The Making of LaB₆ Crystals

Extract

The following image is of a LaB₆ crystal formation created at the FEI Company, Hillsboro, Oregon. The photograph was taken through a Bausch & Lomb Stereo Zoom 4 at 30X with a Polaroid MicraCam.

The single crystal LaB₆ and CeB₆ is grown and fabricated at FEI using a well-defined process known as "Inert Gas Arc Float Zone Refining." This process takes place in an inert gas atmosphere and utilizes an electrical arc to melt the hot, pressed powder sample of LaB₆ or CeB₆. This not only allows the growth of the crystal, but also hefps to purify the material. Through research and 20 years of experience in the growth of rare-earth boride single crystals, FEI can carefully control the material composition (e.g. stoichiometry of B/La) tor the highest possible ratio of electron emission to evaporation rate.