SPI Supplies Beryllium Planchet, 25.4 mm Diameter x 0.25 mm Thick, CAS #7440-41-7
Chemical Formula: Be
CAS #: 7440-41-7
Color: "Lead" grey
Melting point: 1287 °C (2349 °F)
Boiling point: 2469 °C (4476 °F)
Density of solid (/kg-3): 1848
All planchets (disks) are 0.25 mm thick
Individual, in its own plastic box for clean storage
Size: 9.5mm dia.
Beryllium has long been recognized as the ideal sample background for EDS analysis in the SEM. The low atomic number of beryllium assures the microscopist of spectra both free from unwanted and annoying characteristic x-ray peaks, and also low in Bremsstrahlung background radiation. SPI Supplies has switched to a new, higher purity beryllium metal than previously used for beryllium planchet (disk) production; characteristic x-ray peaks from impurities in the metal are virtually absent from beryllium disk only control spectra. These (disk) also feature a highly polished surface to minimize background affects. With proper cleaning, provided proper safety procedures are followed, they can be used over and over indefinitely. Planchets (disk) are available in three sizes, all 0.25 mm thick.
Surface finish: The surface roughness of the SPI beryllium planchets (disk) is equivalent to the finish obtained using a 1 µm polishing abrasive, although the surface is not produced using conventional polishing methods. The surface that does result has been found to be acceptable for a wide range of microscopy applications.
*The cleaning of beryllium planchets (disk) must be done according to recommended procedures in a way that does not generate particulates which could become very toxic if inhaled. Indeed anyone contemplating the use of beryllium should be familiar with some basic concepts about beryllium and the use of beryllium in the electron microscope laboratory.
Alternatives to the use of beryllium planchets (disks):
A growing number of institutions, because of the toxicity of beryllium oxide to cause great medical harm in a certain number of individuals, have putting tough restrictions on the use of even beryllium metal, or prohibiting its use altogether on their premises. A very excellent absolutely non-toxic alternative would be the use of the SPI Diamond Planchets (disks).