The History of Neodymium Magnets, Part Two
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Today, neodymium magnets are known for being the most powerful magnet and a highly sought out material for use in various applications. Because of this, it may surprise you to learn that neodymium magnets were not discovered until the 1980s. In this blog, we will discuss the history of the development of neodymium magnets.
As a whole, rare earth magnets alloys were not discovered or developed until the mid-to-late 1960s. Prior to this, the only magnets available were alnico magnets (composed of an alloy of aluminum, nickel, and cobalt) and ceramic magnets. Then, in 1966, the United States Air Force Material Laboratory discovered that the alloy YCo5 (an alloy of yttrium and cobalt) displayed exceptionally high magnetic anisotropy as well as unusually high coercivity. From here, samarium cobalt (SmCo) magnets were developed as the first rare earth magnet.
Samarium cobalt magnets held impressive strength, but researchers were still seeking a cheaper, more powerful permanent magnet material. After many efforts to develop such a material, two simultaneous discoveries finally occurred in 1984. Both the Sumitomo Special Metals Co in Japan as well as General Motor Co in the United States discovered the composition Nd2Fe14B—the neodymium iron boron magnet alloy still used today. While the two companies discovered this composition at the same time, the methods used were slightly different. The Sumitomo Special Metals Co used a process comparable to that used in the fabrication of samarium cobalt magnets. General Motor Co, meanwhile, used a slightly different procedure that was based on a rapid solidification technique. Both of these methods allow for large scale commercial production.
Neodymium iron boron magnets were immediately more popular than samarium cobalt magnets, largely due to the price difference between the two. Both iron and neodymium are significantly cheaper than cobalt and samarium, respectively. Additionally, neodymium is approximately four times more abundant than samarium cobalt. Still, samarium cobalt magnets are highly valuable for applications that require a greater tolerance of high temperatures and applications that require greater resistance to corrosion.