Soft chemistry synthesis of the perovskite CaCu3Ti4O12

Abstract

OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. AbstractThe perovskite CaCu 3 Ti 4 O 12 (CCT) has been obtained after calcination of oxalate precursors at 900e 1000 C in air. Those precursors are prepared using a soft chemistry method, the coprecipitation. The oxalate powders consist of disk-like particles of 2e3 mm diameter and 300e400 nm thickness. By varying the ratio of the initial amounts of metal chlorides, additional phases (CaTiO 3 , TiO 2 and CuO) could be obtained besides CCT. The corresponding multiphased ceramics present improved dielectric properties.

Microstructure and Dielectric Properties of PTFE-Based Composites Filled by Micron/Submicron-Blended CCTO

“…The metal chlorides (CaCl 2 , TiCl 3 , and CuCl 2 -2H 2 O) were dissolved in water and added as precipitation agents to ethanol-containing oxalic acid. The precursors were calcined in air at 750 • C, 800 • C, and 850 • C for 10 h to obtain the oxide powders [28]. Micro-sized CCTO powder was synthesized by the solid-state reaction method [29].…”

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

“…These precursors were calcined in air at 950 • C for 10 h, in order to obtain the oxide powders. 8 The crystal structure of the oxide powders was confirmed by powder XRD recorded on a Seiffert XRD 3003TT (40 kV and 40 mA) using the Cu K␣ radiation over the 25-65 • 2θ range. XRD analyses were also performed on sintered pellets.…”

“…For these reasons, there has been a considerable interest in the study of the giant dielectric permittivity of the cubic ABO 3 perovskitetype CaCu 3 Ti 4 O 12 (CCTO) in the last decade. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] This material presents a so-called giant dielectric permittivity value that is mostly temperature-independent. 2,3 Many studies have been performed in order to understand the origin of this colossal dielectric permittivity, generally associated with an internal barrier layer capacitor (IBLC) effect.…”

“…The raw powders are prepared by the co-precipitation route followed by calcination, a single step process under air described elsewhere. 8 The colossal dielectric permittivity is obtained after optimizing the amount of the different phases in the material. The grain growth during sintering is controlled by the amount of excess CuO in the calcined powder, thanks to the formation of a CuO-TiO 2 eutectic.…”

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

“…Marchin et al [54] synthesized the CaCu 3 Ti 4 O 12 oxide by the oxalate precursors. Oxalate precursors are obtained by the coprecipitation of calcium, copper and titanium chlorides with oxalic acid.…”