Differentiating 180° and 90° switching of ferroelectric domains with three-dimensional piezoresponse force microscopy

Three-dimensional (3D) piezoresponse force microscopy is applied in order to differentiate 90° and 180° domain switching in PbTiO3 (PTO) thin films. The 3D domain configuration is recorded both statically, revealing the surface crystallographic orientation of PTO films on the nanometer scale, and dynamically by simultaneously mapping the in-plane and out-of-plane hysteresis loops. We show that exclusively 180° switching occurs, also switching only half of the grain volume.