Improved dielectric properties in CaCu3Ti4O12 ceramics modified by TiO2

Wang, X. W.; Jia, Pengbo; Sun, Li; Zhang, B. H.; Hu, Yidan; Shang, Jun; Zhang, Y. Y.

doi:10.1007/s10854-017-8139-0

Cited by 10 publications

(2 citation statements)

References 31 publications

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“…The giant dielectric properties (GDPs) of dielectric materials with a high dielectric constant () have been extensively studied for use in electronics applications, such as capacitive devices used in high-energy storage devices [1][2][3][4][5][6][7][8][9][10][11][12][13]. Most recently, giant dielectric materials have been proposed as potential epsilon-negative or mu-negative materials [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

“…Most recently, giant dielectric materials have been proposed as potential epsilon-negative or mu-negative materials [14][15][16]. High  values of 10 3 10 5 in the low-frequency range without detectable phase transitions have been reported for a wide range of functional electroceramics, such as doped TiO 2 [4,17], doped SnO 2 [18], doped NiO [19], CaCu 3 Ti 4 O 12 (CCTO) and its related structures [3,5,[20][21][22][23], and La 2−x Sr x NiO 4 [24]. These ceramic oxides can be used in electronic devices, such as capacitors, sensors, and varistors.…”

Section: Introductionmentioning

confidence: 99%

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Enhanced giant dielectric properties and improved nonlinear electrical response in acceptor-donor (Al3+, Ta5+)-substituted CaCu3Ti4O12 ceramics

et al. 2021

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The giant dielectric behavior of CaCu3Ti4O12 (CCTO) has been widely investigated owing to its potential applications in electronics; however, the loss tangent (tanδ) of this material is too large for many applications. A partial substitution of CCTO ceramics with either Al3+ or Ta5+ ions generally results in poorer nonlinear properties and an associated increase in tanδ (to ∼0.29–1.15). However, first-principles calculations showed that self-charge compensation occurs between these two dopant ions when co-doped into Ti4+ sites, which can improve the electrical properties of the grain boundary (GB). Surprisingly, in this study, a greatly enhanced breakdown electric field (∼200–6588 V/cm) and nonlinear coefficient (∼4.8–15.2) with a significantly reduced tanδ (∼0.010–0.036) were obtained by simultaneous partial substitution of CCTO with acceptor-donor (Al3+, Ta5+) dopants to produce (Al3+, Ta5+)-CCTO ceramics. The reduced tanδ and improved nonlinear properties were attributed to the synergistic effects of the co-dopants in the doped CCTO structure. The significant reduction in the mean grain size of the (Al3+, Ta5+)-CCTO ceramics compared to pure CCTO was mainly because of the Ta5+ ions. Accordingly, the increased GB density due to the reduced grain size and the larger Schottky barrier height (Φb) at the GBs of the co-doped CCTO ceramics were the main reasons for the greatly increased GB resistance, improved nonlinear properties, and reduced tanδ values compared to pure and single-doped CCTO. In addition, high dielectric constant values (ε′ ≈ (0.52–2.7) × 104) were obtained. A fine-grained microstructure with highly insulating GBs was obtained by Ta5+ doping, while co-doping with Ta5+ and Al3+ resulted in a high Φb. The obtained results are expected to provide useful guidelines for developing new giant dielectric ceramics with excellent dielectric properties.

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