Polarization of domain boundaries in SrTiO3 studied by layer group and order-parameter symmetry

Author(s)
W. Schranz, C. Schuster, A. Tröster, I. Rychetsky
Abstract

Based on a recently developed combination of layer group analysis with order-parameter symmetry, we study the polarity of antiphase domain boundaries (APBs) and ferroelastic twin boundaries (TBs) in SrTiO3. In addition to the celebrated layer group analysis of domain twins, the present method allows us to investigate tensor properties of domain walls also for the case where order-parameter variables other than the spontaneous ones are active. We find that antiphase boundaries in SrTiO3 can carry a polarization if in addition to the spontaneous order parameter (0, 0, phi(s)) a second component, i.e., (phi(1), 0, phi(s)), develops within the domain wall. This result, which is solely based on symmetry arguments, strongly suggests that polarization in APBs is possible if a phase transition from an Ising-type wall to a Neel- or Bloch-like wall occurs. This is in very good agreement with previous calculations based on Landau-Ginzburg free energy expansions including biquadratic (proportional to PiPj phi(k)phi(l)) [A. K. Tagantsev et al. Phys. Rev. B 64, 224107 (2001)] and flexoelectric (proportional to P-k partial derivative u(ij)/partial derivative xi) coupling terms [A. N. Morozovska et al. Phys. Rev. B. 85, 094107 (2012)]. The present results also unveil a close connection between the recently discovered macroscopic polarization in antiferrodistortive cycloids of ferroelastic domain walls of SrTiO3 and a mechanism for explaining polarization of APBs.

Organisation(s)
Physics of Functional Materials, Computational and Soft Matter Physics
External organisation(s)
Czech Academy of Sciences, Universität Wien
Journal
Physical Review B
Volume
102
No. of pages
12
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.102.184101
Publication date
11-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter, 103018 Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/polarization-of-domain-boundaries-in-srtio3-studied-by-layer-group-and-orderparameter-symmetry(573a996e-b4cb-4944-9ed3-283a24997fb9).html