Mechanical crosstalk between vertical and lateral piezoresponse force microscopy

Piezoresponse force microscopy (PFM) provides valuable insight into the inverse lateral and vertical piezoelectric effects on the nanoscale. Ideally, these contributions are separated into vertical and lateral detections of a deflected laser beam on a quadrupole diode. In contrast to the known crosstalk by a rotated diode that causes identical signals in both channels, we report on the crosstalk due to the geometrical constraints of the cantilever that is inherent to the lateral PFM. For a BaTiO3 (001) nanograin we show that the vertical response attributable to the crosstalk is 1/8th of the lateral response. From this value we deduce the actual mechanism responsible for the crosstalk. (c) 2006 American Institute of Physics.