Issue 34, 2013

Non-stoichiometry in “CaCu3Ti4O12” (CCTO) ceramics


A combined powder X-ray lattice parameter and ceramic impedance spectroscopy study is presented on materials within the CaO–CuO–TiO2 ternary phase diagram. Several compositions containing CaCu3Ti4O12 (CCTO) and small amounts of secondary phases such as TiO2, CaTiO3 and CuO are analysed and two different defect mechanisms are identified as the cause of the non-stoichiometry in CCTO. The first mechanism involves a variation in the Cu content, which explains the large differences in the intrinsic bulk and extrinsic grain boundary (GB) resistance, and the formation of the ceramic internal barrier layer capacitor (IBLC) structure. The second mechanism is associated with Ca–Cu anti-site disorder causing an unusually high intrinsic bulk permittivity above that predicted from Clausius–Mossotti calculations.

Graphical abstract: Non-stoichiometry in “CaCu3Ti4O12” (CCTO) ceramics

Supplementary files

Article information

Article type
19 Mar 2013
24 May 2013
First published
24 May 2013
This article is Open Access
Creative Commons BY license

RSC Adv., 2013,3, 14580-14589

Non-stoichiometry in “CaCu3Ti4O12” (CCTO) ceramics

R. Schmidt, S. Pandey, P. Fiorenza and D. C. Sinclair, RSC Adv., 2013, 3, 14580 DOI: 10.1039/C3RA41319E

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