ID13 Raman microProbe

The ID13 beamline now offers in-situ microfocus Raman Spectroscopy within the second Experimental Hutch (EH2) as a routine tool for user operation.

The microProbe, designed in collaboration with Renishaw PLC is coupled to the spectrometer using a 100 m single-mode fibre optic. The probe head coaxially delivers a focussed laser spot to the same position on the sample as the X-ray beam. The laser spot at the focal position is approximately 1 µm in diameter, comparable to the X-ray beam size from several different ID13 optics.

Top-down schematic showing simultaneous and on-axis laser and X-ray beam delivery.

The microProbe is coupled to the beamline control software for automatic triggering during X-ray data collection. This means that the two techniques can be used to simultaneously map an area of the sample, allowing the different information provided by each technique to be exploited during analysis.

Raman spectroscopy and X-ray scattering are complementary techniques on many different levels. They can provide structural information on a range of different length scales, from molecular bonds up to hundreds of nanometers (for SAXS). They complement each other in their phase- or volume-selectivity, whilst their non-destructive nature (for many materials) makes them ideal for coupling with other methods. They therefore have a diverse range of potential applications, from studying deformation micromechanics and monitoring chemical reactions to characterising materials over both macro- and micro-scopic length scales.

The simultaneous spatial-resolution of Si and Ta structures using combined microRaman and micro-focused XRD. The 1.5 µm wide Si channels can been resolved from the integrated intensity of the 520 wavenumber Si Raman band at each scan position. Meanwhile, the 1.5 µm wide Ta blocks can be resolved using WAXS from the integrated intensity of the 002 Ta ß-phase reflection.