Enhanced dielectric properties and grain boundary potentials in sulfur-doped CaCu3Ti4O12 thin films

Ye Seul Jung, Yong Soo Cho

Research output: Contribution to journalArticle

Abstract

CaCu3Ti4O12 (CCTO) has been reported to possess a colossal dielectric constant owing to the intrinsic interfacial polarization via charge accumulations across the grain boundary. Herein, we explore the effects of unusual anion-doping on the dielectric properties of sputter-deposited CCTO thin films using an example of sulfur-doping. A post-annealing process of the films was utilized in a flowing H2S atmosphere for the sulfur-doping. The incorporation of sulfur into the perovskite structure was evidenced with the changes in chemical states, such as the reduced cations of Cu+ and Ti3+, the increased concentration of oxygen vacancies, and the formation of S-O[sbnd] bonds. The sulfurized CCTO thin films demonstrated an enhanced relative permittivity of ∼620 at 100 Hz, which is substantially better than that of the unsulfurized film. Direct measurement of the grain-boundary potential using Kelvin probe force microscopy suggests that the enhanced relative permittivity is associated with an increased Schottky barrier height.

Original languageEnglish
Pages (from-to)2375-2381
Number of pages7
JournalJournal of the European Ceramic Society
Volume40
Issue number6
DOIs
Publication statusPublished - 2020 Jun

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Materials Chemistry

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