What are Rare Earth Magnets?

Rare earth magnets are extremely powerful magnets made from rare earth elements. The incredibly strong magnets are used in a variety of industries, and they are also employed by magicians to create illusions and similar tricks. Many scientific supply companies sell rare earth magnets, and they can also be found inside a number of products including speakers and computers. They are also often included inside kits for young scientists, or for people who are interested in exploring the properties of magnetism.

The term “rare earth elements” is used to describe sixteen elements on the periodic table, including ytterbium, cerium, praseodymium, neodymium, lanthanum, and samarium. These elements were originally believed to be quite rare, which is why they were grouped together under that name. The first of these elements was discovered in the 1800s, and later scientific advances indicated that some of these elements were actually not so rare after all. These elements have a number of interesting properties which make them a topic of study by scientists, and their potential use in magnets is one of these properties.

These elements are alloyed with other elements such as iron and boron to make rare earth magnets, which are usually identified by the primary rare earth elements they contain, as is the case with neodymium magnets. The resulting magnets have a very intense magnetic field which greatly exceeds the fields generated by more common magnets. In addition, they are considered permanent magnets, although some rare earth magnets will lose their magnetic fields at high temperatures. Some are also quite brittle, unfortunately, which means that they need to be used with care, as they can break apart with explosive force.

Two well known examples of rare earth magnets are neodymium magnets and samarium-cobalt magnets. Neodymium magnets are among the strongest of all magnets, and they are relatively affordable, making them very popular. Samarium-cobalt magnets are more brittle and expensive, but they are also suitable for use at high temperatures, since they will not lose their magnetism. This trait makes them popular in industrial manufacturing.

Because rare earth magnets are so strong, it is important to be careful around them. They can interfere with the function of medical devices such as pacemakers, in addition to wreaking havoc on electrical components. The magnets can also pinch fingers or cause damage to possessions, thanks to their powerful magnetic fields which will attract metal objects. As a general rule, the bigger the magnet, the bigger the risk, and people should be careful when they around larger rare earth magnets and big metal objects.

Rare earth magnets are composed of alloys of rare earth elements, primarily neodymium (Nd), samarium (Sm), and sometimes dysprosium (Dy) or praseodymium (Pr). Neodymium magnets, made from an alloy of neodymium, iron, and boron (NdFeB), are the strongest and most commonly used type of rare earth magnet.

They are called 'rare earth' magnets because they are made from the rare earth elements, which are part of the lanthanide series on the periodic table. Despite the name, these elements are relatively abundant in the Earth's crust, but they are difficult to mine and refine, which makes them 'rare' in terms of accessibility.

Rare earth magnets are significantly stronger than other types of magnets, such as ferrite or alnico magnets. They have higher remanence, which is the ability to retain a high magnetic field, and greater coercivity, meaning they can withstand demagnetization better. This makes them ideal for applications requiring compact yet powerful magnets.

Rare earth magnets are used in a wide range of applications due to their strength and compact size. They can be found in consumer electronics like headphones, smartphones, and computer hard drives, as well as in electric motors for hybrid and electric vehicles, wind turbines, and various medical devices such as MRI machines.

Yes, the production of rare earth magnets involves mining, which can lead to significant environmental damage if not managed responsibly. The extraction and processing of rare earth elements can result in toxic waste and pollution. Efforts are being made to develop more sustainable extraction methods and recycling of rare earth magnets to mitigate these concerns.

Rare earth magnets can lose their magnetism if they are exposed to high temperatures, physical damage, or corrosive environments. However, under normal conditions, they are very stable and can retain their magnetic properties for decades. Neodymium magnets, for example, are estimated to lose less than 1% of their magnetism over a period of 10 years.