Watching Domains Grow: In-situ studies of polarization switching by combined Scanning Probe and Scanning Transmission Electron Microscopy

摘要

Ferroelectric domain nucleation and growth in multiferroic BiFeO3 films isobserved directly by applying a local electric field with a conductive tipinside a scanning transmission electron microscope. The nucleation and growthof a ferroelastic domain and its interaction with pre-existing 71^{\circ}domain walls are observed and compared with the results of phase-fieldmodeling. In particular, a preferential nucleation site and direction-dependentpinning of domain walls is observed due to slow kinetics of metastableswitching in the sample without a bottom electrode. These in-situspatially-resolved observations of a first-order bias-induced phase transitionreveal the mesoscopic mechanisms underpinning functionality of a wide range ofmultiferroic materials.