Scanning Probe Studies of Structural and Functional Properties of Ferroelectric Domains and Domain Walls

This thesis explores the fascinating properties of domain walls in ferroelectric materials. Domain walls can be used as model systems to study fundamental aspects of interface physics, such as crackling noise, with implications extending to a broad variety of systems, from material fracture and earthquakes to solar flares and collective decision making. Ferroelectric domain walls also show functional properties absent from the domains themselves, such as enhanced conduction leading to the tantalizing possibility of reconfigurable nanoelectronic circuitry where domain walls are active components. This work discusses the crackling physics of domain walls in thin films of Pb(Zr0.2Ti0.8)O3, as well as links between the local conductivity of domain walls and nanoscale geometrical distortions due to defects, and discusses unusual polarization textures with rotational components at crossings of ferroelastic twin domains. The results presented in this thesishave important implications for the experimental study of crackling systems.

Auteur
Philippe Tückmantel obtained his Master in Physics in 2015 from the University of Geneva before continuing his graduate studies there. During his PhD, he worked mostly on nanoscale properties of domain walls in ferroelectric thin films using scanning probe microscopy techniques.

Contenu
Introduction and Motivation.- Ferroelectricity.- Crackling Noise and Avalanches.- Experimental Methods.- Crackling at the Nanoscale.