Why Samarium Cobalt and Neodymium Magnets are Called "Rare Earth" Magnets?

There are seventeen rare earth elements– fifteen of which are lanthanides and two of which are transition metals, yttrium, and scandium found with lanthanides and are chemically similar. Samarium (Sm) and Neodymium (Nd) are the two most commonly used rare earth elements in magnetic applications. More specifically, samarium and neodymium are light rare earth elements (LREE) in the cerium earth group. Samarium cobalt and neodymium alloy magnets provide some of the best force-to-weight ratios for industrial and commercial applications.

The relatively small and difficult to access ore deposits containing rare earth elements contributed to the initial naming of the seventeen elements. The term "earths" simply refers to naturally occurring mineral deposits. The historical scarcity of these elements made its namesake inevitable. Currently, China meets approximately 95% of global demand for rare earths – mining and refining around 100,000 metric tons of rare earths a year. The United States, Afghanistan, Australia, and Japan also have significant rare earths reserves.

The second explanation for rare earth elements being designated "rare earth" was difficulty in mining and refining processes, which was typically done by crystallization. The term "rare" is historically synonymous with "difficult" Because their mining and refining processes were not simple, some experts suggest the term "rare earth" was applied to these seventeen elements as a result.

Samarium Cobalt magnets and Neodymium rare earth magnets are neither prohibitively expensive nor in short supply. Their label as "rare earth" magnets should not be a primary reason to either select or discount these magnets from industrial or commercial applications. The potential use of either of these magnets should be carefully measured according to intended usages and variables like heat tolerances. The designation of magnets as "rare earth" also allows for a general categorization of both SmCo magnets and Neo magnets together when mentioned alongside traditional AlNiCo magnets or Ferrite magnets.