Microstructural, dielectric, and nonlinear properties of Ca1–xCdxCu3Ti4O12 thin films. Issue 1 (1st January 2023)

• Record Type: Journal Article
• Authors: Xue, Renzhong; Zhao, Liuyang; Chen, Siyuan; Chen, Hongxuan; Cui, Mengru; Bai, Xintao; Li, Tao; Liu, Dewei; Dai, Haiyang
• Is Part Of: Ceramics international. Volume 49:Issue 1(2023)
• Page Start: 134
• Page End: 144
• Publication Date: 2023-01-01
• Subjects: CaCu3Ti4O12 thin film -- Substitution -- Dielectric properties -- Sol–gel method; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.08.321
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The effects of the A-site transition from Ca 2+ to Cd 2+ on the microstructure, morphology, and electrical properties of Ca1–x Cdx Cu3 Ti4 O12 thin films were studied. The film surfaces are smooth, compact, and without cracks. The CaCu3 Ti4 O12 and CdCu3 Ti4 O12 films had similar morphologies and electrical properties. The grain size initially increased and subsequently decreased with the transition from Ca 2+ to Cd 2+ at the A site. The change in Ca sites has an obvious effect on Cu sites. The film with more copper-rich phases at the grain boundaries had the largest grain size when Ca 2+ and Cd 2+ equally occupied the A sites. The dielectric constant of Ca1–x Cdx Cu3 Ti4 O12 was closely related to the copper oxide secondary phase. The dielectric loss tangent and nonlinearity coefficient were associated with the compact structure, copper oxide secondary phase, copper vacancies and improved grain boundary response. The simultaneous occupancy of the A sites by Ca 2+ and Cd 2+ improves the dielectric and nonlinear properties of Ca1–x Cdx Cu3 Ti4 O12 . Optimal dielectric properties (Ɛr = 5238 and tan δ = 0.009 at 1 kHz) and an enhanced nonlinearity coefficient (∼4.22) were simultaneously obtained for the Ca0.5 Cd0.5 Cu3 Ti4 O12 thin film. This study demonstrates that the extrinsic mechanism is the main origin of the high dielectric constant values in Ca1–x Cdx Cu3 Ti4 O12 films. The resulting films are suitable for applications in capacitors.