Thermal Measurements Using Multiple Frequency Atomic Force Microscopy

摘要

Apparatus and techniques for extracting information carried in higher eigenmodes or harmonics of an oscillating cantilever or other oscillating sensors in atomic force microscopy and related MEMs work are described. Similar apparatus and techniques for extracting information from piezoelectric, polymer and other materials using contact resonance with multiple excitation signals are also described.

主权项

1. A method of operating an atomic force microscope which includes a cantilever probe, comprising:
exciting a chip of the cantilever probe at two or more different synthesized frequencies that have been summed together by a circuit element, where the two synthesized frequencies each comprise resonance frequencies of the cantilever probe; providing each synthesized frequency as a reference signal to a lock-in amplifier; heating a tip of the cantilever probe; and measuring deflections of the cantilever probe caused by expansion and/or melting of the tip of the cantilever probe based on said heating, using a feedback loop to maintain the tip at a desired location relative to a surface of a sample, to characterize the surface.