Surface deformation and ferroelectric domain switching induced by a force microscope tip on a La-modified PbTiO3 thin film

Surface deformation of a ferroelectric (111)-oriented thin film of La-modified PbTiO3 is induced by contact with the tip of a scanning force microscope (SFM). The deformation is accompanied by switching of the out-of-plane polarization of ferroelectric domains revealed by simultaneous piezoresponse force microscopy. The effect shows up in topographic SFM images as strokes in the fast scan direction due to surface deformation occurring below the scanning tip, and is critically dependent on the contact force for which a threshold value is deduced that allows proper SFM characterization of such thin films. At higher force, SFM might be used as a nanoscale tool for investigating fundamental properties like phase transitions under applied stress in such systems.