Consisting of a group of 15 lanthanide elements plus yttrium, the rare earth elements are all metals, grouped together on the periodic table due to their similar properties.
What sets these elements apart from others on the periodic table is the arrangement of their outer electrons. These electrons can change energy states and release visible light (fluorescence). They can absorb light or UV rays and re-emit the energy as a red or green glow. Additionally, many of the elements of this group have strong magnetic properties. When alloyed with other metals, the result is a very compact, yet strong, magnet.
It is these two main properties that have made these elements highly desirable in the production of today’s high technology devices.
Color televisions use europium and yttrium oxides to produce red colors and praseodymium and neodymium to reduce glare on screens. Cameras and binoculars with optical lenses are made with lanthanum oxide while other lanthanide compounds are used in high-intensity lighting and even street lights.
Because of their rich and varied optical properties, rare earth elements are used in glazes for earthenware (adding erbium oxide produces a pink lemonade hue). Europium, the most visible of all the rare earth elements, emits blue and red light when added to phosphors used in the production of computer monitors (even those in small, personal devices such as iPods and cell phones).
Their magnetic property has made them useful in green technology as well. Wind turbines use lanthanide-flecked supermagnets to generate electricity. Auto engines are being made more efficient by using an iron alloy of terbium and dysprosium. This blend expands and contracts efficiently in the presence of a magnetic field, helping sensors, actuators and injectors to perform better. Car batteries used in electric-powered vehicles also rely heavily on rare earth elements.
The technology explosion of the past two decades has seen a rise in demand for rare earth elements. These elements are mined in many areas around the world, including countries such as Brazil, India, China, Vietnam, the United States, Nigeria and Canada. Currently, China has the largest operations available for the mining and processing of rare earth elements. It is expected that more operations will be developed around the world in the near future as demand for high-technology devices rises and because future uses are being explored in fields such as laser technology, telecommunications and medical diagnostics.
Originally Published in Headline Discoveries