Towards functional ferroelectrics for nanoelectronics
The PhD project focuses on the investigation of ferroelectric materials with respect to potential applications in resource efficient nanoelectronics, as sensors and circuitry. Ferroelectrics are ideal candidates, as they naturally contain polar regions and interfaces, namely domains and domain walls, which can be functionalised for nanoscale building blocks.
An important spatially resolved electrical characterisation technique that propelled the progress in this field is scanning probe microscopy (SPM). Different scanning probe techniques will be applied, such as piezoelectric response force
microscopy (PFM) and conductive atomic force microscopy (cAFM), to study three template systems for functional domain walls: lacunar spinels, hexagonal manganites and lithium niobate. By these measurements, domain and domain wall architectures with promising functionalities will be identified, such as highly non-ohmic electrical conductivity, an important prerequisite for sensors and circuitry.
Going beyond standard SPM techniques, more advanced approaches to generate multidimensional datasets will be applyed and developed. Local IV-spectroscopy, AC-cAFM and scanning dielectric spectroscopy, also in combination with external magnetic field sweeps, can be used to reveal and tune functional properties. The generated multidimensional datasets will be analysed with recently developed deep-learning (DL) architectures. This facilitates recognition of complex features across the datasets, e.g., deconvoluting the multitude of electronic contributions that coexist in ferroelectrics on the nanoscale.