Improved dielectric properties of the CaCu3Ti4O12 composites using BaTiO3-coated powder as precursor

Strongly Enhanced Dielectric Response and Structural Investigation of (Sr2+, Ge4+) Co-Doped CCTO Ceramics

“…However, it is difficult to estimate the R gb value from the Z * plot because of the sample-electrode effect observed in the CCTO and Sr05 ceramics, as shown in Figure . Estimating the R gb value can be made using the electric modulus ( M *) technique . The relationship to calculate the C gb and R gb values using the M * technique is as follows where M max ″ is the maximum value of the peak of the imaginary part ( M ″-peak) of M *, τ gb = 1/2π f max is the variation relaxation time, and f max is the relaxation frequency.…”

“…Estimating the R gb value can be made using the electric modulus (M*) technique. 41 The relationship to calculate the C gb and R gb values using the M* technique is as follows where M max ″ is the maximum value of the peak of the imaginary part (M″-peak) of M*, τ gb = 1/2πf max is the variation relaxation time, and f max is the relaxation frequency. The frequency dependence of M′ and M″ for the CCTO, Sr05, and Sr05Ge05 ceramics is given in Figure 8a−c.…”

Investigation of microstructure, ferroelectric and dielectric behavior of CaCu3Ti(4−x)MnxO12 perovskites synthesized through semi-wet route

“…The atomic Table 1 with different compositions confirming the stoichiometry and purity of CCTMO ceramic materials. Figure 4a depicts 2D atomic force micrograph (AFM) of CaCu 3 Ti 4−x Mn x O 12 (x = 1.00) ceramic sintered at 1223 K for 8 h. The 2D micrograph illustrates the bimodal structures of grains separated from the grain boundary [26]. The average roughness (R a ) and root mean square roughness (R q ) were found to be 72 nm and 90 nm, respectively, on a scanned area 20 µm × 20 µm.…”

Dielectric response of TiO2 ceramics: The crucial role of Ta2O5

“…[1][2] High-dielectric-constant oxides have become essential for modern microelectronic devices, such as dynamic random access memory (DRAM) devices and on-chip capacitors. [3] During the past several decades, several types of Colossal permittivity (CP) material have been available, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] such as BaTiO 3 , [4][5][6][7] ACu 3 Ti 4 O 12 (ACTO), [8][9][10][11][12][13][14][15] NiO, [16.17] SrTiO 3 , [18] and (Pb, La)TiO 3 , [19] as well as their substitutions by acceptor and donor dopants. For these CP materials, a higher ε r is always accompanied by a higher tanδ, while there is a poor dependence of dielectric properties on temperature and frequency, [4][5][6][7][8][9][10][11][12][13][14][15]…”

“…Furthermore, although a higher ε r were obtained in ACu 3 Ti 4 O 12 and La 1.7 Sr 0.3 NiO 4 , their tanδ were always greater than 20%. [8][9][10][11][12][13][14][15]19] As a result, it is very necessary to reduce tanδ under a large ε r in the CP materials for application. TiO 2 materials have been extensively investigated because of their good electrical properties.…”