Centre for Geobiology

Confocal Laser Raman Microscope in place!

(from Geoviten-ekstern 18.12.2009) The department has recently installed a new Raman spectrometer at the Bergen Geoanalytical Facility on the second floor in Realfagbygget.

The Labram-HR of Horiba Jobin-Yvon consists of a high-resolution confocal Raman spectrometer with three laser wavelengths in the visual range, attached to a petrographic microscope with motorized mapping stage. This system measures the molecular vibrational energy of substances, and can thus be used for identification of various materials. Since vibrational energy is related to molecular bond strength, certain molecular characteristics can be studied, such as stress patterns in solids or isotopic variation in e.g. 13C-labelled biologic compounds.

Laser Raman spectroscopy will be used in the Centre for Geobiology as a rapid tool for mineral identification and characterization of microfossils in geological samples. In addition it is envisioned that this technique will be used for the characterization of fluid inclusions, biologic compounds, and products of biomineralization. For geologic samples we typically work with normal 30 Sm thinsections, although larger samples can be analyzed as well. For fluid inclusion studies 100 Sm thinsections are preferred. A typical analysis is entirely nondestructive, requires no further sample preparation, and takes place in a matter of seconds. Raman maps (2D- or 3D-maps) and depth profiles can be constructed in a matter of minutes to hours, depending on resolution (down to 0.3 Sm) and area (up to centimetres).

Although emphasis for us is on geological and biological samples, Raman spectroscopy can be applied to a wide variety of materials. Some interesting examples are: paintings and archaeological artefacts, stress patterns in silicon wafers, synthetic diamonds, real time reaction analysis in micro-reactors, cryogenic samples such as gas hydrates in ice.

Article taken from Geoviten-ekstern 18.12.2009