Magnetism matters. From navigating the seas by compass to navigating your neighborhood by smartphone, none of it would be possible without harnessing magnetic fields. Without getting too abstract, magnetism matters when it comes to identifying and moving metal at a scrapyard. But with the power it takes for a magnet on a crane to lift a hunk of steel, how does that all that magnetic energy not cause the world to go haywire? The answer lies in the difference between temporary and permanent magnets. Let’s take a closer look.
Plenty of metals are inherently magnetic, iron being chief among them. Nickel and cobalt also have inherent magnetic properties, though if you try to use a five-cent piece as a magnet, you’ll be disappointed—our own nickels are three times more copper than nickel. The lanthanide series of metals, also known as rare-earth metals, are also inherently magnetic. You would find these metals inside your smartphones and even your earbuds. We can call these metals permanent magnets because they create and maintain their own magnetic fields without any assistance.
Sometimes a little assistance is necessary. Metals that don’t have their own magnetism can still become magnetized by entering the presence of an existing magnetic field. However, when the field is taken away, they lose their charge. We call these temporary magnets. Temporary magnets can be made of numerous metals and alloys, such as lead or aluminum, but often the same iron and nickel with weaker permanent charges of their own. You can see temporary magnetism in action at your own desk. Attach a paper clip to a magnet, and then chain more paper clips together, not by fastening them but simply by having them touch. Remove the base magnet and watch the paper clips lose their magnetism and tumble apart.
Some temporary magnets have much more important uses than amusing yourself at your desk. Electricity and magnetism go hand in hand. Electric currents create magnetic fields. We’ve harnessed this property to create magnets that have even more power than permanent ones. These electromagnets rely on an electric current to generate their magnetic charge. When the current is switched off, they lose their magnetism. A scrap yard magnet is a common example of an electromagnet, hoisting permanently magnetic metals, such as iron, from the scrap heap and separating them from non-ferrous (non-iron) metals of value.
This should help you understand permanent and temporary magnets and the differences between them. Because of the ability to control their magnetism, temporary magnets have far more industrial applications than their permanent counterparts. Though the magnetism may be temporary, the electromagnets of Moley Magnetics are certainly built to last.