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Tip Enhanced Raman Scattering (TERS, nanoRaman) is the technique for enhancement of weak Raman signals and for superresolution Raman imaging with spatial resolution less than 10 nm. As a result of comprehensive research performed together with NTMDT SI customers and partners, we are now able to offer to AFMRaman customers mass produced reproducible TERS probes. TERS imaging requires prolonged tipsample contact at each scanning point but Contact AFM is destructive for both the tip and the sample. Thereby, HD mode is a superior technique for cantilevertype TERS since it noticably increases the tip lifetime and makes possible TERS imaging of soft, loose and fragile samples. Vacuum measurements in amplitude modulation (AM) mode requires unacceptably low scanning speeds because of extremely high Qfactor of AFM probes. Being a nonresonant mode, HD mode allows at least 10 times faster imaging speed.

HD Scanning Thermal Microscopy (HD SThM) allows studying local thermal properties simultaneously with QNM measurements. From the hardware point of view it was implemented using AppNano VertiSense™ thermocouple probes. The thermal conductivity and temperature mapping modes (CMM, TMM) can be realized by positioning the AFM laser at the end or the central part of the probe, respectively. HD mode working principle allows exceptional spatial resolution of SThM measurements in comparison to conventional Amplitude Modulation (AM) mode. That was demonstrated in TMM of a microheater sample. SThM and HybriD mode is the winning combination for distinguishing between the constituents of polymer blends as demonstrated in the example of a blend of polystyrene (PS) with low density polyethylene (LDPE) (see below). The difference in thermal conductivity of the polymers (PS – 0.12 W/mK; LDPE – 0.33 W/mK) allows the assignment of the colder matrix to LDPE and the hotter islands to PS.

Stateoftheart HybriD 2.0 Control Electronics incorporates highspeed digital lockin amplifiers (LIA) and phase locked loop detector (PLL) for advanced oscillatory resonance modes Amplitude Modulation with Frequency Imaging (AMFI) and Frequency Modulation (FM) modes. They provide exceptional level of spatial resolution of challenging flat and soft samples (selfassembled molecular structures etc.) thanks to ultraprecise control of the tipsample interaction force. Additionally they allow mapping of its mechanical properties. The two images below show topography and probe resonant frequency distribution over lamellar arrangement of short alkane C36H74 on graphite with a spacing of 4.5 nm. One can also see a couple of adsorbates formed on the lamellar surface by disordered alkane chains which are rarely observed by the traditional AM mode.