Which combination is commonly used in rare earth magnets according to the material?

• A. Neodinium, boron, iron
• B. Neodymium, iron, cobalt
• C. Cerium, boron, aluminum
• D. Lanthanum, boron, copper

Answer: (A)

Rare earth magnets achieve their strongest performance when they are made from neodymium, iron, and boron. This combination forms a Nd2Fe14B phase that packs a very high magnetic energy density, so you get a powerful magnet in a compact size and good resistance to demagnetization. That’s why neodymium-iron-boron magnets are the standard choice for many high-strength applications, from motors and generators to hard drives and headphones. The other options either substitute boron with other elements or rely on different rare-earth alloys, which don’t deliver the same level of strength as Nd-Fe-B magnets.