What is the Strongest Permanent Magnet - Comparison of Neodymium, Ceramic, SmCo and AlNiCo Magnets?
What is the Strongest Permanent Magnet?
Companies frequently invest in industrial-grade magnets for magnetic separation and other purposes, yet many remain unclear which permanent magnet is the strongest.
Neodymium-iron-boron magnets, commonly referred to as NdFeB magnets, boast one of the strongest magnetic strengths available today due to their high saturation magnetization levels; this measures how strong physical pull strength they can reach.
Ceramic, or ferrite magnets, are strong magnets capable of withstanding higher temperatures without demagnetization.
Neodymium
Neodymium magnets are among the strongest permanent magnets on the market. Crafted of rare earth metals and more costly than their competitors, neodymium magnets are made to withstand even severe vibration. But children should beware as these powerful magnets may choke them! Most powerful neodymium magnets come from rare earth materials which only exist in small amounts on Earth's crust and do not form seams like tin or lead do. Mining these rare materials is difficult; most are imported from China which restricts their exports in order to prevent war.
N52 magnets are among the strongest grades and can lift steel spheres that weigh 1000 times their own weight, boasting 18 times greater magnetic energy than traditional ferrite magnets. Their strong magnetic properties come from their tetragonal Nd2Fe14B crystal structure which causes its 4 unpaired electrons in each neodymium atom to align in their respective f orbital subshells, giving the magnet high magnetic saturation levels and resistance to demagnetization.
NdFeB
Neodymium iron boron magnets (NdFeBs) belong to the rare-earth magnet family and offer high saturation magnetization while resisting demagnetization, making them suitable for various applications like automotive electric motors, sensors and other high-tech devices.
Sintered NdFeB magnets may be coated with nickel, copper or other metals to increase corrosion resistance; however, they remain vulnerable to corrosion in most environments as iron atoms within its structure may corrode and lead to permanent weakening or even loss of magnetic properties.
To prevent this from happening, magnets require a protective coating or surface finish to maintain magnetic integrity over time. NdFeB magnets may not be recommended in marine environments where salt spray and seawater could deteriorate their magnetic property over time; in such conditions ferrite or Samarium Cobalt magnets may be more appropriate; Samarium Cobalt magnets feature flatter curves for their temperature coefficient (Br), so their performance remains more consistent over a broader temperature range.
Ferrite
Ferrite magnets are ceramic magnetic materials composed of iron oxide and oxides of other metals. Due to their low magnetic field strengths and affordability, ferrite magnets have become popular choices for consumer products and other uses. Ferrite magnets can be formed into various shapes and sizes.
Ferrites differ from more costly rare earth magnets in that they're less susceptible to demagnetization and heat-induced demagnetization, meaning that they maintain their magnetism for extended periods. Ferrites are widely used as motor magnets.
Neodymium magnets produce stronger magnetic fields than their permanent magnet counterparts such as ferrite or alnico, as well as being more corrosion-resistant. Unfortunately, however, neodymium magnets must be handled carefully due to their attraction for steel objects, making them potentially unsafe for children or stored away from electrical devices as they can potentially cause injury if touched together or caught up in machinery - this makes TDK's range of neodymium magnets available in various grades a good place to start your search!
Rare earth
Rare earth magnets produce much stronger magnetic fields than their ceramic and alnico counterparts, making them particularly useful for applications such as lifting metals with magnetic force and using sweepers to pick them up. However, care must be taken in handling rare earth magnets as improper use could cause serious injury.
Rare-earth metals are ferromagnetic elements similar to iron but do not form seams, thus rendering them "rare." Used in green technologies due to being produced more efficiently than coal or copper, rare-earths are produced by China but exports may be restricted for political gain.
Neodymium alloyed with iron and boron produces one of the strongest permanent magnets available: NdFeB magnets are often called these powerful permanent magnets and can be formed into blocks, discs, rings, rods or cubes depending on your application needs. When combined with nickel-copper-nickel or samarium cobalt magnets for cost effectiveness.