Synthesis of nanoparticles of the giant dielectric material, CaCu3Ti4O12 from a precursor route

Thomas, P.; Dwarakanath, K. S.; Varma, K. B. R.; Kutty, T.R.N.

doi:10.1007/s10973-007-8981-z

Cited by 55 publications

(33 citation statements)

References 20 publications

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“…A characteristic microstructure of CCTO having semiconducting grains and insulating grain boundaries have been grown by various synthesis routes and processing conditions [1,[13][14][15][16]. Microstructure of these ceramics strongly depends on the sintering conditions such as rate of heating, hold time and sintering temperature.…”

Section: Introductionmentioning

confidence: 99%

Structural and impedance spectroscopic studies of spark plasma sintered CaCu3Ti4O12 dielectric ceramics: an evidence of internal resistive barrier effect

Kumar

Zulfequar

Senguttuvan

2016

J Mater Sci: Mater Electron

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A giant dielectric constant CaCu 3 Ti 4 O 12 ceramic was prepared by solid-state reaction route. Powders were spark plasma sintered at 1050°C for 30 min. Rietveld refined XRD pattern reveals the formation of pure phase cubic perovskite CCTO. The dielectric properties were characterized in a broad frequency range of 10 Hz-8 MHz at temperatures 20-120°C. The grain size of sintered pellets was found in range of 12-15 lm. Impedance spectroscopic analysis shows that the observed semicircle in the Cole-Cole plot was associated with grain boundary relaxation effect. This study reveals that there is an evidence of internal resistive barrier which responsible for a giant dielectric constant in CaCu 3 Ti 4 O 12 ceramic. An Arrhenius temperature dependent relaxation effect was observed in grain boundary. Using the characteristic frequency of relaxation peak, grain boundary capacitance was calculated to be 0.27 lF. It was found that on increasing the temperature, the resistance of grain boundaries was decreased rapidly as compared to that of the grains. The activation energy of grain boundary was calculated to be 0.165 eV.

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Section: Introductionmentioning

confidence: 99%

Structural and impedance spectroscopic studies of spark plasma sintered CaCu3Ti4O12 dielectric ceramics: an evidence of internal resistive barrier effect

Kumar

Zulfequar

Senguttuvan

2016

J Mater Sci: Mater Electron

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“…12 The most widely used dielectric ceramics for the development of high permittivity ceramic-polymer composites are those based on BaTiO 3 (BT), BaSrTiO 3 (BST), Pb(Mg 1=3 Nb 2=3 ÞO 3 -PbTiO 3 (PMNPT), Pb (Zr,Ti)O 3 (PZT) and CaCu 3 Ti 4 O 12 (CCTO). [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The double perovskite have attracted considerable attention due to their unique electrical and magnetic properties. They exhibit interesting combination of conductivity, dielectric and magnetic properties depending on the degree of octahedral tilting that changes the extent of orbital overlap between the B-site octahedral networks.…”

Section: Introductionmentioning

confidence: 99%

Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

et al. 2015

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Composites of poly(methyl methacrylate) (PMMA) and Sr 2 TiMnO 6 (STMO) were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), thermo mechanical analysis (TMA) and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE) was measured between 40 C and 100 C for pure PMMA is 115.2 ppm/ C, which was decreased to 78.58 ppm/ C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition (T g ) temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMAþSTMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.

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“…To date, synthesis of CCTO has been performed by either mixed oxides [1][2][3]7], chemical [4,[9][10][11], or mechanical routes [12]. CCTO ceramics are most often produced through conventional mixed oxide methods.…”

Section: Introductionmentioning

confidence: 99%

“…However, this process has a tendency to produce coarse particles with compositional inhomogeneity in addition to the formation of particle agglomerates/aggregates in the resulting powder. Consequently, the sinterability of the powders is considerably reduced [9][10][11]13,14]. Furthermore, it should be noted that in order to achieve the desired CCTO phase, calcination at elevated temperatures is crucial [4,9].…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, the sinterability of the powders is considerably reduced [9][10][11]13,14]. Furthermore, it should be noted that in order to achieve the desired CCTO phase, calcination at elevated temperatures is crucial [4,9]. In spite of the suitable properties achieved through this method [4], broader application of chemical synthesis is also limited due to high precursor costs.…”

Section: Introductionmentioning

confidence: 99%

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Structural and phase evolution in mechanically alloyed calcium copper titanate dielectrics

Alizadeh

Ardakani

Amini

et al. 2013

Ceramics International

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Nanocrystalline calcium-copper-titanate (CCTO) dielectric powders were prepared by mechanical alloying. Phase transformations and structural evolution of the mechanically activated powders were investigated through the Rietveld refinement of the X-ray diffraction results. The crystallite size, lattice strain, and weight fraction of individual phases were estimated based on crystal structure refinement. Furthermore, the microstructural properties and thermal behavior of the milled powders were investigated by Transmission Electron Microscopy (TEM) and Differential Thermal Analysis (DTA), respectively. It was found that CCTO nanocrystals can be successfully synthesized after the amorphization of the initial crystalline materials. Semi-spherical nano-size particles were developed after sufficient milling time. Formation of an amorphous phase during the milling cycle was confirmed by the presence of the glass transition and crystallization peaks in the thermal analysis profiles.

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Synthesis of nanoparticles of the giant dielectric material, CaCu3Ti4O12 from a precursor route

Cited by 55 publications

References 20 publications

Structural and impedance spectroscopic studies of spark plasma sintered CaCu3Ti4O12 dielectric ceramics: an evidence of internal resistive barrier effect

Structural and impedance spectroscopic studies of spark plasma sintered CaCu3Ti4O12 dielectric ceramics: an evidence of internal resistive barrier effect

Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

Structural and phase evolution in mechanically alloyed calcium copper titanate dielectrics

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