Introduction
Due to their extraordinary magnetic and mechanical properties, Rare Earth-Iron-Nitrogen (RE-Fe-N) permanent magnets have been extensively applied in various industrial and medical applications. RE-Fe-N magnets are a type of permanent magnets made of Rare Earth (RE) elements, Iron (Fe) and nitrogen (N). The RE-Fe-N magnets possess high coercivity, high-temperature stability and electrical resistance, making them ideal for numerous technical applications such as electric motors and refrigeration systems.
History
The RE-Fe-N magnets were invented in the early 1980s by a team of researchers at the Technical Institute of Advanced Manufacturing at the Madrid Polytechnic University. The research team combined the rare-earth element neodymium (Nd) with iron (Fe) and nitrogen (N) to create an ultra-strong magnetic material. They named the magnet “Neodymium-Iron-Nitride,” or Nd-Fe-N for short.
The scientists hypothesized that the combination of these elements would yield a material that could be used in the construction of a variety of permanent-magnetized devices, such as motors and refrigeration units. The project took a considerable time to complete, but their results have revolutionized the manufacturing of permanent-magnet devices.
Characteristics
RE-Fe-N magnets have much higher coercivity and remanence than traditional permanent magnets such as alnico and ferrite magnets. Coercivity is a measure of the lowest external magnetic field at which the magnetism of a material is completely reversed and its magnetic properties are completely destroyed. The higher the coercivity, the higher the resistance to external magnetic fields. The remanence is the magnetic energy stored in a material, and RE-Fe-N magnets have an incredibly high remanence.
The RE-Fe-N magnets are also much more reliable in high temperature conditions. The high-temperature melting point of the RE-Fe-N alloy is much higher than that of other permanent magnet materials, therefore making them suitable for applications in areas with higher temperatures.
Applications
RE-Fe-N magnets are primarily used in electric motors and other related applications. The high coercivity enables them to maintain a permanent magnetic field even when exposed to high levels of heat generated during the operation of an electric motor. This is why RE-Fe-N magnets are the standard for electric motors used in the automotive and aerospace industries.
The high remanence of RE-Fe-N magnets also makes them ideal for use in medical devices, such as Magnetic Resonance Imaging (MRI). Because of the high remanence, the RE-Fe-N magnets can store a high amount of energy even at very low temperatures. This makes them ideal to create a stable and powerful magnetic field used in medical imaging. RE-Fe-N magnets are also used in loudspeakers and other electronic devices.
Conclusion
Rare Earth-Iron-Nitrogen (RE-Fe-N) permanent magnets are extremely versatile and high performing magnets made of the combination of Rare Earth (RE) elements, Iron (Fe) and nitrogen (N). Due to their high coercivity and remanence, these magnets are a standard choice for electric motors used in the automotive and aerospace industry and for other applications in medical imaging, loudspeakers and other electronic devices. The history, characteristics, and applications of RE-Fe-N magnets have been discussed in this article.
