CaCu3Ti4O12 ceramics from co-precipitation method: Dielectric properties of pellets and thick films

Abstract

International audienceDielectric properties of CaCu3Ti4O12 (CCTO)-based ceramics and thick films (e ∼50m) prepared from powders synthesized by a soft chemistry method (co-precipitation) are presented and discussed. The characteristics of pellets and thick films are compared. The pellets exhibit high values of the dielectric permittivity (εr ∼1.4×105) and relatively small dielectric losses (tan δ ∼0.16) at 1 kHz and room temperature. These properties are independent of the nature of the metallization of the electrodes. In addition, the dielectric permittivity decreases when the diameter of the electrodes of the pellets increases, while the losses remain constant. This result, which is strongly related to the nature of the dielectric material in between the electrodes, constitutes a strong indication that the high dielectric permittivity values observed in this material are not related to an interfacial (electrode material) related mechanism but is an internal barrier layer capacitor (IBLC) type. Very high values of the dielectric permittivity of CCTO thick films are measured (εr ∼5×104). The differences in dielectric permittivity between thick films and dense pellets may be attributed to the difference in grain size due to different CuO contents, and to the different reactivity of the materials

Structural, Dielectric and Electrical Properties of (1-x)CaCu3Ti4O12−xBaTiO3 Ceramics

“…A high dielectric loss appeared in the CCTO ceramic process as compared with BaTiO 3 [1,6]. There are several researches on the CCTO and BaTiO 3 ceramics which tried to improve the dielectric properties of these materials by controlling the manufacturing operations such as method, substitution, sintering time or temperature and calcinations time or temperature [11][12][13][14] and others tried to identify the nature of continued high dielectric constant of these ceramics [15,16]. Through our knowledge there is no any work to manufacturing ceramic which follow Structural, Dielectric and Electrical Properties of (1-x)CaCu 3 a mixture CCTO and BaTiO3 characteristics.…”

Application of High Permittivity Bismuth Copper Titanate in Multilayer Capacitors

“…Lead-free nonferroelectric high dielectric constant materials with perovskite structure and ACu 3 Ti 4 O 12 composition (A = Ca, Bi 2/3 , Y 2/3 , La 2/3 , Nd 2/3 , Sm 2/3 , Gd 2/3 , Dy 2/3 ) [6][7][8][9][10][11][12] could be promising candidates to replace relaxors as dielectrics in MLCCs. These compounds exhibit relatively low sintering temperature enabling co-firing with Ag electrodes.…”

“…Most of the publications concerning these materials have focused on ceramics and thin films. So far, the application * corresponding author; e-mail: dszwagi@ite.waw.pl of ACu 3 Ti 4 O 12 compounds in thick films and low temperature co-fired ceramics (LTCC) technology has been rarely investigated [7,9]. The present paper reports on preparation of green tapes based on Bi 2/3 Cu 3 Ti 4 O 12 , as well as on fabrication and characterization of multilayer capacitors with dielectric layers based on this ceramic.…”

An Overview on Recent Developments in the Synthesis, Characterization and Properties of High Dielectric Constant Calcium Copper Titanate Nano-Particles

“…Barbier et al [52] studied the electrical properties of CaCu 3 Ti 4 O 12 -based pellets and thick films obtained from the similar raw precursor prepared by the co-precipitation method.The metal chlorides (CaCl 2 , TiCl 3 and CuCl 2 ·2H 2 O) were dissolved in water and then poured in ethanol-containing oxalic acid used as the precipitating agent. In order to obtain oxide powders, these precursors were calcined in air at 950 o C for 10 h and the dielectric characteristics of pellets and thick films were compared.The pellets exhibit high values of the dielectric permittivity (ε r ∼1.4×10 The micro-structural features as revealed by the HRTEM in nano-scale indicate that CuO 4 groups with the squashed tetrahedral geometry are more prevalent in the exterior regions of the powder particles as compared to the predominance of square-planar CuO 4 in the interior.…”