Effect of minor phase (CuO) on sinterability, grain size, and dielectric properties of CaCu3Ti4O12 ceramics

Kaur, Taranveer; Punj, S K; Kumar, Rohit; Singh, K.

doi:10.1007/s00339-020-03963-y

Cited by 7 publications

(1 citation statement)

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“…Low permittivity can also be attributed to the fact that the sintering temperature of 1050 • C is insufficient for the formation of insulator grain boundary layer for these Li + concentrations. Such an effect is exhibited presumably owing to the high CuO deficiency on the grain boundaries [42]. Only a small number of Cu ions undergo the oxidation-reduction reaction due to the oxygen vacancies present for the optimal charge balance in case of CCTO ceramics being sintered at elevated temperatures.…”

Section: Resultsmentioning

confidence: 99%

The Effect of Lithium Doping on the Dielectric Properties of Solid Solutions LixCa(1−x)Cu3Ti4O12 (x = 0.01–0.1)

et al. 2023

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In this paper, LixCa(1−x)Cu3Ti4O12 (LCCTO) solid solutions were successfully synthesized. XRD diagrams showed that dopant acceptor Li+ cations, in a concentration range of x = 0.01–0.10, were successfully merged into CCTO structure. It was found that doping with low concentrations of lithium (x < 0.05) inhibited grain growth during annealing; however, for x > 0.05, the grain growth process resumed. Permittivity and dielectric losses of obtained LCCTO ceramics were analyzed by the means of impedance spectroscopy in a frequency range from 10−1 to 106 Hz. It was revealed that acceptor doping with lithium at an appropriate concentration of x = 0.05 allowed to obtain ceramics with a permittivity level of ε′ = 3 × 104 and low dielectric losses tanδ < 0.1 at 1 kHz. Further addition of lithium in a concentration range of x = 0.075–0.10 led to a sharp decline in permittivity and an increase in dielectric losses. It was discovered that lithium addition to CCTO ceramics drastically decreased grain boundary resistivity from 115 MΩ·cm to 5–40 MΩ·cm at x = 0.01–0.10. Using Havriliak–Negami equation, the relaxation times for grain dipoles and grain boundary dipoles were found to be ranging from 0.8 × 10−6 to 1.7 × 10−6 s and from 0.4 × 10−4 to 7.1 × 10−4 s, respectively. The developed materials can be used in the manufacture of Multilayer Ceramic Capacitors (MLCC) as a dielectric.

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Section: Resultsmentioning

confidence: 99%