Conductivity of twin-domain-wall/surface junctions in ferroelastics: Interplay of deformation potential, octahedral rotations, improper ferroelectricity, and flexoelectric coupling

Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Y. Borisevich, Long Qing Chen, Venkatraman Gopalan, Sergei V. Kalinin

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

Electronic and structural phenomena at the twin-domain-wall/surface junctions in the ferroelastic materials are analyzed. Carriers accumulation caused by the strain-induced band structure changes originated via the deformation potential mechanism, structural order parameter gradient, rotostriction, and flexoelectric coupling is explored. Approximate analytical results show that inhomogeneous elastic strains, which exist in the vicinity of the twin-domain-wall/surface junctions due to the rotostriction coupling, decrease the local band gap via the deformation potential and flexoelectric coupling mechanisms. This is the direct mechanism of the twin-wall static conductivity in ferroelastics and, by extension, in multiferroics and ferroelectrics. On the other hand, flexoelectric and rotostriction coupling leads to the appearance of the improper polarization and electric fields proportional to the structural order parameter gradient in the vicinity of the twin-domain-wall/surface junctions. The "flexoroto" fields leading to the carrier accumulation are considered as an indirect mechanism of the twin-wall conductivity. Comparison of the direct and indirect mechanisms illustrates a complex range of phenomena directly responsible for domain-wall static conductivity in materials with multiple order parameters.

Original languageEnglish (US)
Article number085416
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume86
Issue number8
DOIs
StatePublished - Aug 8 2012

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Conductivity of twin-domain-wall/surface junctions in ferroelastics: Interplay of deformation potential, octahedral rotations, improper ferroelectricity, and flexoelectric coupling'. Together they form a unique fingerprint.

  • Cite this