How Can a Permanent Magnet Be Destroyed?
How Can a Permanent Magnet Be Destroyed?
Permanent magnets rely on their crystalline structure and electron polarities to maintain their magnetic properties, but any alteration to them by extreme heat or other magnetic fields could cause it to lose its magnetism and become ineffective.
Hard ferromagnetic materials such as neodymium, ferrite and alnico are especially vulnerable to damage by magnetic fields; fortunately, however, even damage caused by these sources can be reversed using appropriate techniques.
Permanent magnets typically retain their magnetic properties until heated to temperatures beyond their maximum use temperature for that material type. But all materials, regardless of material, tend to lose magnetic power with temperature increases due to thermal motions jiggling atoms out of alignment, shifting magnetic domain walls out of position and ultimately leading to reduced magnetic performance.
Cooling magnets will cause its atoms to become more stable, and domain walls to have difficulty switching their directions - leading to loss of magnetism or inability to attract or repel other magnets, or even itself.
Some types of permanent magnets, like those made from neodymium rare earth materials, possess higher coercivities than older materials like alnico or ferrite and are therefore less vulnerable to heat-induced demagnetization. Therefore, it's crucial that they be stored correctly with their north poles together and their south poles separated - this way preventing demagnetization due to being stacked together or placed into hot water containers.
Although most magnets can withstand incredible amounts of heat, their magnetic strength may deteriorate if exposed to water and corrosion. This is because permanent magnets contain high concentrations of iron (around 60% in neodymium magnets), making them vulnerable to rusting and corrosion when in damp environments. For this reason, magnets are usually coated before use with nickel, stainless steel, PTFE epoxy rubber coatings - usually nickel.
Corrosion can alter the shape of an object, altering how strongly it attracts to magnetic fields. However, if corrosion damage is limited to only a thin layer on its surface it's likely that its magnetism will remain. Magnetic fields have also been shown to influence metal corrosion by altering electrode kinetics and mass transport , potentially increasing or decreasing corrosion rates depending on its direction and magnitude.
Magnets may lose their magnetic fields if exposed to blunt force, as a sudden shock alters its volume, which then impacts how its North and South poles are aligned.
As with radioactive elements, magnets eventually lose their radiation over time. Once a magnet reaches its Curie temperature, its structure has changed irreparably, and remagnetization cannot take place.
Therefore, magnets are susceptible to being destroyed if dropped, struck with something, or even hit with a hammer. The best way to safeguard against this damage is through proper storage; to do this safely you should stack your magnets together in piles (with their same orientation), avoid keeping them near metal objects, protect from extreme temperatures, water or humidity conditions and consider investing in demagnetization technology - an electric current is applied through demagnetizer tools in order to alter their atomic makeup and change its magnetic makeup over time.
Heat, blunt force or rough handling are all effective means of dismantling a magnet's magnetic field, disrupting domain alignment and randomizing their orientation until they no longer produce an overall magnetic field.
Demagnetizing magnetic material requires heating it past its Curie point temperature; this will untie magnetic dipoles from their ordered orientation and destroy long-range order of magnetism.
Magnets generally attract and repel each other depending on their respective north and south poles; one magnet's north pole may attract its counterpart's south pole, while vice versa. However, this effect will dissipate once separated from each other.