Scanning Electron Microscopy: The Philips XL30 Environmental Scanning Electron Microscope (SEM) is one of a generation of SEMs that is completely controlled from a computer workstation. The XL series instruments are controlled by a personal computer running Microsoft Windows NT. This EMAL instrument employs a tungsten filament and is capable of functioning in both high vacuum mode and ESEM mode . This makes the instrument ideal for both imaging and microanalysis of a wide range of both electrically conducting and insulating materials.
- SEM, BSE imaging, Cryo-stage, XEDS, remote control
- 0.5 to 3.0 kV (100 V steps)
- 3.0 to 30 kV (1 kV st
- ~10^-6 torr in sample chamber
- Imaging: Everhart-Thornley & Solid State Backscatter Detector
- Gaseous Secondary Electron Detector
- XEDS: UTW Si-Li Solid State X-ray Detector (with integrated EDAX Phoenix XEDS system)
- Cryo-stage by Oxford Instruments
- 20 - 600,000x
- 2.5nm at 30kV - high vacuum
- 4.0nm at 30kV - 5 Torr of water vapor
- 6.0nm at 1k
- Samples must be compatible with high vacuum, i.e. clean and dry.
- Samples should be handled with tweezers or gloves.
- A large range of sample sizes will fit into the chamber up to a limit of about 6 inches in diameter and/or ~ 2 inches tall.
- You may not be able to access the entire area of a very wide sample. Ask for assistance if you are approaching the limits.
- High Vacuum Mode
Samples need to be conductive in high vacuum mode. Semi-conductors are OK. Non-conductive samples should be coated with a conductive layer. Conductive samples surrounded by a non-conducting medium should be provided with a conductive path to the SEM stub.
- ESEM Mode
Samples may be insulating or conducting, a rounding path as close to the sample area of interest is still an excellent idea.
SEM Class Lecture Notes
- Zoom in and out on an SEM sample
- Contrast mechanisms arising from sample topography in the SEM
- Energy Dispersive X-ray Spectroscopy - how the x-rays are generated
Application Notes for ESEM
- A Dandelion Seed Head - An example of some of the unusual samples that may be examined in the Environmental Scanning Electron Microscope.