Raman Microscopy

The Mineral Sciences Department is outfitted with a Horiba ExploRa+ dispersive Raman microscope.  Two lasers can be selected, a 532 nm and a 785 nm, with automated calibration for each laser.  Typical Raman spectra for the 532 nm laser can be collected from 70 cm-1 to 4200 cm-1, while the 785 nm laser spectral range is nominally from 40 cm-1 through 2500 cm-1.  Slits can be used to obtain better spectral resolution from a selection of 50, 100, 200um, and the microscopic can be used in confocal mode by selecting a pinhole, 100, 200, and 500 um.  Laser power at the sample is adjustable, with a maximum of 15.2 mW at the sample.  Diffraction grating options are 600 gr/mm, 1200 gr/mm, 1800 gr/mm, and 2400 gr/mm, where the 1800 gr/mm is most commonly used.  A 10x (0.1 N.A.) and 100x (0.9 N.A.) objectives are available.  An automated XYZ stage controls sample positioning and mapping procedures.  Calibrations are performed daily and ambient room temperature is recorded every 5 minutes.  Temperature changes can affect the measured positions of the Raman bands.  Both transmitted and reflected light illumination is possible.

X-ray Fluorescence Microscope