Size of ferroelectric field effects in oxide heterostructures
ORAL
Abstract
Ferroelectric field-effects allow the manipulation of the physical properties of strongly correlated oxides. This is achieved in heterostructures that combine these materials with ferroelectrics. Similarly, as in a transistor, a strong accumulation of charge is induced in the correlated oxide channel to screen the electric field from the ferroelectric gate, which results in a significant doping of the correlated material. Here we investigate the extrinsic factors that may limit the size of ferroelectric field-effects, which include among other the nanoscale structural and ferroelectric properties near the interface. The investigation is done via a combination of transport measurements (Hall effect and TC measurements), piezoresponse force microscopy (PFM), high-resolution scanning transmission electron microscopy (HR-STEM) and electron energy loss spectroscopy (EELS) in BiFeO3 (ferroelectric)/YBa2Cu3O7 (superconductor) heterostructures. We find that incomplete ferroelectric switching, probably associated to the interface atomic terminations, and changes in the carrier mobility that accompany the carrier concentration modulation, conspire to reduce the size of the field effects.
*Work supported by the ERC grant N. 64710 and French ANR grant ANR-15-CE24-0008-01
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Presenters
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Javier Villegas
- Unite Mixte de Physique CNRS/Thales
- Unité Mixte de Physique CNRS/Thales