Raman spectroscopy of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">CaCu</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ti</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>12</mml:mn></mml:mrow></mml:msub

Kolev, Nikolay Ivanov; Bontchev, Ranko P.; Jacobson, Allan J.; Popov, V. N.; Hadjiev, V. G.; Litvinchuk, A. P.; Iliev, M. N.

doi:10.1103/physrevb.66.132102

Cited by 156 publications

(79 citation statements)

References 5 publications

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“…All the prominent Raman modes Ag(1)$448 cm À1 , Ag(2)$517 cm À1 , Fg (2)$448 cm À1 , Fg(3)$581 cm À1 corresponding to CCTO ceramics were detected respectively. The detected Raman modes are in agreement with earlier reports, 17,19 however, there is a little shift in the mode positions with respect to the reported data. The presence of Raman modes -Ag(1), Ag (2) and Fg(2) -was attributed due to TiO 6 rotation-like lattice vibrations, whereas the other mode Fg(3) is associated with a O-Ti-O anti-stretching vibration.…”

Section: Raman Spectroscopysupporting

confidence: 82%

Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

et al. 2017

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This paper reports on synthesis of polycrystalline complex perovskite CaCu 3 Ti 4 O 12 (as CCTO) ceramic powders prepared by a solgel auto combustion method at different sintering temperatures and sintering times, respectively. The effect of sintering time on the structure, morphology, dielectric and electrical properties of CCTO ceramics is investigated. Tuning the electrical properties via different sintering times is demonstrated for ceramic samples. X-ray diffraction (XRD) studies confirm perovskite-like structure at room temperature. Abnormal grain growth is observed for ceramic samples. Giant dielectric permittivity was realized for CCTO ceramics. High dielectric permittivity was attributed to the internal barrier layer capacitance (IBLC) model associated with the Maxwell-Wagner (MW) polarization mechanism.

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Section: Raman Spectroscopysupporting

confidence: 82%

Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

et al. 2017

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“…2. These peaks are compared with the theoretical values from the lattice dynamics calculations (LDC) by Kolev et al [24][25][26] and with the experimental values as shown in Table-2. The LDC calculations have predicted eight peaks The sharp peak located at 309 cm -1 is associated to the E(TO+LO) mode and present the characteristic peak of tetragonal BaTiO3 phase.…”

Section: X-ray Diffraction Analysismentioning

confidence: 99%

“…This increase can be explained on the basis of the ability of dipoles to align orientation. Furthermore, at higher temperature the accumulation of charge carrier increases at the interface between grain and grain boundary [24].…”

Section: X-ray Diffraction Analysismentioning

confidence: 99%

Structural, Dielectric and Electrical Properties of (1-x)CaCu3Ti4O12−xBaTiO3 Ceramics

Hadi¹,

Lamcharfi²,

Abdi³

et al. 2017

Asian J. Chem.

