Force Volume Atomic Force Microscopy-Infrared for Simultaneous Nanoscale Chemical and Mechanical Spectromicroscopy

The uploaded data is used in the following publication and its Supporting Information: Force Volume Atomic Force Microscopy-Infrared for Simultaneous Nanoscale Chemical and Mechanical Spectromicroscopy ACS Nano 2025, 19, 19, 18791–18803 https://doi.org/10.1021/acsnano.5c04015 ABSTRACT OF THE PUBLICATION: Photothermal atomic force microscopy-infrared (AFM-IR) combines the nanoscale spatial resolution of AFM with the chemical identification capability of infrared spectroscopy and has thrived in various applications. Currently executed in three major AFM modes (contact, tapping and peak force tapping) we introduce a fourth variant built upon force volume mode comprising a defined engage, hold and retract segment in each pixel. IR laser pulsing at a probe resonance frequency during the constant-force hold segment duplicates the resonance enhanced AFM-IR detection principle of contact mode. However, force volume AFM-IR removes the lateral forces that cause tip wear and sample damage while adding the spatial resolution of tapping AFM-IR. As demonstrated on different materials this imaging and spectroscopy technique integrates monolayer sensitivity, sub-10 nm spatial chemical resolution, simultaneous nanomechanical property sensing and precise force control. The ability to sweep the infrared laser repetition rate in each pixel provides additional, rich information in the form of contact resonance curves, while compensating for mechanically induced probe resonance shifts in an alternative to conventional phase-locked loop based frequency tracking. Such sweeps inherently consider the Q-factor (i.e. mechanical damping) in the AFM-IR response, a little investigated aspect. Furthermore, the probing depth can be varied by selecting different resonances recorded within a single broad frequency sweep. Switching to the surface sensitive AFM-IR detection scheme during the hold segment additionally limits the probing depth. These qualities should position force volume AFM-IR as a valuable addition to established AFM-IR modes. DESCRIPTION OF UPLOADED DATA: File names start with ‘Fig…’ followed by a short description and refer to the specific figure in the publication and its Supporting Information where the data is discussed. The following SI figures are based on the same data sets as other figures: Fig. S6: see spectra of Fig. 3 Fig. S7: same data as Fig. 4 Fig. S8: same data as Fig. 5 Fig. S10: same data as Fig. 5 Fig. S11: same data as Fig. 6. Data sets comprise atomic force microscopy (AFM) imaging files (*.spm, mostly containing force volume data), spectra (*.txt) or curves (*.txt) discussed in the publication. Txt-files contain ASCII data in tab delimited format. The atomic force microscopy (AFM) imaging files (*.spm) can be opened and processed in Bruker NanoScope Analysis V3.00R1sr7. Earlier Nanoscope Analysis versions as well as other AFM imaging software may be used as well but full compatibility is not guaranteed.