1 research outputs found
Atomic and Electronic Structure of the BaTiO<sub>3</sub>/Fe Interface in Multiferroic Tunnel Junctions
Artificial multiferroic tunnel junctions combining a
ferroelectric
tunnel barrier of BaTiO<sub>3</sub> with magnetic electrodes display
a tunnel magnetoresistance whose intensity can be controlled by the
ferroelectric polarization of the barrier. This effect, called tunnel
electromagnetoresistance (TEMR), and the corollary magnetoelectric
coupling mechanisms at the BaTiO<sub>3</sub>/Fe interface were recently
reported through macroscopic techniques. Here, we use advanced spectromicroscopy
techniques by means of aberration-corrected scanning transmission
electron microscopy (STEM) and electron energy-loss spectroscopy (EELS)
to probe locally the nanoscale structural and electronic modifications
at the ferroelectric/ferromagnetic interface. Atomically resolved
real-space spectroscopic techniques reveal the presence of a single
FeO layer between BaTiO<sub>3</sub> and Fe. Based on this accurate
description of the studied interface, we propose an atomistic model
of the ferroelectric/ferromagnetic interface further validated by
comparing experimental and simulated STEM images with atomic resolution.
Density functional theory calculations allow us to interpret the electronic
and magnetic properties of these interfaces and to understand better
their key role in the physics of multiferroics nanostructures