Ionically-Mediated Electromechanical Hysteresis in Transition Metal Oxides

Yunseok Kim, Anna N. Morozovska, Amit Kumar, Stephen Jesse, Eugene A. Eliseev, Fabien Alibart, Dmitri Strukov, Sergei V. Kalinin

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66 Citations (Scopus)


Nanoscale electromechanical activity, remanent polarization states, and hysteresis loops in paraelectric TiO2 and SrTiO3 thin films are observed using scanning probe microscopy. The coupling between the ionic dynamics and incipient ferroelectricity in these materials is analyzed using extended Landau-Ginzburg-Devonshire (LGD) theory. The possible origins of electromechanical coupling including ionic dynamics, surface-charge induced electrostriction, and ionically induced ferroelectricity are identified. For the latter, the ionic contribution can change the sign of first order LGD expansion coefficient, rendering material effectively ferroelectric. The lifetime of these ionically induced ferroelectric states is then controlled by the transport time of the mobile ionic species and well above that of polarization switching. These studies provide possible explanation for ferroelectric-like behavior in centrosymmetric transition metal oxides.

Original languageEnglish
Pages (from-to)7026-7033
Number of pages8
JournalACS Nano
Issue number8
Publication statusPublished - 28 Aug 2012

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

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