Depolarization field tuning of nanoscale ferroelectric domains in (001)PbZr0.4Ti0.6O3/SrTiO3/PbZr0.4Ti0.6O3 epitaxial heterostructures
Abstract
The effect of tuning the depolarization field in (001)-oriented ultrathin epitaxial PbZr0.4Ti0.6O3/SrTiO3/PbZr0.4Ti0.6O3 ferroelectric heterostructures is investigated. The thickness of the dielectric spacer (SrTiO3) is maintained constant at 2 unit cells. The ferroelectric layer thickness in the heterostructure (each PbZr0.4Ti0.6O3) layer varied from 8 to 15 nm is exploited as the parameter to tune the depolarization field. Piezoresponse force microscopy reveals a domain evolution from continuous labyrinthine domains to individual nanoscale bubble domains under the influence of an increasing depolarization field. A statistical analysis of the domain features (i.e., domain wall length and domain fraction) reveals that this change in domain morphology also affects the wall roughness and its associated disorder. The local coercive voltage obtained using switching spectroscopy piezoresponse force microscopy finds the 15 nm film to have the lowest coercive voltage. This is attributed to both a strain-induced increase in tetragonality and the depolarization field-induced changes in the domain morphology.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 13, 2021
- Source ID
- 10.1063/5.0035887
Entities
People
- Daniel Sando
- Nagarajan Valanoor
- Q Zhang
- Vivasha Govinden
Organizations
- Defense Advanced Research Projects Agency
- University of New South Wales