Domain wall dynamics in nanoscale ferroelectrics

Nanostructured ferroelectric oxides are now a part of high-density memory applications such as console video games, smart cards, probe based hard disk storage as well as materials for nano/micro-electro-mechanical systems (NEMS/MEMS). The motion of a ferroelectric domain wall is central to all these applications; it controls retention of data, speed of writing as well as scalability of a written bit. Here the paper presents a systematic investigation of the complex and diverse interplay between a domain wall and the microstructural features such as grain boundaries and defects. These experiments have been performed with a novel scanned probe based approach called piezoresponse force microscopy. With direct images we demonstrate the dominant role of local electrostatics in controlling the stability of a domain wall