GEMS: Geoanalytical Electron Microscopy & Spectroscopy Centre

‌Samples are illuminated by laser light, and the reacted (Raman) light is collected and analysed with a spectrometer. Raman is a very weak effect, with only 1 in 10 million interactions. Characteristic spectra and peak properties (e.g. intensity, width) can be used to produce maps (Raman images) of the variation.

Raman light is collected and analysed with a spectrometer. Characteristics of Raman spectra are used to identify material present. Peak properties can be used to infer material properties such as crystallinity,stress and strain.

Chemical bonds absorb energy from the incident laser light causing them to vibrate. Energy absorbed from the laser causes the colour of the laser to change (Raman Shift). Lighter the end members of the bonds larger this Raman shift.