IQS Newsroom Articles on Rare Earth Magnets
Rare Earth Magnets
For applications that require exceptionally strong magnets for holding, separating
and lifting, rare earth magnets are by far most effective. There are two main
types of rare earth magnets: neodymium magnets, which are composites of the
rare earth element neodymium, iron and boron; and samarium magnets, which are
composited from cobalt and rare earth element samarium. Rare earth elements
are also called lanthanoids and are found within certain types of oxide-rich
minerals within the Earth's crust. Lanthanoid elements have partially
filled outer f electron shells which are the source of neodymium and samarium's
exceptionally powerful magnetic fields. The relative scarcity of mineral deposits
containing neodymium and samarium combines with the long and costly process
of extracting rare earth elements from naturally-occurring ores, making neodymium
magnets and samarium cobalt magnets costly in comparison to non-rare
earth magnets.
Electro magnets, alnico magnets and ceramic (ferrite) magnets are used extensively in automotive, medical, industrial and
aerospace applications; rare earth magnets do the work that weaker ferrite
and alnico magnets cannot. Applications for neodymium and samarium magnets
are almost limitless, and their functions are often more complex than their
weaker relatives. Aside from ordinary physical work such as holding, lifting
and separating, rare earth magnets are crucial components in electric motors,
servo motors, DC brushless motors, wind turbines, TV monitors, welding equipment, power meters,
engine timing systems, ignition timing systems, linear actuators, sensors,
vending machines and other equipment.
Neodymium magnets are both stronger and more affordable than samarium cobalt
magnets and are therefore more widely used. Magnetic permanence under conditions
such as vibration, corrosion, electric fields and heat is a crucial factor
for magnets used in industrial, automotive and medical equipment, and although
neodymium composites have good magnetic permanence under most conditions, they
lose their magnetism under corrosion and relatively low temperatures (200 degrees
Celsius). Samarium cobalt magnets retain their magnetism under higher temperatures
than any other magnet (over 550 degrees Celsius). Consequently, samarium magnets
are used mainly in applications which require high heat resistance. Neodymium
magnets are easily chipped or cracked, so they are often given a protective
nickel or other metal coating.
As the automotive industry explores petroleum alternatives, the rare earth
magnet industry has seen a sharp rise. Rare earth magnets - mainly neodymium
magnets - are crucial in most electric motors, and concern has already
been raised regarding lanthanoid ore shortages. However, medical, aerospace,
electronics, automotive and wind power industries have barely begun to harness the natural
power of rare earth magnets. With looming petroleum shortages, rare earth magnets
are rising as a potential part of alternative energy solutions.