Rare earth metals are actually not rare- some of them are more abundant than lead and other common metals. However, they are not usually found in large quantities, and they are rarely found alone. More often, they are found scattered around, mixed up with each other and other metals, and in sufficiently small quantities so as to make them expensive to mine and process. They are increasingly important in modern technology and both light and heavy rare earths are used in everything from airplane frames to computer chips to electric motors.
Most of the rare earth metals are found in one group on the periodic table and are called lanthanides. Lanthanides have similar characteristics and are usually found together in the same ores. They are chemically very similar, and most are magnetic and can be used in metal alloys as well as other uses.
Lanthanum
The first of the lanthanides is lanthanum. Lanthanum is one of the most common of the rare earths and is commonly found in a mixture with other rare earths such as cerium. This mixture is known as ‘mischmetal” and can be used in a variety of applications. It is often found in the ground in this mixture and can be used in applications that glow, such as lantern mantles and night-vision goggles. Despite its classification as a rare earth, lanthanum isn’t actually rare, and there is more of it in the earth than there is lead.
Cerium
Cerium, like Lanthanum, is not rare. There is about as much of this element as there is copper, and more than there is of lanthanum. Cerium sparks easily, and is used in lighter flints and for special effects in movies. It is also an important ingredient used to make catalytic converters. In addition, it’s used in small amounts in alloys.
Praseodymium
Praseodymium makes very strong metals that are used to make aircraft engines. It is also used to make special glass goggles to protect the wearer’s eyes from the brightness of glassblowing and welding torches. This is because the glass absorbs a lot of yellow light. This makes the glass look blue but also has the effect of eliminating the glaring yellow of bright flames, making it possible for welders and glassblowers to look at their work without damaging their vision.
Neodymium
Neodymium is mostly used to make strong and permanent magnets. These magnets are so powerful that they can be used in a huge variety of applications. They can also be dangerous as they can attract each other more than a foot away, and heavy ones can injure people as they fly toward each other. In practical applications, they are used for the magnets in speakers and computers, as well as eco-energy applications like electric cars and wind turbines.
Samarium
Samarium makes a powerful magnet when combined with cobalt. It isn’t the strongest magnet on earth, but it is one of the strongest that is also highly heat-resistant. It is used in microwaves for that reason. It can also be used interchangeably in many of the applications that the other rare earth metals are used in.
Europium
This element is used to make things glow. It is used to make phosphorescent paint, old-fashioned vacuum tube televisions, fluorescent lightbulbs, and control rods for nuclear reactors. It plays a role in creating screens, light bulbs, and other luminous things.
Gadolinium
Gadolinium is used as a contrast medium in MRI scans. This means that it is injected into the blood and can show where the blood is going because, unlike the blood itself, it shows up darkly on an MRI image. This can be used to take a picture of an abnormal bleeding situation, look for tumors, and other medical applications.
Terbium
Terbium, along with Europium and Yttrium, is used in screens, displays, and other places where it can be used to create the effect of different colors. It is also used to help in the production of solid-state hard drives and low-energy bulbs. One of the most interesting things about terbium is its property of lengthening and shortening when it’s in a magnetic field. This is even more prominent when it’s made into an alloy with dysprosium and iron. It is used in this form to create loudspeakers.
Dysprosium
Besides its use in the alloy mentioned above, dysprosium is also used in nuclear control rods like many of the other rare-earth metals. It is becoming an important element in the green technology market to help make wind turbines, electric vehicles, and generators. It is used in an alloy with neodymium to make heat-resistant and powerful magnets to be used in motors.
Erbium
Erbium, like many of the other rare earths, is used most commonly in an alloy. It is also used to make control rods for nuclear reactors and has a unique use in fiber-optic cables where it can actually help amplify the light that comes out of a fiber-optic strand. This is done with the use of an interesting device called an erbium-doped fiber amplifier. Less dramatically, erbium can also be used to tint glass pink.
Yttrium
Yttrium is one of the metals that is considered a rare earth metal not because it is a lanthanide, but because it is often found in the same ore with them and has similar properties. Yttrium is important in making radar, in adding strength to magnesium and aluminum alloys, and superconductors. It can be used to make lasers that can cut metal, treat cancer, and make glass more shock-resistant. It has also been used to help make color television. It’s a very versatile element!
Scandium
This element, like yttrium, is considered a rare earth that is not a lanthanide. It is used to make strong aluminum alloys that are used in things like fighter jets. It can also be used to make metal-halide lights.