Where Magnets Come From? -Everything You Need To Know!
Magnets are an amazing substance – they are used in making all kinds of things such as cars and computers. You’ve probably been wondering what exactly a magnet is – what is it made of? Where does it come from? The answers to those questions depend on whether you’re talking about man made magnets or natural magnets. Naturally occurring earth magnets include Lodestone, which naturally attracts iron.
Most magnets, however, are man made. Ferro-magnetic materials, which include iron, nickel, cobalt, neodymium, and samarium, can be made magnetic by exposing them to a magnetic field, mainly by using electric currents. Magnets that are created in this way only remain magnetic for as long as the electric current is on. If it is switched off, then their magnetic properties subside. This is the polarization process. But before we get into the the different types of magnets and magnetism, let’s first check out 11 amazing facts about ferrous materials as we demystify electrical fields, magnetic poles, and objects that produce electrical charges!
11 Magnet Facts
Interested in learning more about magnets and electricity? Then we are sure that you’ll love these interesting magnet facts:
- The ancient greeks discovered the first magnetic material over 2500 years ago.
- Two Japanese scientists named Dr Yogoro Kato and Dr Takeshi Takei accidentally discovered the first man-made magnet in the 1930’s.
- Magnets can now be found in common household items such as bags, purses, refrigerators, cars, and computers.
- Magnets are used to help equip hidden GPS trackers on the outside of vehicles so people can catch cheating spouses, teenagers speeding, and employees misusing company vehicles.
- Cows are sometimes fed magnets, which can attract any small nails and wires that the cow may have accidentally eaten which could damage it’s organs.
- Gigantic magnets are used in construction work. Cranes use these huge magnets to pick up metal objects.
- High-speed trains use electromagnets to run. The magnets cause the train to float above its track, which increases its speed.
- Some animals and bacteria have magnets present in their bodies. It serves different purposes, scientists suspect that pigeons have a magnetic sense that guides them home.
- The earth is a giant magnet. That’s right, its core is molten iron, which is always churning and creates an electromagnetic field around the planet.
- Saturn, Jupitor, Neptune, and Uranus all have magnetic fields, similar to earth.
- Roller Coasters also use magnets to push the carts along the track.
Different Types Of Magnets
Permanent magnets are made of materials that retain their permanent magnetism to a certain degree. These magnets have a magnetic field surrounding them, which is made of electrons that spin in the same direction. When another strong magnetic substance enters this magnetic field, the substances become magnetized and attach to each other.
Permanent magnets are not all made the same. They can lose their strength when heated to a certain temperature called the curie temperature. Different ferromagnetic substances have different curie temperatures.The heat of the curie temperature causes the electromagnetic field to spin out of alignment, which disrupts the magnetic forces. However, a magnet can actually be re-magnetized if the temperature is returned to normal and it is put through the process of polarization. Handling magnets with care is important, as dropping or damaging their exterior can also hurt the magnetic properties.
Neodymium Iron Boron Magnets
Neodymium Iron Boron magnets are the strongest form of permanent magnet. They are a type of rare-earth magnet, which means they are made of alloys of rare-earth metals. These metals include Neodymium (Nd), iron (Fe), and boron (B), which come together to form NdFeB in chemical terms. They are used to manufacture many modern products, including hard disk drives, magnetic fasteners, and computer products.
Neodymium Iron Boron magnets are considered the strongest type of magnet because it’s very hard to demagnetize them. They have very high energy levels, but can be made in compact and small sizes. They require a protective coating, because the material Neodymium reacts with oxygen and can get ruined if left exposed for too long. The coating needs to be thin enough so that it can’t disrupt the magnetic field. Being exposed to extremely low temperatures leads to these kinds of magnets getting damaged.
Samarium Cobalt Magnets
Like the Neodymium Iron Boron magnets, Samarium Cobalt Magnets are also rare-earth metal magnets. Although not quite as strong as Neodymium Iron Boron magnets, they still have their uses. They function better than Neodymium in higher temperatures and corrosive environments, but Neodymium magnets still have the benefit of having a stronger electromagnetic field.
Samarium Cobalt magnets are made of Samarium (Sm) and Cobalt (Co), which is why they are commonly known as SmCo magnets. SmCo magnets are used in high performance environments, where their high temperature resistance is needed. This includes motors, machinery, medical devices, etc. As you can imagine, this kind of magnet is very important in the automotive, aerospace, and military equipment industries.
Alnico magnets are a form of permanent magnet that are made of the rare-earth metals Aluminium, Nickel, and Cobalt. Alnico Magnets have largely been replaced in industrial use by NdFeB and SmCo magnets. This is because Alnico magnets are a lot weaker than its successors. They have a high magnetic strength, but they are vulnerable to demagnetization. Nowadays, they are mainly used to make sensors, guitar pickups, and other low priority equipment.
Alnico magnets are available in isotropic and anisotropic versions. The difference between eh two is that isotropic Alnico magnets can be magnetized in any direction, whereas anisotropic magnets have a particular predefined direction that they must be magnetized in. Casting is a process of creating Alnico magnets in various shapes and sizes.
Ferrite magnets are also called ceramic magnets. This is actually a non-metallic magnet! Instead, it is made of 90% iron oxide and 10% strontium carbonate, as well as other metal oxides. These materials are useful because they are very abundant, so the magnet is easy and cheap to produce. Unfortunately, Ferrite magnets are extremely fragile, and have a tendency to crack or break easily. They do, however, have the benefit of having a good magnetic field, so they do not get demagnetized very easily. The magnets are also resistant to heat and corrosion.