Significant stiffness reduction at ferroelectric domain boundary evaluated by ultrasonic atomic force microscopy

Two-dimensional resonance frequency mapping in the ultrasonic atomic force microscopy was applied to the investigation of the ferroelectric domain structure in lead zirconate titanate ceramics. This method can visualize the stiffness anisotropy due to the differently oriented domains. Moreover, the significant stiffness reduction at the ferroelectric domain boundary was discovered. The disorder of the lattice, the ability of the switching of the domain, and the reduction of the piezoelectric stiffening are possible explanations. The implication of this work is the characterization of novel functional materials on nanoscale and the nondestructive evaluation of the microelectromechanical systems and nanotechnology devices.