Lanthanides

Abstract

Lanthanides, formerly known as rare earths, are critical materials. Their discovery, extraction and refining are described. The important role China has in refining is outlined, as is its dominant role in production of components such as extremely powerful permanent magnets based on neodymium–iron–boron alloys. Simplified flow charts are given for refining these materials, as are the formation of potentially toxic waste streams on purification. Chemical properties of rare earths are outlined, as is the lanthanide contraction. As in other chapters, supply chains and geopolitical issues for lanthanides are explained. Applications for lanthanides are described with emphasis on permanent magnets as they are used in electric vehicles and wind turbines. Possible high-temperature ceramic superconductors based on lutetium-containing materials are outlined, as is the use of critical materials, including lanthanides in the pharmaceutical area. The use of radioactive isotopes in medicine is briefly described, as are studies on lanthanide-free permanent magnets. The importance of lanthanides as powerful, small magnets in loudspeakers for smartphones and ‘ear buds’, use of lanthanides as components in cruise missiles, drones and smart bombs are given with other examples of their applications.