Niobium is an element that in its pure form is a dull grey ductile metal. In the periodic table, niobium has the symbol Nb and the atomic number 41, and is considered a paramagnetic metal in group 5 of table. Niobium is the 33rd most common element in the Earth, but because of its density, it is estimated that the majority of niobium occurs in the Earth’s core. Niobium is most commonly found in two minerals: pyrochlore and columbite. Niobium has a very high melting point, but a very high density as compared with other similar metals. Niobium tends to take on a bluish hue after extended exposure to air.
History of Niobium
Niobium was first isolated as an individual element in 1801 by the British chemist Charles Hatchett, but was not named niobium at that time. The properties of niobium are quite similar to another element, tantalum, and the two elements were originally classified as the same element. In 1865, a German chemist named Heinrich Rose successfully noted the differences between niobium and tantalum, and gave it the name niobium, which was officially bestowed on the element in 1949.
Uses for Niobium
Niobium has a variety of uses due to its unique qualities. Niobium’s first commercial use was as light bulb filaments due to its high melting point, but was replaced fairly quickly with tungsten for this purpose. Niobium has some superconducting properties, and is also corrosion resistant. Niobium is used as an additive to steel alloys to improve its grain structure and hardness. This use was first discovered in the 1920’s, and are still in use today. These steels are often used in applications such as automobile frames. Niobium carbide is a hard, refractory, ceramic material. Due to these traits, niobium carbide is commercially used in cutting tools.
Niobium has extreme heat resistance, and niobium alloys were used in various thruster assemblies during the Apollo space missions. Niobium’s superconducting properties were discovered in the 1960s. These properties allow it to be used quite successfully for superconducting magnetic applications, and provides one of the deepest magnetic field penetration levels. These types of magnets are used for magnetic resonance imaging (MRI) systems or particle accelerators. The superconductivity of niobium is highly dependent on how pure the element is. Niobium has also been used as a component in multi-element superconducting alloys
Niobium does not react with human tissue, so it is often used in implanted devices, such as pacemakers, or for other items that touch the skin, such as jewelry.