On origin and intrinsic electrical properties of the colossal dielectric constant state in CaCu3Ti4O12

The CaCu3Ti4O12 (CCTO) thin films were deposited on Pt/TiO2/Ti/SiO2/Si (100) substrates by pulsed laser deposition. The temperature dependences of dielectric constant were measured in the as-produced thin film samples, showing the so-called colossal dielectric constant (CDC) phenomenon. I-V and C-V characterizations evidenced that the electrode interface formed a Schottky barrier, whose depletion capacitance resulted in the observed CDC in CCTO thin films, while the interior of the material was found to be a p-type doped semiconductor. The CDC state of CCTO can be switched off by annealing the samples in air at 600 to 700 degrees C. In the non-CDC state, the intrinsic dielectric constant of CCTO increases on cooling, showing an incipient ferroelectric feature. XPS depth profiles indicate that the p-type doped state in the bulk corresponds to partially reduced Cu++ ions combined with oxygen vacancies.

Published in:
Fundamentals And Technology Of Multifunctional Oxide Thin Films (Symposium G, Emrs 2009 Spring Meeting), 8, -
Presented at:
Conference on Fundamentals and Technology of Multifunctional Oxide Thin Films (Symposium G, EMRS 2009 Spring Meeting), Strasbourg, FRANCE, Jun 08-12, 2009
Iop Publishing Ltd, Dirac House, Temple Back, Bristol Bs1 6Be, England

 Record created 2011-12-16, last modified 2018-03-17

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