A continuum analysis of the driving force of ferroelectric/ferroelastic domain wall motions

First, Eshelby's driving force for the motion of a sharp interface is rederived from general thermodynamic principles. Ferroelectric and ferroelastic domain walls represent a special class of such interfaces in mechanically stressed crystals subject also to an electric field. The corresponding bulk contributions to the driving force are caused by variations of the ferroelectric/ferroelastic anisotropy energy, whereas the interface contributions arise from variations of the intrinsic surface energy of the domain wall and domain wall bending. The general expressions for the local driving force per unit area of such domain walls are specialized then to domain walls in piezoelectric crystals.