Dielectric properties of bismuth doped CaCu3Ti4O12 ceramics

Liang, Xu; Qi, Peng; Chen, S.S.; Wang, R.L.; Yang, Chuang

doi:10.1016/j.mseb.2012.02.001

Cited by 27 publications

(6 citation statements)

References 22 publications

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“…13 15,16 although the relative dielectric permittivity remained greater than 10 4 , the observed dielectric losses (>0.15) were still excessive. Other dopants [17][18][19][20][21][22][23][24] of Zn, Bi, Mg, Zr, Co, Fe, Nb and rare-earth ions also significantly influenced the dielectric response of CCTO ceramics, supporting the hypothesis that the effects of impurities govern the dielectric response of CCTO ceramics. Collectively, the works cited in our literature survey indicate that cationic substitution doping at Cu and/or Ti sites is an effective method for enhancing the performance of CCTO ceramics through the design of the structure and chemical composition of the interfaces at the GBs.…”

Section: Introductionmentioning

confidence: 74%

Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

Wang

Deng

et al. 2017

J Am Ceram Soc

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The improved dielectric properties and voltage‐current nonlinearity of nickel‐doped CaCu3Ti4O12 (CCNTO) ceramics prepared by solid‐state reaction were investigated. The approach of A′‐site Ni doping resulted in improved dielectric properties in the CaCu3Ti4O12 (CCTO) system, with a dielectric constant ε′≈1.51×105 and dielectric loss tanδ≈0.051 found for the sample with a Ni doping of 20% (CCNTO20) at room temperature and 1 kHz. The X‐ray photoelectron spectroscopy (XPS) analysis of the CCTO and the specimen with a Ni doping of 25% (CCNTO25) verified the co‐existence of Cu+/Cu2+ and Ti3+/Ti4+. A steady increase in ε′(f) and a slight increase in α observed upon initial Ni doping were ascribed to a more Cu‐rich phase in the intergranular phase caused by the Ni substitution in the grains. The low‐frequency relaxation leading to a distinct enhancement in ε′(f) beginning with CCNTO25 was confirmed to be a Maxwell‐Wagner‐type relaxation strongly affected by the Ni‐related phase with the formation of a core‐shell structure. The decrease of the dielectric loss was associated with the promoted densification of CCNTO and the increase of Cu vacancies, due to Ni doping on the Cu sites. In addition, the Ni dopant had a certain effect on tuning the current‐voltage characteristics of the CCTO ceramics. The present A′‐site Ni doping experiments demonstrate the extrinsic effect underlying the giant dielectric constant and provides a promising approach for developing practical applications.

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Section: Introductionmentioning

confidence: 74%

Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

Wang

Deng

et al. 2017

J Am Ceram Soc

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“…The dielectric permittivity of the CCTO changes with the modification of the grain size . According to the widely accepted internal barrier layer capacitance (IBLC) model, the larger grains size create the greater number of crystal defects than smaller ones, which allows for more internal barrier layers and leads to an increase in the dielectric constant . The dielectric behavior can be divided into two regions for all the ceramics.…”

Section: Resultsmentioning

confidence: 99%

“…43,44 According to the widely accepted internal barrier layer capacitance (IBLC) model, the larger grains size create the greater number of crystal defects than smaller ones, which allows for more internal barrier layers and leads to an increase in the dielectric constant. 45,46 The dielectric behavior can be divided into two regions for all the ceramics. In the temperature region (<400 K), the dependence of e r on both the frequency and temperature is very weak, and whereas at the higher temperature region (>400 K), e r shows the increasing trend for CCTWO01, CCTWO3 than the CCTWO05 with strong frequency dispersion and temperature dependence.…”

