Niobium Pentoxide Sputtering Targets - Nb2O5

Niobium pentoxide is the inorganic compound with the formula Nb2O5. It is a colourless insoluble solid that is fairly unreactive. It is the main precursor to all materials made of niobium, the dominant application being alloys, but other specialized applications include capacitors, lithium niobate, and optical glasses.

It has many polymorphic forms all based largely on octahedrally coordinated niobium atoms.  The polymorphs are identified with a variety of prefixes.   The form most commonly encountered is monoclinic H-Nb2O5 which has a complex structure, with a unit cell containing 28 niobium atoms and 70 oxygen, where 27 of the niobium atoms are octahedrally coordinated and one tetrahedrally.  There is an uncharacterised solid hydrate, Nb2O5.nH2O, the so-called niobic acid (previously called columbic acid), which can be prepared by hydrolysis of a basic solution of niobium pentachloride or Nb2O5 dissolved in HF. 

Nb2O5 is prepared by hydrolysis of alkali-metal niobates and alkoxides and the fluorides using base. Such ostensibly simple procedures afford hydrated oxides that are calcined.

Nb2O5 is attacked by HF and dissolves in fused alkali. 

Niobium pentoxide is used mainly in the production of niobium metal,but specialized applications exist for lithium niobate and as a component of optical glass.