Scanning electron microscopy (SEM) is an electron microscopy technique in which a tiny beam of electrons is scanned across the surface of a sample. A high-resolution 3D image of the sample surface is generated when the electron beam strikes a metal-coated specimen and the electrons reflected (back-scattered) or given-off (secondary electrons) are detected.
Hitachi S4700 SEM (Ultrahigh resolution SEM with field-emission gun)
Hitachi S2600 SEM (Environmental/low vacuum variable pressure SEM)
Tousimis Critical Point Dryer and Cressington Sputter Coater to prepare samples for Hitachi S4700 SEM
Hitachi S2600 – samples are not required to be dehydrated and coated
Hitachi S4700 – samples are required to be dehydrated and coated
- Critical point dry (complete dehydration)
- Sputter coating (with Gold and/or Platinum)
Comparison of S4700 and S2600
|Hitachi S4700 Field emission (FE)-SEM||Hitachi S2600 Variable pressure (VP)-SEM|
|Resolution||Ultrahigh up to 2 nm||Relatively high up to 5 nm|
|Electron Gun||Field emission cold gun|
- very bright, tiny spot size, low voltage
|Tungsten thermionic gun
- less accurate beam spot
|Vacuum||Ultrahigh||Low, variable setting (1 – 270 Pa)|
|Sample Condition||Dry, coated with metal||Wet sample can be viewed
No sample preparation is needed
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