Rare Earths Crucial Elements of Advanced Technologies

Aldrich brand products are sold through Sigma-Aldrich, Inc. Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product for its particular use. See reverse side of invoice or packing slip for additional terms and conditions of sale. All prices are subject to change without notice. Introduction Welcome to the second issue of Material Matters™ for 2011, Rare Earths—Crucial Elements of Advanced Technologies. This issue highlights the Rare Earth Elements (REE), which are essential components of modern technology and find use in numerous applications such as data storage devices, lasers, phosphors for advanced displays, catalysts, permanent magnets, and petroleum refining. Rare Earth Elements have contributed to the digital revolution and have enabled a variety of emerging technologies, including hybrid electric vehicles and miniaturized devices and electronics. The Rare Earth Elements are comprised of the fifteen members of the lanthanide series (lanthanum through lutetium) and yttrium. Due to similarities in chemical behavior and mineralogical occurrence, scandium is also usually included in this classification. It should be noted that the term " Rare Earth " is somewhat misleading, as these elements are not really scarce in the context of crustal abundance, especially when compared to precious metals such as gold and platinum. 6 The extraction of REEs, however, is hardly a trivial matter: these elements are rarely observed in highly concentrated, minable deposits. Furthermore, REEs are commonly found together—thus the term " fraternal fifteen " (lanthanide elements)—in rock-forming minerals, which necessitates quite sophisticated processes for separations. 7 Sigma-Aldrich® has a long history of expertise in REE processing and offers a range of different grade materials to serve a variety of customers. In 1996, Sigma-Aldrich was identified by the U.S. Geological Survey as a key producer of high-purity scandium metal, oxide, and fluoride. 8 In the following years, however, in-house processing of REE oxides and metals has been reduced due to the broad availability of very inexpensive materials from international markets. We have recently resumed our operations to meet rising demand for REEs, which is expected to grow continuously through the next several years. who discusses the historical production of REE materials and their current shortage in the global market. In the following article, Julia Chan (Louisiana State University) describes highly correlated lanthanide intermetallics, providing an overview of material properties and a brief analysis of the molten metal flux …