Gadolinium Encyclopedia Article

Gadolinium

The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.

(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.

The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.

The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.

All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.

Gadolinium

Gadolinium is a metal element that has a silvery luster with a pale, yellowish cast. Its atomic number is 64, atomic weight, 157.25, atomic symbol, Gd, melting point, 2,395.4 °F (1,313°C), and boiling point, 5,923.4°F (3,273°C). The metal is moderately active. It is stable in dry air, but tends to oxidize in moist air.

The discovery of gadolinium began with the work of Johan Gadolin (1760- 1852). He was an important figure throughout the history of the discovery of rare earth elements. In 1794, the Finnish chemist completed the first analysis of ytterite, a mineral found near the town of Ytterby, Sweden, in 1787. Gadolin found that ytterite contained about 38% of a new substance. In honor of this discovery, ytterite was later renamed gadolinite.

More than a century was to pass before chemists completely analyzed the composition of gadolinite. Along the way, they discovered 14 new elements. One of those elements was found in 1880 by the Swiss chemist Jean-Charles Galissard de Marignac (1817-1894). Marignac discovered that one fraction of gadolinite known as yttria contained a previously unknown element which he tentatively called Ya. Six years later, the same element was rediscovered by Paul Émile Lecoq de Boisbaudran. Boisbaudran proposed naming the element gadolinium for the mineral in which it was found, a decision with which Marignac agreed.

Gadolinium is the most efficient substance known for the capture of neutrons. This property would seem to make it useful in control rods in nuclear power reactors. But since the two (out of seven) isotopes most responsible for this property are in low abundance, the metal has had relatively little application in this field.

Gadolinium becomes highly magnetic at very low temperatures and shows unusual properties of superconductivity under similar conditions. The element is used in the manufacture of garnets used in microwave filters and in phosphors used in color television sets. The addition of small quantities of gadolinium to other metals and metallic mixtures improves the workability of these materials and their resistance to corrosion.