Significantly improving the giant dielectric properties of CaCu3Ti4O12 ceramics by co-doping with Sr2+ and F- ions

Colossal dielectric permittivity, reduced loss tangent and the microstructure of Ca1−xCdxCu3Ti4O12−2yF2y ceramics

“…A great increase in grain size due to doping was also reported in earlier published papers. [6][7][8]27 This vastly increased grain size of the doped samples, compared to CCTO ceramic, might have been caused by liquid-phase sintering mechanisms. Generally, a liquidphase can form at junctions between particles or GBs, resulting in a much increased diffusion rate.…”

“…In advanced ceramics, essential raw materials for producing electronic components have been widely researched in this important eld. Focusing on capacitor applications, the colossal dielectric properties of polycrystalline ceramics, such as the codoped TiO 2 , 1,2,17,[20][21][22] codoped SnO 2 , 3 and ACu 3 Ti 4 O 12 (A ¼ Ca, [4][5][6][7][8][9]24 Cd, [10][11][12] Sm 2/3 , 13 Y 2/3 , 14 Na 1/2 Y 1/2 , 15 Na 1/2 Sm 1/2 , 25 Na 1/3 Cd 1/3 Y 1/3 16 ceramics have been developed and reported in the literature. Preserving high 3 0 values in these ceramics is the primary objective, followed by reducing loss tangents (tan d) and enhancing temperature/frequency stability.…”

“…Reports related to CaCu 3 Ti 4 O 12 (CCTO) based ceramics have been continuously published. [4][5][6][7][8][9][26][27][28][29] Due to its high 3 0 , numerous researchers have proposed an internal barrier layer capacitor (IBLC) structure, consisting of semiconducting grains and insulating grain boundaries (GBs). This was the rst model used to explain the colossal dielectric response in ACu 3 Ti 4 O 12 ceramics.…”

“…30 The most severe problem of CCTO for capacitor applications is its rather high tan d. Currently, modication of the preparation process and substitution of ions into the CCTO structure are frequently used to improve its dielectric and non-ohmic properties. [4][5][6][7][8][26][27][28][29] Additionally, modication of the A site of ACu 3 Ti 4 O 12 ceramics has also been a popular approach. [10][11][12][14][15][16]25 As previously reported by Yang et al, showed that doping Li + , Zn 2+ , Mg 2+ , and Zr 4+ into the CdCu 3 -Ti 4 O 12 structure can result in high 3 0 values of $1.0-5.0 Â 10 4 with low tan d values of $0.03-0.10.…”

Influences of Sr2+ Doping on Microstructure, Giant Dielectric Behavior, and Non-Ohmic Properties of CaCu3Ti4O12/CaTiO3 Ceramic Composites

“…For capacitor applications, tanδ of a dielectric material should be reduced as low as possible to prevent the dissipation of energy, while E b must be increased as high as possible for application in a high voltage level. Sr 2+ doping ions can improve the electrical properties of the internal interface (i.e., GBs) of CCTO ceramics, giving rise to the enhanced dielectric and nonlinear electrical properties [8,23,30,31]. Thus, using this concept, the objective of this work is to reduce tanδ of the CCTO/CTO composites with enhancing the nonlinear electrical properties by doping with Sr 2+ ions.…”