Contact potential measurement using a heated atomic force microscope tip

This letter reports contact potential measurement between the tip of a heated atomic force microscope cantilever and a biased gold film. Force-distance experiments were performed with tip temperature, tip potential, and substrate potential independently controlled. Experiments were conducted for probe temperatures of 23 to 200 degrees C and tip potentials of -1 V to 1 V. The measured contact potential was a function of temperature, due to the thermoelectric properties of the tip and substrate. The Seebeck coefficient for the combined system was close to -4.30 mV/K, consistent with the tip and substrate materials. The technique is scalable to arrays suitable for large area imaging. (c) 2007 American Institute of Physics.