A good permanent magnet should produce a high magnetic field with a low mass, and should be stable against the influences which would demagnetize it. The desirable properties of such magnets are typically stated in terms of the remanence and coercivity of the magnet. 40pcs Magnets Disc Countersunk Permanent Magnet Fastener Magnets 12mm D Disc Countersunk Pe12mmX3mm,Magnets With Holes,Countersunk Hole 4mm (Disc:12x3-4mm) 4.4 out of 5 stars 235 $14.99 $ 14. Permanent magnets are limited by the structure of the material. And the strongest magnetic field of a permanent magnet is about 8,000 gauss. The strongest magnets here at the Magnet Lab are 450,000 gauss, which would be almost 50 times stronger than that. There are two main different types of magnet, permanent magnets and electromagnets. A permanent magnet stepper motor is a compatible and highly efficient device that has numerous applications. Since the rotor is made of permanent magnets, it does not need any external excitation which makes it very useful in applications such as toys, small. Magnets are used in many different applications given their inherent strength in relation to mass and weight. Electromagnets, because they can be turned off and on, are used in powerful pieces of equipment and vehicles, such as magnetic-levitation, or maglev, trains.However, permanent magnets.
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use of ferrites
In magnetic ceramics: Permanent magnets
Hard magnetic ferrites are used as permanent magnets and in refrigerator seal gaskets. They also are used in microphones and speaker gaskets. The largest market for permanent magnets is in small motors for cordless appliances and in automobile applications.
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magnetic properties
cobalt
In cobalt processing: Magnetic alloys
The best permanent magnets contain a substantial quantity of cobalt.
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hysteresis loop
In magnetism: Remanence
A good permanent magnet must have a large spontaneous magnetization in zero field (i.e., a high retentivity) and a high coercive force to prevent its being easily demagnetized by an external field. Both of these imply a “fat,” almost rectangular hysteresis loop, typical of a hard magnetic…
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rare-earth elements
In rare-earth element: Permanent magnets
The most prominent rare-earth intermetallic compound is Nd2Fe14B, which is ferromagnetic and, with proper heat treatment, becomes the hardest magnetic material known. Hence, this intermetallic compound is used as a permanent magnet in many applications. Its main uses are in electric motors (e.g.,…
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In rare-earth element
…an electrical traction motor, with permanent magnets containing rare-earth elements. In addition, modern media and communication devices—cell phones, televisions, and computers—all employ rare earths as magnets for speakers and hard drives and phosphors for optical displays. The amounts of rare earths used are quite small (0.1–5 percent by weight, except…
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In rare-earth element: Abundance, occurrence, and reserves
…as large SmCo5- and Nd2Fe14B-based permanent magnets. All of these materials hold 25–30 percent by weight light lanthanides—much more than even the best rare-earth-containing ore (see below). However, the majority of consumer electronic devices contain only small amounts of rare earths. For example, a hard drive’s spindle magnet contains only…
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What Objects Use Permanent Magnets
Actually... this isn't a bad instructable. If you want to make a stronger permanent magnet you should induce an electrical field around the fork while it cools. Part of what causes a magnet is the electron vectors in the iron atoms. The more vectors that are aligned in the solid metal structure, the stronger the magnet will be. Heating the fork allows the iron atoms to come into alignment. if you 'stroke' it while it cools, more electron vectors will be aligned correctly. This works especially well if you have some way of rapidly cooling the fork.