Direct imaging of LaAlO3/SrTiO3 nanostructures using piezoresponse force microscopy

The interface between LaAlO3 and TiO2-terminated SrTiO3 can be switched between metastable conductive and insulating states using a conductive atomic force microscope probe. Determination of the nanoscale dimensions has previously required a destructive readout (e.g., local restoration of an insulating state). Here it is shown that high-resolution non-destructive imaging of conductive nanostructures can be achieved using a specific piezoresponse force microscopy (PFM) technique. Images of conductive and insulating nanoscale features are achieved with feature sizes as small as 30 nm. The measured nanowire width from PFM is well correlated with those obtained from nanowire erasure.