Rare earth magnets are fascinating things, both in their capabilities and their history. Magnetism itself, or rather, the human discovery and understanding of magnetism, dates back to around 600 BC. Back then, Greek philosophers noted some peculiar properties of some natural ferrite stones. Aristophanes was the man who discovered the phenomenon of electrical charge, although we did not further our understanding of this for nearly two thousand years afterwards. It was finally around 1600 AD that the term “electric” was coined.
A Dr William Gilbert showed that there appear to be two separate electrical effects. It was he who explained the mystery of the compass – that it points along the Earth’s own magnetic field. Later still, in 1747, Benjamin Franklin showed that electrical charge is a result of two opposite forces interacting.
Rare earth magnets use unusual elements to produce a very strong magnetism. These include neodymium iron boron and samarium cobalt magnets, each of which has its own properties and ideal uses.
Many more ordinary kinds of magnet, such as alnico, have been replaced by high-strength rare earth magnets. Most ordinary kinds of magnet have much lower coercive force than their rare earth counterparts – they are low energy products. They may however have other properties, such as heat resistance, that make them still relevant to today’s needs.
The most common magnets you can find are known as ceramic or ferrite magnets. They use either strontium carbonate or a mixture of barium and iron oxide. They are available at much lower cost due to these elements being common in the world, unlike the aptly named rare earth magnets.