what

What are Rare Earth Elements?

Physical Properties
Rare earth elements are a group of elements on the periodic table: the 15 Lanthanides, as well as Scandium and Yttrium. Elements in the REE Group exhibit common properties of:

Magnetism

Catalysis

Phosphorescence

Critical REEs
Interestingly, only about 25% of REE properties are shared by the group, where 75% of exhibited properties are unique to the individual element. In 2011, the US Department of Energy designated 5 REEs as being critical to national strategy. Lets take a look at these REEs and find out what makes them so important:

Neodymium (Nd)

Dysprosium (Dy)

Europium (Eu)

Terbium (Tb)

Yttrium (Y)

What are Rare Earth Elements Used For?

Applications
REEs are not useful on their own. They are typically used as an additive, or agent of change. When an REE is added to a mixture of other metals, an alloy is formed. Sometimes components are "doped" with an REE to give it a super function, such as adding Erbium to fiber optic cable to amplify the light pulses. Let us explore the more common applications of REEs:

"Green" Energy: Wind turbines and electric motors are going to need magnets, really strong ones. Rare earth elements fill this role. Joe Biden wants 500 thousand electric vehicle charges installed nation wide by 2030. The production of 500,000 electric vehicles will require 1 million kg of Neodymium magnets alone. This does not include the REE found in the Ev's batteries.

Oil Refining Catalyst: 60% of domestic REE consumption is used up by oil refining. The addition of select rare earths in the cracking process of the long chain hydrocarbons found in crude substantially speeds the refining process.

Consumer Electronics: Rare earth elements are found in every single electronic device you own. Perhaps in trace amounts, but they're there and they are necessary.

Glass: This is my favorite use of rare earths. Glass produced with neodymium oxide changes color depending on the wavelength of light passing through it. This is caused by neodymium's spectrum of sharp absorption bands. Daylight creates a purple-red color, incandescent light a yellow color, fluorescent light a blue color, and trichromatic light a green color. If your wine glass is a purple-red color, then you know it is still too early to be using it.

Laser Beams: Concerning REEs, a laser beam is composed of two parts. These are the host crystal matrix and the ion of the beam. When using a rare earth element as the ion, the quantum energy level of the beam remains constant no matter the constitution of the host crystal matrix. The quantum energy level of the laser beam is a fancy way of saying the "wavelength" of the beam. This consistency of wavelength no matter the host crystal material is highly prized in the laser world.