The MRSEC Facilities Network is a nationwide partnership of NSF supported MRSEC centers designed to provide support to researchers in the broad area of Materials Research in academic, government and industrial laboratories around the world.
Field Emission Gun Scanning Electron Microscope Hitachi S-900
Description
A Field Emission Gun Scanning Electron Microscope (FEGSEM) of "in-lens" design
capable of 0.8 nm resolution at 30 kV and 3-4 nm resolution at 1 kV.Â
Magnification ranges from 100 X to 800,000X. Electron source is a cold FE
gun producing high brightness (109 A / cm2/sr) with little energy spread
(<0.2 eV). Spherical and chromatic aberration coefficients of "objective"
lens (final condenser) are Cs = 1.9 mm and Cc = 2.5 mm, respectively.Â
The "in-lens" design imposes a sample size limit of ~ 5 mm W X 10 mm L X 2.5 mm
H. Oil-free vacuum systems pump column and sample exchange. Available
image modes include secondary and backscattered electron images. Two
specialized Gatan Model 626 cryostages are available for cryoSEM operation.Â
Digital images are acquired via an analog-to-digital converter / PCI system.
Equipment
Hitachi S-900 with a variety of non-cryo sample holders
CryoSEM observation using Gatan Model 626 cryostages
Backscatter imaging at TV rates and low voltage (threshold 1.8 kV on gold)
with Autrata modified YAG (yttrium aluminum garnet, cerium doped) crystal
Keithly Specimen Current Detector
Applications
High-resolution topographic contrast (Se) and atomic number contrast
(BSe) imaging of biological and non-biological samples in both room temperature
and cryo modes
Particularly applicable to imaging of immunogold labeled individual
cells and bacteria, analysis of semiconductor thin films, etc
