Nanoscale domain switching and 3-dimensional mapping of ferroelectric domains by scanning force microscopy

Nanoscale switching of ferroelectric domains in Barium-titanate and Tri-Glycine Sulphate bulk single crystals is demonstrated at room temperature by scanning force microscopy. Oppositely polarised domains are created by choosing an adequate polarity for the de voltage applied to the conductive tip : a positive bias at the tip results in the polarisation pointing into the crystal, and vice versa. Direct writing of lines measuring as small as 500 nm is demonstrated. Any structure written by this method is imaged with voltage modulated scanning force microscopy. Applying an ac voltage to the conductive tip reveals the electric field at the sample surface originating from both in-plane and out-of-plane polarised domains in ferroic samples. With this method domain walls are resolved down to 80 nm.