Niobium (Nb) is a light grey transition metal in the fifth period and part of the vanadium group. In nature, it occurs closely-related with tantalum. This is why, for a long time niobium and tantalum have been mistaken to be only one instead of two separate elements.

The English chemist Charles Hatchet first identified Niobium in 1801 in a mineral sample from Connecticut, United States. He therefore named the element “columbium” in relation to “Columbia”, the female national personification of the United States. Then, a few years later, in 1844 Heinrich Rose, a professor in Berlin, independently concluded that niobium and tantalum are two different elements. Unaware of its preceding description he called the element niobium (from Greek mythology - “Niobe”, daughter of “Tantalus”) in order to emphasize the similarities in appearance and occurrence with tantalum. Finally, about 100 years later, in order to make an end to this naming confusion, the International Union of Pure and Applied Chemistry (IUPAC) officially adopted the name niobium for the 41st element in 1950. Yet until today, some metallurgist and metal societies still use the original American name columbium.

Niobium is ductile and paramagnetic. With its high melting point of 2477 °C it belongs to the group of refractory metals, while it stands out in this group with a comparably low density of 8.57 g/cm3. In addition, it is corrosion-resistant, forms dielectric oxide layers and is a superconductor at cryogenic temperatures. In size, the niobium atom is near to identical with the tantalum atom. This is why their chemical properties are so comparable. While in direct comparison the corrosion resistance of niobium is lower, its higher availability and therefore cheaper pricing make it an appealing alternative for less demanding applications.

Approximately 90% of the niobium mined today is used as a microalloy (<0.1%) in high-grade structural steel. Here it forms niobium carbide and niobium nitride, thereby increasing the toughness, strength, formability and weldability. The second largest application is in superalloys for the use in i.e. jet engine components, gas turbines or combustion equipment. Its corrosion-resistance makes it attractive for the use as a thin film back contact for ITO touch displays. As an addition to Ti-Al sputter targets, niobium increases the high-temperature strength of the deposited thin films hard coatings. In addition, niobium is physiologically inert and is therefore frequently used in prosthetics and implant devices.