Characterization and Control of Domain Structure in SrBi2Ta2O9Thin Films by Scanning Force Microscopy

We used the piezoresponse mode of scanning force microscopy (SFM) to perform the first nanoscale observation of ferroelectric domain structure in as-grown SrBi2Ta2O9films. By lowering the loading force down to approximately 1 nN and by keeping the imaging voltage just below the coercive voltage, we managed to obtain a sufficiently high contrast between opposite 180° domains without affecting the original domain structure. Local and large-scale ferroelectric switching with subsequent readout in areas of about 0.01 µm2and 1.5 µm2, respectively, were carried out by applying pulsed- and dc-voltage bias through the conductive tip.