JEOL 8900 Electron Microprobe CapabilitiesThe electron microprobe at Binghamton University is fully computer automated and has the following major specifications:
- 4 wavelength-dispersive spectrometers (WDS): crystals = STE, LDE1, TAPJ, PET, LIF
- 1 energy-dispersive spectrometer (EDS): detector = Si(Li), Be window
- Electron beam imaging: Secondary-electron imaging
- Back-scattered imaging: Compositional (mean Z) and Topographic modes
- Light microscopy: reflected and transmitted (polarized) light
- Line analyses: (beam scan, X-Y stage scan):
- Multi-element area maps (beam scan, X-Y stage scan)
- Image analysis: Minimum pixel size for line and stage scans is 0.02 micron. Grey level or false-color digital enhancement
- Data manipulation:
- Analyses: Matrix corrections using ZAF, CITZAF, and Bence-Albee schemes.
- Data and Image output: Standard photographic media, magnetic media, color thermowax printer, or direct internet transfer to your e-mail address.
- Sample size: 100 x 100 x 50 (H) mm (max.), analyzable area of 90 x 90 mm (max.)
Best designed to handle conventional petrographic thin sections and 1-inch round disks.
Is the Electron Microprobe the right instrument for your project?
What the JEOL 8900 Electron Microprobe Can Do:
- Quantitative analysis of elements from Fluorine to Uranium
- Semi-quantitative analysis of elements from Boron to Oxygen
- Digital imaging using Back-scattered and Secondary Electrons – images generally good for particles down to 0.1 µm in width
- Digital X-ray mapping
- Four-spectrometer WDS system, Be-window EDS system
- Accept standard petrographic thin sections, 1-inch diameter, and 1.25-inch diameter metallurgical mounts
What the JEOL 8900 Electron Microprobe Cannot Do:
- Cannot routinely analyze particles < 5 µm in width or depth
- Cannot detect concentrations of elements below about 500 ppm (0.05 wt%)
- Cannot analyze H, He, Li, or Be because H and He produce no characteristic X-rays and because Li and Be have extremely low X-ray fluorescent yields
- Cannot do “thin film” analyses
- Cannot image features at the “nano” scale, i.e. 1-100 nm (10-1000 Å)
- Cannot analyze highly volatile or vacuum-sensitive samples
- Cannot analyze large samples (greater than 3/4-inch cube)
Optimal sample conditions (solids) for microprobe analyses:
- Hard (able to be polished)
- Flat (polish surface to ~0.5 µm grit diameter)
- Thick (>30 µm thick, thicker than a normal rock thin section)
- Conducting – but we routinely carbon-coat insulating materials
For instrument use and availability:
E-mail address: email@example.com
Telephone: (607) 777-7623
Typical Microprobe Mineral Analyses*
|Oxide (wt %)||Kakanui Hornblende Observed||(USNM 14365)||Durango Apatite Observed**||(USNM 104021)Reported**|
* nd = not determined
Standards used are: Si=SiO2, Al, K=orthoclase, Ti=TiO2, Mg=MgO, Fe=hematite, Mn=spessartine, Ca=diopside, Na=albite (Amelia), P=apatite (Wilberforce), F=fluorite, Cl=Kcl.
** Does not include 2.3 wt % total of REE, Na, S, etc.
Other standards available: (1) oxide/metal standards from C. M. Taylor Corp., (2) selected mineral standards from the Smithsonian Institution, and (3) selected glass standards from the Carnegie Institution of Washington, Geophysical Laboratory.