Ferroelectric domains and diffuse transitions in ultrathin films of PbTiO3: Effects of strain and electrodes

Summayya Kouser, Takeshi Nishimatsu, Umesh V. Waghmare

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We determine strain-temperature phase diagrams that map the stability of ferroelectric ordering and domains in nanothin (1.6-20 nm) films of PbTiO 3 using molecular dynamics based on a first-principles model Hamiltonian. The ferroelectric domain structure is shown to depend sensitively on the epitaxial strain and the nature of the electrodes that screen the surface charges of a ferroelectric. We show that a broad peak in the dielectric response as a function of temperature marks a diffuse transition to a flux closure stripe-domain structure in the ultrathin films with incomplete screening of charges at their interface with the electrode. We demonstrate that the strain-phonon coupling is fundamental to the stability and topology of such a domain structure, which can be engineered at the nanoscale with a suitable choice of electrodes and substrate, and used in ultrahigh-density memory chips.

Original languageEnglish
Article number064102
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume88
Issue number6
DOIs
Publication statusPublished - 2013 Aug 21

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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