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Tip-enhanced Raman spectroscopy (TERS) and scattering-type scanning near-field optical microscopy (s-SNOM) enable optical imaging with a spatial resolution far below the diffraction limit of light. Although s-SNOM records the elastically scattered light (yielding information about the local refractive index and absorption), in TERS, the Raman scattered light is detected, which provides, for example, chemical information. Here, we introduce a combined TERS and s-SNOM setup for correlative studies of tip-enhanced elastically scattered and Raman scattered light. To that end, we equipped a conventional s-SNOM with a grating spectrometer. We validate our setup by characterizing a sample consisting of a self-assembled para-nitrothiophenol monolayer on an Au surface. Comparing s-SNOM and TERS signals, we demonstrate a qualitative correlation between the tip-enhanced elastic and tip-enhanced Raman scattered light. Thus, recording the tip-enhanced elastically scattered light enables a fast and reliable TERS alignm...

A controlled alignment of graphite nanoplatelets in a composite matrix will allow developing materials with tailored thermal properties. Achieving a high degree of alignment in a reproducible way, however, remains challenging. Here we demonstrate the alignment of graphite nanoplatelets in copper composites produced via high-energy ball milling and spark plasma sintering. The orientation of the nanoplatelets in the copper matrix is verified by polarized Raman scattering and electron microscopy showing an increasing order with increasing platelet size. The thermal conductivity k along the alignment direction is up to five times higher than perpendicular to it. The composite with the highest degree of alignment has a thermal diffusivity (100 mm(2) s(-1)) comparable to copper (105 mm(2) s(-1)) but is 20% lighter. By modeling the thermal properties of the composites within the effective medium approximation we show that (i) the Kapitza resistance is not a limiting factor for improving the thermal conductivity of a copper-graphite system and (ii) copper-graphite-nanoplatelet composites may be expected to achieve a higher thermal conductivity than copper upon further refinement.