Niobium targets are primarily employed in the reactive sputter deposition of niobium pentoxide (Nb₂O₅). Niobium oxide thin films are used as antireflective coatings for applications ranging from architectural glass to lenses, wave guides and filters. The optical coatings are comprised of alternating layers of niobium pentoxide (having a refractive index of about 2.17, similar to that of tantalum pentoxide) and a low refractive index material such as quartz (RI ~1.46).

Since impurities in the sputtering target can affect the optical properties of the Nb₂O₅ film, Cabot offers a special high purity, target grade niobium for this market.

Unique refining and melting capabilities, combined with precise thermomechanical processing, assures that Cabot's target grade niobium contains a fully re-crystallized microstructure having a nominal grain size less than 50mm (and a +3s range of 90mm). Like Cabot's tantalum sputtering products, our niobium target grade material provides superior performance reliability because the microstructure is free of severe textural and grain size banding.