Department purchases new SEM

Posted on 02.23.2016
A new scanning electron microscope (SEM) was purchased for the Department in December, with funds from the Ralph E. Grim endowment, combined with funds from a grant from the NSF Instrumentation program to Prof. Craig Lundstrom.

The electron microscope, with X-ray analysis system, allows researchers to image and generate elemental concentration maps on geological samples. An electron beam is focused onto the sample, causing electrons and X-rays from the individual atoms to emanate and be detected.  

“Its great for seeing the elemental distribution among different minerals as well as the compositional zoning within an individual crystal,” said Lundstrom, “We can then use the map to determine a quantitative mineral composition, rivaling the much more complicated and expensive electron microprobes often used in geology.”

The new instrument replaces the previous SEM, which was nearly thirty years old and required special high voltage power and chilled water to operate. The new SEM, which only needs a standard electrical outlet for power, makes for simple use and has become a part of regular undergraduate lab classes. The SEM was used in Lundstrom’s Intro to Petrology class in the Spring semester by students for their lab project (see picture). 

“It’s a very easy instrument to use because the students can do an X-ray map showing the chemical compositions of all the phases in a rock thin section,” said Lundstrom.