The band excitation method in scanning probe microscopy for rapid mapping of energy dissipation on the nanoscale

TLDR

Mapping energy transformation pathways and dissipation on the nanoscale, and understanding how local structure influences dissipative behavior, is a key challenge for imaging across electronics, information technologies, and efficient energy production. The authors develop a family of novel scanning probe microscopy techniques that excite the cantilever over a band of frequencies simultaneously, rather than at a single frequency as in conventional SPMs. Band excitation SPM rapidly acquires the full frequency response at each point, enabling direct measurement of energy dissipation through the Q‑factor of the cantilever–sample system. The BE method is demonstrated for force–distance, voltage, and magnetic dissipation imaging with sensitivity near the thermomechanical limit, and the authors anticipate it will be universally applicable to ambient and liquid SPMs.

Abstract

Mapping energy transformation pathways and dissipation on the nanoscale and understanding the role of local structure in dissipative behavior is a key challenge for imaging in areas ranging from electronics and information technologies to efficient energy production. Here we develop a family of novel scanning probe microscopy (SPM) techniques in which the cantilever is excited and the response is recorded over a band of frequencies simultaneously, rather than at a single frequency as in conventional SPMs. This band excitation (BE) SPM allows very rapid acquisition of the full frequency response at each point (i.e. transfer function) in an image and in particular enables the direct measurement of energy dissipation through the determination of the Q-factor of the cantilever–sample system. The BE method is demonstrated for force–distance and voltage spectroscopies and for magnetic dissipation imaging with sensitivity close to the thermomechanical limit. The applicability of BE for various SPMs is analyzed, and the method is expected to be universally applicable to ambient and liquid SPMs.