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In this work, the effect of BaTiO3 (BT) addition on structural, dielectric and electrical properties of CaCu3Ti4O12 (CCTO) ceramic was investigated. Ceramic samples with the chemical formula (1-x)CaCu3Ti4O12 -xBaTiO3, (1-x)CCTO-xBT, (x = 0.00, 0.10, 0.20, 0.30, 0.50 and 1.00) were synthesized by solid state route. The structural studies carried out by X-ray diffraction technique and showed that the perovskite structure cubic and tetragonal phases were formed without any other impurity phases. The addition of BaTiO3 into CCTO system lowered the last crystallite size to about 52 nm and increased the dielectric constant by four orders compared to pure CCTO. Moreover, the results of the complex impedance analyses of (1-x)CCTO-xBT ceramics samples confirmed the presence of non-Debye type of relaxation phenomenon and exhibited a negative temperature coefficient of resistance behaviour.Keywords: Ceramics, Barium titanate, Raman spectroscopy. Chemistry; Vol. 29, No. 8 (2017), 1811-1816 a mixture CCTO and BaTiO3 characteristics. In the present work we are reporting the synthesis of (1-x)CCTO-xBT by solid state reaction route. The structural, dielectric and electrical properties of (1-x)CaCu3Ti4O12-xBaTiO3 ceramics (where x = 0.00-1.00) were investigated. Asian Journal of EXPERIMENTALThe (1-x)CCTO-(x)BT samples were synthesized by means of a conventional mixed oxide route. High-purity oxides and carbonates; CaCO 3 (99.8 %) CuO (purity, 99 %), TiO 2 (purity, 99.95 %) and BaCO 3 (purity 99.5 %) (All Sigma Aldrich chemicals, USA) were used as starting materials.Synthesis of (1-x)CaCu 3 Ti 4 O 12− − − − −xBaTiO 3 : The powders were weighed in stoichiometric proportion and milled for 1 h. Then the slurry was dried in an oven at 80 °C. The calcinations processes of CCTO and BaTiO 3 powders were carried at 1050°Cand 1100 °C for 4 h, respectively. The synthesized powders were mixed in acetone according to the formula (1-x)CCTO-(x)BT for 2 h and dried at 400 °C for 1 h, after that the powders were crushed in agate mortar and pressed into pellets of about 12 mm diameter and 1.5 mm thickness. Then, the pellets sintered at 1050°C for 8 h and left at room temperature. The samples surfaces were coated by silver paste to serve as poles for the electrical measurements uses. Characterization of (1-x)CaCu3Ti4O12− − − − −xBaTiO3XRD analysis: The crystal structure of (1-x)CCTO-xBT was determined by using an X-ray diffractometer with a scanning rate of 0.02°/min for 2θ range 20°-80° by employing CuKα radiation wavelength λ = 1.5406 Å (diffractometer system = XPERT-PRO) under the conditions of 40 KV and 30 mA.Raman spectroscopy analysis: A micro Raman spectrometer, equipped with an excitation source of monochromatic with wavelength of 410 nm, was used to study the relationship between Raman lines and different types of atomic motions of CCTO and BaTiO3 in the (1-x)CCTO-xBT ceramics. After the sample processing, Raman spectra was collected at room temperature.Dielectric measurements analysis: The electrical properties of the ceramics were measu...

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“…However, the idea that locally interrupted bracing due to these defects would allow for local distortions involving TiO 6 units to take place is inconsistent with the PDF results, and also the results of recent polarized Raman study on single-crystal CCTO and within broad temperature range. 33 Therefore, local octahedral tilting distortions can be clearly ruled out as a candidate for the observed large dielectric constant.…”

Section: Local Structure and Braced Lattice Modelmentioning

confidence: 99%

Temperature dependent total scattering structural study of CaCu₃Ti₄O₁₂

Božin¹,

Petkov²,

Barnes³

et al. 2004

J. Phys.: Condens. Matter

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X-ray and neutron powder diffraction data as a function of temperature are analyzed for the colossal dielectric constant material CaCu3Ti4O12. The local structure is studied using atomic pair distribution function analysis. No evidence is found for enhanced oxygen displacement parameters suggesting that short-range octahedral tilt disorder is minimal. However, an unusual temperature dependence for the atomic displacement parameters of calcium and copper is observed. Temperature dependent modeling of the structure, using bond valence concepts, suggests that the calcium atoms become underbonded below approximately 260 K, which provides a rationale for the unusually high Ca displacement parameters at low temperature.

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Raman spectroscopy ofCaCu3Ti4O12

Cited by 156 publications

References 5 publications

Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

Structural, Dielectric and Electrical Properties of (1-x)CaCu3Ti4O12−xBaTiO3 Ceramics

Temperature dependent total scattering structural study of CaCu₃Ti₄O₁₂

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Raman spectroscopy ofCaCu3Ti4O12

Cited by 156 publications

References 5 publications

Low temperature sintered giant dielectric permittivity CaCu3Ti4O12 sol-gel synthesized nanoparticle capacitors

Low temperature sintered giant dielectric permittivity CaCu3Ti4O12 sol-gel synthesized nanoparticle capacitors

Structural, Dielectric and Electrical Properties of (1-x)CaCu3Ti4O12−xBaTiO3 Ceramics

Temperature dependent total scattering structural study of CaCu3Ti4O12

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Product

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Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

Low temperature sintered giant dielectric permittivity CaCu₃Ti₄O12 sol-gel synthesized nanoparticle capacitors

Temperature dependent total scattering structural study of CaCu₃Ti₄O₁₂