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Reducing Dielectric Loss in CaCu3Ti4O12 Ceramics by Spark Plasma Sintering-Enabled Control of Grain-Boundary Potential Barriers
Zhisong Zhou, Jingdong Chen, Xiaogang Wang, Bo He, Qing Ma, Wenyan Wang
PetroChina Southwest Oil&Gasfield Company, No.8, Section 4, Huayang Avenue, Shuangliu District, Chengdu City, Sichuan Province, 610213, China
received February 15, 2026, received in revised form April 14, 2026, accepted April 19, 2026
Pages 1-12 DOI: 10.4416/JCST2026-00003
Abstract
CaCu3Ti4O12 (CCTO) ceramics exhibit a giant dielectric constant but often suffer from high dielectric loss that limits their practical use. In this work, Spark Plasma Sintering (SPS) was employed as a rapid, interface-aware densification route to regulate the microstructure and electrical response of CCTO without chemical doping. Dense ceramics were fabricated at 1 000 °C under 50 MPa with holding times of 5 – 30 min and compared with a conventionally sintered reference prepared at 1 100 °C for 12 h. The SPS samples showed finer and more homogeneous grains, reduced secondary-phase signatures, much lower dielectric loss, and a markedly stronger grain-boundary resistive response. The SPS-10 sample delivered ε′ ≈ 2.9 × 104 and tan δ = 0.022 at 1 kHz at room temperature. Impedance and nonlinear J-E analyses indicate that the superior dielectric behavior is consistent with more effective grain-boundary barriers in the SPS ceramics. Fracture-surface XPS is interpreted here only as supportive near-surface chemical information, rather than as direct proof of grain-boundary-specific defect chemistry. These results show that SPS can substantially suppress dielectric loss in CCTO by coordinating densification, microstructural refinement, and interfacial electrical response.
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Keywords
Internal barrier layer capacitor, grain-boundary engineering, Schottky barrier, impedance spectroscopy, nonlinear current-voltage behavior
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