Scanning electron microscopy uses a focused beam of
electrons to scan a sample under vacuum. This technique is designed primarily
for imaging samples over a range of magnification, typically from ~<100x to ≥30,000x.
The IUP microscopy lab contains a ThermoScientific Prisma E
SEM. Designed to be easy to use for a variety of user skill levels, the Prisma
E is a versatile research-grade SEM with a tungsten filament, state-of-the-art
imaging capabilities, and the ability to host a wide variety of specimens of interest
to researchers in myriad disciplines (e.g., anthropology, biology, geology).
The Prisma E includes a Back-Scattered
Electron (BSE) Detector, used in compositional imaging (e.g., to
distinguish between minerals and glass),
and a Secondary Electron (SE)
detector, used for topographic imaging, including 3D surfaces. The Prisma E can
also be operated under low vacuum or variable pressure conditions (e.g., ESEM
mode), which provides the capability to image non-conductive specimens that are
too fragile for high vacuum (such as biological specimens), too small to be
polished, or cannot be carbon coated (to reduce charging) before observation in
The Prisma E has a large sample chamber (340mm wide), which will
hold samples 85mm tall and can view a large area (up to122mm wide) of a sample,
due to XY movement with full rotation and up to 90° tilt. The largest field of view
is 18mm at the longest working distance. The Prisma E also has high-resolution
capabilities (3nm resolution at 30kV under high vacuum) and a magnification
range of 6x to 1,000,000x.