Binghamton University
Electron Microprobe Regional Facility

JEOL 8900 Electron Microprobe Capabilities

• 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 Can NOT Do:

• Can not routinely analyze particles < 5 µm in width or depth
• Can not detect concentrations of elements below about 500 ppm (0.05 wt%)
• Can not 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
• Can not do “thin film” analyses
• Can not image features at the “nano” scale, i.e. 1-100 nm (10-1000 Å)
• Can not analyze highly volatile or vacuum-sensitive samples
• Can not 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, contact Mr. William H. Blackburn, Microprobe Supervisor
  Telephone: (607) 777-7623
  e-mail: probe@binghamton.edu

Typical Microprobe Mineral Analyses*

* 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.

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Last modified: October 5, 2007 (adh)