Instrumentation Details

The Cameca SXFive is a fully automated electron microprobe with a LaB6 electron gun and five wavelength dispersive spectrometers that contain large area diffraction crystals and complementary counters.  The instrument was specifically designed with a LaB6 electron gun and large area diffraction crystals facilitate chemical analysis down to trace element concentrations.

The LaB6 electron gun can produce high beam currents (up to microampere levels) required to produce X-ray count rates from trace element concentrations of elements in materials.  Additionally, the LaB6 source can deliver a smaller beam diameter than a tungsten source, which improves spatial resolution for all types of analyses.  Scanning electron imaging is performed using backscattered and secondary electron detectors.  A cathodoluminescence detector can be used to observe compositional zoning that cannot be observed with backscattered electron imaging in some materials, and is especially useful for studying light emitting diodes (LED).  The integrated energy dispersive spectrometer is be used to quantify many major elements that can be spectrally resolved. The has five WDS spectrometers with a selection of diffracting crystals and detectors capable of measuring all elements with Z>4.  One spectrometer will contain four standard-sized diffracting crystals (TAP, PET, pseudocrystal for carbon to fluorine, and a pseudocrystal for boron to oxygen).  The remaining four spectrometers are outfitted with large-sized diffracting crystals to facilitate trace element measurements.  Because of their size, only two crystals can fit in each spectrometer.  The spectrometers have four large-sized PETs, a large-sized TAP, two large-sized LIFs and a large-sized pseudocrystal for (5B to 8O).  To perform accurate measurements of carbon and nitrogen, a decontamination system uses an oxygen beam to clean sample surfaces prior to and during analyses.  The lab is equipped with a system to coat electrically insulating materials with carbon and metals.