xNx enhanced the thermal stability of the titanate phase.


2017 ◽  
Vol 866 ◽  
pp. 277-281
Author(s):  
Naphat Albutt ◽  
Suejit Pechprasarn ◽  
Pattaraporn Damkoengsuntorn ◽  
Thanapong Sareein

In this work, the uses of giant dielectric constant of Y2NiMnO6 ceramics were investigated in the frequency range from 1 kHz to 3 MHz. The Y2NiMnO6 ceramics were sintered at 1400 °C for 6, 12, 18 and 24 hours, respectively. The dielectric properties of Y2NiMnO6 ceramics were examined in dc bias from 0 to 1.5 volt at room temperature. We found that all sintering times displayed high dielectric permittivity at frequencies below 105 Hz, above which the values decreased significantly, applied dc bias also reduced dielectric permittivity. The peak of dielectric loss decreased significantly at high dc bias due to decreased contribution of dc conductivity in grain ceramics. This research has characterised electrical properties of Y2NiMnO6 ceramics which maybe suitable for electronic components including batteries and capacitors.


2012 ◽  
Vol 620 ◽  
pp. 230-235 ◽  
Author(s):  
Muhammad Azwadi Sulaiman ◽  
Sabar Derita Hutagalung ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain

CaCu3Ti4O12(CCTO) is a cubical perovskite phase and sintered ceramics exhibit very high dielectric constant at room temperature. The speculated origins of the high dielectric constant are the existence of insulative barrier layer at grain boundaries and domain boundaries which created an internal barrier layer capacitance (IBLC) at the microstructure of CCTO. The relation of grains and domains electrical resistance were studied in this work by using impedance spectroscopy (IS). A series of samples with different heat treatment temperature were tested to investigate their microstructure by using field emission scanning electron microscopy (FESEM). The grains and domains resistance was calculated from a wide frequency range of impedance complex plane measurement (100 Hz to 1 GHz). The FESEM and IS analyses showed the dependency of grains and domains resistance to average grains size of CCTO microstructure.


RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11382-11392 ◽  
Author(s):  
Neeraj Singh ◽  
Preetam Singh

Cu+ ion substituted ZnO, Zn1−xCuxO1−δ have shown high dielectric constant (∼6300) at 600 °C at 100 kHz frequency and ferroelectricity at room temperature than for bulk Zn0.95Cu0.05O1−δ samples.


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