Section: Resultsmentioning

confidence: 99%

A Novel One‐Step Flame Synthesis Method for Tungsten‐Doped CCTO

et al. 2015

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An efficient synthesis is used for the first time to prepare CaCu3Ti4−xWxO12 (x = 0.01, 0.03, and 0.05) electroceramics for energy storage capacitors. CaCu3Ti4−xWxO12 ceramics are synthesized via flame synthesis of metal nitrates precursors in nonaqueous solution using cheap, stable, and insoluble solid TiO2 powder. The pathway yielded a CaCu3Ti4O12 (CCTO) phase with the traces of CuO and CaTiO3 sintered at 1050°C for 30 h. The SEM micrograph shows the grains with smooth surfaces associated with cubical appearance and the size range of 1.5–7, 2.0–7.5, and 2.0–8.0 μm for CCTWO01, CCTWO03, and CCTWO05, respectively. The EDX and XPS analyses show the presence of Ca, Cu, Ti, W, and O elements confirming the purity of these ceramics. The complex impedance and modulus (M) spectroscopy show that the dielectric constant (εr) values of the W‐doped CCTO were dominantly affected by the electrical properties of the grain boundary, which is also evident from the SEM micrographs. The grain‐boundary resistance decreased with increasing tungsten content. The activation energies for the grain boundaries were calculated from the impedance and modulus data using the slope of the ln τ versus 1/T and were found to be in the range 0.62–0.67 eV.

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“…A greater number of crystal defects are able to exist in larger grains than in smaller ones. This allows for more internal barrier layers [29]. The dielectric permittivity in CCTO strongly depends on the grain size, and an increase of the grain size leads to an increase of the dielectric permittivity.…”

Section: Fe-semmentioning

confidence: 99%

Microstructural and Dielectric Properties of Zr Doped Microwave SinteredCaCu3Ti4
Jesurani
¹
,
Kanagesan
²
,
Hashim
³

et al. 2014
Advances in Materials Science and Engineering
5
0
4
0
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Polycrystalline samples with the chemical formula CaCu 3 Ti 4−x Zr x O 12 ( = 0, 0.02, 0.1, 0.2, 0.5, and 0.1) CCTZO were synthesized from metal nitrate solutions by the sol-gel method, followed by conventional and microwave heat treatments. The X-ray diffraction pattern of powder calcined at 800 ∘ C in conventional furnace for 3 h showed formation of a single phase. The crystal structure did not change on doping with zirconium and it remained cubic in the five studied compositions. The surface morphology of samples sintered at 1000 ∘ C in microwave furnace for 10 min was observed using a high resolution scanning electron microscope (HR-SEM). The grain sizes were in the range of 250 nm-5 m for these samples. HRSEM results show that doping with Zr enhanced grain growth or densification. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Zr. The dielectric characteristics of Zr doped CCTO were studied with an LCR meter in the frequency range of 50 Hz-1 MHz. A very high dielectric constant 21,500 was observed for the sample doped with Zr (0.02 mol%) at 50 Hz.

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Dielectric properties of bismuth doped CaCu3Ti4O12 ceramics

Cited by 27 publications

References 22 publications

Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

A Novel One‐Step Flame Synthesis Method for Tungsten‐Doped CCTO

Microstructural and Dielectric Properties of Zr Doped Microwave SinteredCaCu3Ti4
Jesurani
¹
,
Kanagesan
²
,
Hashim
³

et al. 2014
Advances in Materials Science and Engineering
5
0
4
0
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Dielectric properties of bismuth doped CaCu3Ti4O12 ceramics

Cited by 27 publications

References 22 publications

Improved dielectric properties in A′‐site nickel‐doped CaCu3Ti4O12 ceramics

Improved dielectric properties in A′‐site nickel‐doped CaCu3Ti4O12 ceramics

A Novel One‐Step Flame Synthesis Method for Tungsten‐Doped CCTO

Microstructural and Dielectric Properties of Zr Doped Microwave SinteredCaCu3Ti4Jesurani1, Kanagesan2, Hashim3 et al. 2014Advances in Materials Science and Engineering5040View full textAdd to dashboardCite

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Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

Improved dielectric properties in A′‐site nickel‐doped CaCu₃Ti₄O₁₂ ceramics

Microstructural and Dielectric Properties of Zr Doped Microwave SinteredCaCu3Ti4
Jesurani
¹
,
Kanagesan
²
,
Hashim
³

et al. 2014
Advances in Materials Science and Engineering
5
0
4
0
View full text Add to dashboard Cite