Electron Microprobe

Electron Microprobe

The Jeol JXA-8530F Field emission microprobe (installed in 2010) provides an analytical resolution of a micron down to a few hundred nanometers, depending upon the material. It belongs to the Facility For Analysis Characterisation Testing Simulation (FACTS) at NTU.

The Jeol JXA-8530F is equipped with 5 wavelength dispersive spectrometers (WDS) and an energy dispersive (ED) silicon drift detector (SDD), which are fully integrated allowing combined analysis. It is also equipped with a cathodoluminescence detector and to reduce contamination for low voltage analysis a nitrogen cold trap. Imaging and locating positions for analysis are done using secondary electron (SE) and backscattered electron (BSE) images. The probe has an optical microscope but its high magnification means it is generally only useful for ensuring the sample is in optical focus.

This electron microprobe is used to study the composition of crystals in volcanic rocks, and thus determine accurately the conditions (pressure and temperature) of their formation. Such details make possible a reconstruction of eruptive history (magma mixing episodes) and a study of volcanic mechanisms at depth.