Peakforce photothermal-based detection of IR nanoabsorption

摘要

An apparatus and method of performing photothermal chemical nanoidentification of a sample includes positioning a tip of a probe at a region of interest of the sample, with the tip-sample separation being less than about 10 nm. Then, IR electromagnetic energy having a selected frequency, ω, is directed towards the tip. Using PFT mode AFM operation, absorption of the energy at the region of interest is identified. Calorimetry may also be performed with the photothermal PFT system.

主权项

1. A method of locally measuring IR absorption of a sample, the method comprising:
causing a probe to interact with a sample in an oscillating mode of AFM operation; directing a locally amplified IR signal toward a sample; and identifying a change in modulus based on the directing step; and wherein the oscillating mode uses feedback to control the interaction between the probe and the sample, and wherein the feedback is based on a localized detected force between the probe and the sample in each oscillation cycle.