Earth magnets can be found throughout the world, and can be used in thousands of ways. The magnetic characteristics are high, while their electrical resistance and corrosion resistance is lower. Some of these earth magnets are used in their pure form, while others are combined with additional materials. Below are just a few of the more popular kinds.
Ceramic
Also known as Ferrite, this magnet is a mixture of iron oxide with strontium carbonate. Both compounds are found in abundance, and this makes them cost less than other magnets. The ceramic magnet is made by pressing and sintering the metal. The material is brittle, so a diamond wheel is often used to grind it. The anisotropic method is best used with ceramic to provide the highest magnetic energy properties.
Alnico
This is a combination of aluminum, cobalt, nickel, and other assorted elements. These are temperature stable, and resistant to shock demagnetization. The alnico magnet can be produced from casting or sintering. Casting allows for more design choices, but sintering helps preserve the characteristics of the metal. This magnet is used at times to replace ceramic magnets, as it is stronger.
Samarium Cobalt
Resistant to oxidization, this element has more strength of temperature, and higher magnetic properties than alnico or ceramic. First discovered during the 70's, samarium cobalt was soon used in multiple applications. Able to withstand temperatures of over three hundred degrees Celsius, this is one of the most rare of earth magnets. This magnet can not be formed by sintering, as it will become too brittle, and likely chip or break.
Neodymium Iron Boron
This magnet shares some characteristics with samarium cobalt, but is more easily oxidized and less resistant to temperature. Magnets made of neodymium iron boron cost more to make, and therefore are used in less applications. Since it is highly corrosive, it must be combined with additional materials.
Injection Molded
Made out of magnetic powders combined with a resin composite, these earth magnets are formed in a molding process. The energy varies depending on the materials used during fabrication. This is one of the best magnets for forming shapes that cannot be achieved with hard metal. However, since they are made from powder, there are limits to how strong they are, and how much load they can support.
Flexible
Similar to injection molded, earth magnets of the flexible variety are just that, flexible. They are most often designed in strips, or flat sheets. The strength of this magnet depends on which magnetic compounds are used to make it. The powder it is made from is combined with an adhesive. This is necessary to hold the magnet together. The most common form of binder for flexible magnet production is vinyl.
Children’s toys were simpler back before video games, iPods, iPhones, iPads, laptops, social networking, and the Internet. Back then, children often used everyday objects to make their own toys and entertain themselves. One thing kids used were earth magnets, composed largely of mercury.
Children that played with earth magnets had more entertainment, challenge, and power than modern technology offers today at a fraction of the cost: they had magnetism and electricity. The child who had a magnet held true magic in his hands. It could be made to dance and spin, and the child who controlled the magnet also had control of something even more exciting: electricity.
This child could impress his friends by professing that generating electricity was easy. He could astonish his friends by explaining that magnetism is generated by electrons, which have a negative charge. These negative particles spin around the molecules in iron and create the negatively charged pole. This negative pole will become magnetic when it gets around its opposite a positively charged pole. Then, the best part of the demonstration, generating this magnetism by rubbing errant pieces of iron together to create earth magnets and proving the science lesson he had just explained.
Whether his friends were impressed or not, this young scientific magician had discovered his passion using regular, everyday items he could find around town to create earth magnets. He used his passion for all sorts of things making black dust made of steel inside pictures move, attacking Mom’s fridge with homemade magnets, and proving to Dad that his silver coin collection was rubbish because real silver is not magnetic like Dad’s fake silver coins.
As he got older, his passion for earth magnets did not diminish. He founded a company that specialized in creating magnets. His business reached world-wide proportions as it utilized magnetic power. Meantime, he started a family. When it came time to start buying toys for his son, he gave in to the changing times and bought him an iPhone. He started sharing his passion with his son, explaining all about how magnets helped his phone operate correctly, but his son was so busy texting he did not even hear him.
Kids like this one who played with earth magnets have grown up and helped create some of the most popular electronic devices today. Electromagnetism is what makes so many of your favorite electronics work, from televisions to computers to cell phones. It also has allowed the invention of brushless DC motors, modernized welding equipment, various timing systems in cars. The new generation of kids are so busy trying to beat the latest video game or figure out the latest gadget that they are missing out on one of the most essential experiences of being a kid: learning about the magical world around them and experimenting to see what they can make this world do. Do not let this be true of your children. Teach them to appreciate simpler entertainment, like creating earth magnets from iron and steel; maybe by doing so, you can ensure that the next generation invents even more uses for earth magnets and electromagnetism.
