Carbonyl iron is a highly pure (97.5% for grade S, 99.5+% for grade R)

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

, prepared by chemical decomposition of purified

iron pentacarbonyl Iron pentacarbonyl, also known as iron carbonyl, is the compound with formula . Under standard conditions Fe( CO)5 is a free-flowing, straw-colored liquid with a pungent odour. Older samples appear darker. This compound is a common precursor to ...

. It usually has the appearance of grey powder, composed of spherical microparticles. Most of the impurities are

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon mak ...

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

, and

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

BASF BASF SE () is a German multinational chemical company and the largest chemical producer in the world. Its headquarters is located in Ludwigshafen, Germany. The BASF Group comprises subsidiaries and joint ventures in more than 80 countries ...

invented carbonyl iron powder in 1925 and claims to be the world's leading producer. In 1934, BASF was also involved in the development of the very first magnetic tapes used by the AEG Magnetophon tape recorder. Carbonyl iron became the first magnetic recording oxide (although quickly replaced in 1936 by iron oxide). In

electronics The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...

, carbonyl iron is used to manufacture magnetic cores for high-frequency coils and in production of some ferrites. Spherical particles manufactured of carbonyl iron are used as a component of the radar absorbing materials used by the military, in stealth vehicles, for example. Other uses are in

powder metallurgy Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders. PM processes can reduce or eliminate the need for subtractive processes in manufacturing, lowering material losses and ...

metal injection molding Metal injection molding (MIM) is a metalworking process in which finely-powdered metal is mixed with binder material to create a "feedstock" that is then shaped and solidified using injection molding. The molding process allows high volume, ...

, and in various specialty products. Powdered cores made of carbonyl iron have high stability of parameters across a wide range of temperatures and magnetic flux levels, with excellent Q factors between 50 kHz and 200 MHz. A popular application is in broadband

inductor An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a c ...

s, especially in high-power applications. In pharmaceutics, carbonyl iron powder is used to treat

iron deficiency Iron deficiency, or sideropenia, is the state in which a body lacks enough iron to supply its needs. Iron is present in all cells in the human body and has several vital functions, such as carrying oxygen to the tissues from the lungs as a key ...

and as an iron dietary supplement. In 2017 carbonyl iron powder was reported as an effective reductant for aromatic nitro groups in water, an important reaction used in the synthesis of pharmaceuticals. Particles of carbonyl iron (20–40%) suspended in a carrier fluid (60–80%) are used as a magnetorheological fluid.

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{{Refimprove, date=December 2007 Iron

See also

References