Magnets have captivated our curiosity for centuries, from their early use as compasses to harnessing their energy for countless inventions and functions, including use in your cell phone, household appliances, and new and emerging technologies. Their elusive nature even appears in classic literature as Mary Shelley calls earth's magnetism and its magnetic poles "the wondrous power" in her novel Frankenstein (1818). Magnets and the physics behind them continue to fascinate us and we are ever curious and ever eager to find new uses and applications for them. Magnets are complex materials and in order to match the best magnet with an intended application, it's important to understand the various types of magnets and their unique properties and characteristics.
A magnet is made up of a combination of many materials that creates an invisible magnetic field. The material then attracts to ferrous material (containing iron) and repels same-pole magnets. A magnet has at least two poles, and when cut in half, those poles replicate themselves, so the new magnet also has a north and south pole. Some magnets, such as flexible magnetic material, even have multiple poles. The type of magnet determines its strength and ability to be magnetized or demagnetized. A magnet’s pole orientation affects how it inerracts with other magnets or ferrous surfaces.
Since the Earth’s core is primarily made up of iron, a strong magnetic field surrounds our planet, protecting us from harmful solar wind and creating visually astounding lights in the sky called an aurora. The Northern Lights or Aurora Borealis is the most well-known occurrence of this phenomenon and is a visual representation of the strong magnetic activity our planet produces and experiences.
Magnets are also constantly at work in our daily lives. Magnets are unseen but integral parts in our electronics, credit cards, appliances, and public transit rail lines.
Magnets take on many different appearances and the various types that exist all have their unique attributes and uses.
· Neodymium magnets, often called “rare earth magnets”, are the strongest on the market and are so named because the materials that undergo complex processing are themselves not found in high concentrations, thus making mining operations and resources for final treatment quite involved and expensive. Neodymium magnets are brittle and so they are either plated or coated to protect them.
· Ceramic magnets are also brittle, but not as strong as neos. They are gray in appearance and are the most commonly used magnet in novelty products. They certainly hold their own in terms of strength and are very affordable.
· Flexible magnets are the most versatile in that they can either act as a backing to a product or be directly printed to make a flexible magnetic image or sign. Flexible magnet material is created by mixing ferrite powder with a rubber polymer.
"The Wondrous Power" (Mary Shelley's Frankenstein)