Everyday Uses of Lanthanides: The Rare Earth Elements
August 5, 2020 - Emily Newton
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If you look at the periodic table, can you identify the elements known as lanthanides? Don’t worry if you can’t — they’re not a type of element you’re likely to encounter on your daily walk through the park. Also known as rare earth elements, these 15 elements all fall between the atomic numbers of 57 and 71 and have their own section on the bottom of the periodic table. What are lanthanides and where might you encounter them in your everyday life?
Lanthanide Properties
First, let’s take a look at the elements that make up the lanthanide group. In spite of the group’s nickname—”rare earth elements”—these elements aren’t all that rare. The 15 elements are as follows:
Atomic No. 57-61 | Atomic No. 62-66 | Atomic No. 67-71 |
---|---|---|
Lanthanum | Samarium | Holmium |
Cerium | Europium | Erbium |
Praseodymium | Gadolinium | Thulium |
Neodymium | Terbium | Ytterbium |
Promethium | Dysprosium | Lutetium |
The only exception to this abundance is promethium because it is produced artificially in the lab.
Occasionally, scandium and yttrium are included in this group, but we’ve already discussed these in a previous piece, so we’re going to leave those two out of this discussion.
Chemical and Physical Traits of Lanthanides
While lanthanides are fairly common in the Earth’s crust, they tend to be very difficult to extract in usable quantities. These elements are bright and usually silvery — at least until they are exposed to oxygen. They are highly reactive, and while they’re not explosive, they tarnish quickly — which also makes them susceptible to contamination from other elements.
Not all lanthanides tarnish at the same rate. Lutetium and gadolinium, for example, can be exposed to air for long periods without tarnishing, while elements like lanthanum, neodymium and europium are highly reactive and must be stored in mineral oil to prevent tarnishing.
All members of the lanthanides group are extremely soft. Most can be easily cut with a knife and don’t require any heavy-duty tools to remove them from the earth.
These elements aren’t considered rare because they’re hard to find. They’re rare because it is difficult to extract sufficient quantities of the pure form of each element to meet any and all industrial needs.
Real-Life Applications
Where can you encounter these rare earth elements in your daily life, other than in a lab? Common uses of lanthanides can be found in lamps, lasers, magnets, and more. They’re also used in a lot of manufacturing processes, including those for petroleum and steel.
Cerium
Ceres is a dwarf planet in the asteroid belt that, among other things, serves as a major setting in “The Expanse” television show. It also lends its name to the first lanthanide on our list — cerium. Scientists found cerium in 1803, and while it only makes up 0.0046% of the Earth’s crust, it is still the most abundant of the rare earth elements on the planet. It is incredibly soft, easily scratched with metal tools and objects, but has several limited applications.
Uses for Cerium
- Carbon arc lighting: Cerium is a key component in carbon arc lights, ultrabright light sources that are popular in the motion picture industry.
- Lighter flints: Cerium is often one of the primary components in mischmetal, which you’ll find in lighter flints.
- Glass manufacturing: In the glass industry, cerium finds uses as a polishing agent and decolorizer, removing pigment from the glass. It’s even possible to reclaim the cerium from glass polishing waste, making it eco-friendly.
Gadolinium and Yttrium
Gadolinium and yttrium are two raw materials that are almost always found together. The same researcher discovered both in the late 1700s. Here are some uses of these elements.
Uses for Gadolinium and Yttrium
- Television phosphors: Both elements are often found in older televisions, lending color to the devices in the form of phosphors. Yttrium, in particular, creates a vibrant red shade.
- Artificial garnets: Scientists can create synthetic garnets by combining gadolinium and yttrium, but these aren’t the gems you’ll wear in jewelry. Instead, they’re used in microwave technology.
- Nuclear control rods: Gadolinium is the best element on the planet for capturing neutrons, making it an excellent choice for nuclear control rods. Unfortunately, the two gadolinium isotopes that work best for this are in short supply.
Lanthanum and Samarium
Scientists discovered lanthanum almost by accident. In 1839, a Swedish chemist was looking for impurities in cerium and discovered an entirely new rare earth metal. Its name comes from the Greek word lanthaneia, meaning “to lie hidden.” It’s an appropriate moniker for an element that was hiding inside cerium. Samarium, on the other hand, got it’s name from samarskite, the mineral from which scientists extract the element.
Uses for Lanthanum and Samarium
- Absorbing hydrogen: Lanthanum is another element that can absorb massive amounts of another. In this case, it’s capable of absorbing more than 400 times its volume in hydrogen.
- Lighter flints: Like cerium, lanthanum is also a component in the mischmetal that makes up lighter flints. Most flints contain between 25-45% lanthanum. Samarium makes up about 1% of these flints.
- Glass manufacturing: Lanthanum and samarium both improve the alkali resistance of glass, making it an excellent choice for manufacturing specialty lenses such as those used in cameras and telescopes.
Erbium, Terbium and Europium
These last few rare earth elements don’t have many applications. However, there are still a few uses for these metals.
Uses for Erbium, Terbium and Europium
- Glass and porcelain tints: Erbium is the primary component in pink pigments for glassmaking and porcelain tints.
- Television phosphors: When you expose terbium to electrons, it glows a brilliant green and is often used as a phosphor in televisions.
- Postage stamps: A little bit of europium goes a long way, and allows post offices to scan stamps electronically.
The rest of the elements in this group have little to no practical application. They’re reactive and expensive to mine. You may find them in televisions as phosphors or in nuclear reactors. They’re certainly not the kind of raw material you’ll see in your local grocery or department store.
Have you spotted any lanthanides in your everyday life? Let us know! If you’ve got any questions about these rare earth elements, feel free to reach out. We’d love to hear from you! What is your favorite element from the lanthanide group?
This article originally published 04/06/2018. We updated it on 08/05/2020 to expand the section of Real Life Applications with more in-depth uses of lanthanides.
Revolutionized is reader-supported. When you buy through links on our site, we may earn an affiliate commision. Learn more here.
Author
Emily Newton
Emily Newton is a technology and industrial journalist and the Editor in Chief of Revolutionized. She manages the sites publishing schedule, SEO optimization and content strategy. Emily enjoys writing and researching articles about how technology is changing every industry. When she isn't working, Emily enjoys playing video games or curling up with a good book.