Charged domain walls in ferroelectric materials are accompanied by a high density of charges screening the jump in the polarization. This causes fundamental changes in the electronic structure close to the domain wall; it was even anticipated that magnetic moments can be induced in otherwise non-magnetic materials. This effect was indeed observed in ferroelectrics containing charges e.g. due oxygen vacancies. We propose to search for magnetic properties induced by various charge carriers also in charged domain walls in ferroelectrics: this would enable us to achieve magneto-electric coupling and controlled operations thanks to the domain walls motion. To this aim, we will combine electron and scanning probe microscopies for microscale characterization, magnetization measurements, thermal noise and conventional impedance spectroscopy for sensing macro-scale properties, with calculations using the phenomenological Landau-Ginzburg-Devonshire theory. This will allow us to obtain a detailed picture of the electronic and magnetic structure of charged domain walls in ferroelectrics.
Local magneto-electric properties of ferroelectric charged domain walls
Abstract