Neodymium magnets are some of the most commonly used household items. They’re found in so many everyday appliances from air-purifiers to speakers, and even in some toys. If you’ve ever seen a fridge magnet or 3D printed object with a neodymium magnet, it’s because these small but powerful magnets are very common. Even though they are so common, few people know about how neodymium magnets lose their magnetism. Most people assume that once they lose their first layer of coating, that’s it; however, that is not the case.
Neodymium loses its magnetism faster than other types because they have larger domains. A domain is one of the two major characteristics of all ferromagnetic materials such as steel and iron (the other being embrittlement). Like any other material, ferromagnetic materials lose their magnetism when they reach an atomic limit called Curie Point or saturation point.
The Curie point is the temperature at which a material becomes saturated and begins to lose its magnetic qualities as its crystal structure changes from stable magnetic order to disordered metallic ions with no net electric moment per atom. The Cure Point for NdFeB is 753°C (1,346°F). For this reason neodymicity type materials become less magnetic when exposed to higher temperatures in the range of 800°C – 1,000°C (1,500°F
What is Neodymium?
Neodymium is one of the most common ferromagnetic materials. It’s a rare earth metal, which is sometimes referred to as “rare” because it’s not in huge supply.
Rare earth metals are very important in electronics, but they can only be found in small quantities on Earth and are not mined here. The United States has no large deposits of rare earth metals, so we must import them from other countries that do have a lot of these minerals. Neodymium magnets are made from neodymium and boron. They’re used for their high magnetic strength and low cost, making them very popular with hobbyists and industry professionals.
What causes Neodymium Magnet to lose its magnetism?
The Curie point is the temperature at which a material becomes saturated and begins to lose its magnetic qualities as its crystal structure changes from stable magnetic order to disordered metallic ions with no net electric moment per atom. The Cure Point for NdFeB is 753°C (1,346°F). For this reason neodymicity type materials become less magnetic when exposed to higher temperatures in the range of 800°C – 1,000°C (1,500°F)
How to Detect if a Neodymium Magnet has Lost Its Magnetism?
To detect if a neodymium magnet has lost its magnetism, you must first remove the magnetic coating and find out what type of material it is by testing on a magnetometer. If you want to test this out for yourself, try it out with a non-magnetic object like a fork.
Ways to Preserve Neodymium Magnets for a Long Time
This is where neodymium magnets lose their magnetism, so it’s important to know how to preserve these magnets for a long time.
One way you can do this is by coating the magnet with other ferromagnetic materials like copper, nickel, or iron. This will make the neodymium magnet as strong as any other ferromagnetic material. Another way is to use a magnetic fluid that is specially designed for neodymium magnets. One such fluid is magnetic oil and this prevents oxidation from occurring on the magnet surface and keeps it looking new for a very long time. Lastly, you can use expensive urethane coatings that are resistant to corrosion and oxidation.
So, if you want to keep your neodymium magnets around for a very long time, it’s important that they’re coated or preserved in some way so they maintain their magnetic strength and don’t lose their magnetism too quickly.
Conclusion
Neodymium magnets are powerful magnets that are used in many industries today, ranging from medical devices to electronics. They are an ideal choice for their high performance and longevity. But, Neodymium magnets can lose their magnetism over time.
This is why it is important to know how to detect if a Neodymium Magnet has lost its magnetism so that you can ensure that your product is still functional. Here are some ways to preserve Neodymium Magnets for a long time.
