Rare earth magnets are perhaps some of the world's most powerful magnets ever found. They are permanent magnets that are developed from rare earth elements. While their magnetic attraction is very strong, they are by nature very brittle and corrosive, requiring them to be coated or plated with nickel or a like substance that will strengthen the magnet against chipping and breakage. There are two main kinds of rare earth neodymium or samarium-cobalt. Both of these magnets are made of alloys that are neither rare nor precious today; however, when the periodic table was in the process of being developed, the same alloys were considered both rare and precious in the day. The magnets have retained the name since that time.
Samarium-cobalt were the first rare earth magnets ever to be invented. This occurred in the 1970s, and since then, they have been used in a limited variety of ways. Due to their expensive production costs, and widely varied properties, they are only used in certain applications. To start, the alloy has an extremely high Curie temperature point. However, it is the weaker of the two families as regards magnetic attraction. In addition, these magnets are very prone to breakage and chipping; yet they are highly resistant to oxidation. Because of these qualities, and because of the high cost involved with making them, these magnets are mainly used in situations in which strong magnetic fields are needed at high temperatures. Neodymium were developed nearly a decade later, when stronger were needed for many of today's machinery. The magnets are strong, and very compact. They offer the most magnetic field strength of any on earth. However, like their Samarium-cobalt counterparts, they are prone to splintering, chipping, breaking, and corrosion. Because of this, they are usually coated with either nickel plating or a copper-nickel combination to protect the actual. Sometimes, other metals, polymer, or a lacquer are used instead. easier to produce than the other rare earth, thus driving the cost of production down and making them cheaper than the samarium-cobalt. Neodymium are used in much of today's modern machinery, including cordless tools, fasteners, computer parts, and even magnetic building toys.
Rare earth magnets have helped to usher in a new era because of their amazing strength, their high resistance to temperature, and their wide variety of uses. The magnet you will need completely depends on what you will need the magnet for. Weaker in field strength, the samarium-cobalt magnets are highly valuable in situations that need magnets to endure high temperatures during use. Neodymium magnets, however, are much stronger and less expensive, giving them a wider range of uses for today's technology. Knowledge of both kinds of magnets will allow you to find the perfect magnet for your needs.