Neodymium properties

Another material that has permanent magnetic properties is neodymium—iron—boron, Nd2Fe24B. For an in-depth discussion see reference 7. 

The valences of the rare-earth metals are calculated from their magnetic properties, as reported by Klemm and Bommer.14 It is from the fine work of these investigators that the lattice constants of the rare-earth metals have in the main been taken. The metals lutecium and ytterbium have only a very small paramagnetism, indicating a completed 4/ subshell and hence the valences 3 and 2, respectively (with not over 3% of trivalent ytterbium present in the metal). The observed paramagnetism of cerium at room temperature corresponds to about 20% Ce4+ and 80% Ce3+, that of praseodymium and that of neodymium to about 10% of the quadripositive ion in each case, and that of samarium to about 20% of the bipositive ion in equilibrium with the tripositive ion. 

Recently similar complexes of neodymium have been prepared by Karraker 48) containing bromide and iodide in place of chloride. While their chemical properties are similar to the dimeric chloride compound their powder patterns suggest they may have different structures. Since they also have increasing amounts of solvent, the bromide containing three THF molecules and the iodide four, these may be complexes in which the halide bridge is broken by addition of another solvent molecule to give a monomer such as [Ln(COT)X 3 THF]. 

Supported Ziegler-type neodymium surface species (54, see below) have been prepared by mixing molecular components composed of [Nd(naph)3] (derived from naphthenonic acids) and alkyl aluminium reagents such as Al2Et3Cl3, Al( Bu)3 and/or Al( Bu)2H at 50-60°C with silica (source QiLu Petrochemicals Co., China) [158-160]. Although the immobihzed neodymium species are iU-defined, the materials display interesting properties in butadiene polymerization (Section 12.4.1.2). 

Elemental composition Nd 85.73%, 0 14.27%. The oxide may he characterized hy x-ray diffraction and fluorescent properties. Neodymium may he analyzed in an acid extract of the oxide hy ICP-AES or ICP-MS techniques under appropriate dilution of the extract. 

NdjlCufpballj 23H2O, 43 208-210 Negative ion spectra, 28 7 Neocuproine copper complexes, 45 289 Neodymium carbides, 11 200 dibromide, 20 4 dichloride, 20 4 preparation of, 20 8 properties of, 20 15-18 diiodide, 20 4... 

These same researchers also explored the efficacy of the individual rare earths as nodulizers (17). They concluded, by their ability to produce nodular iron having adequate physical properties without excessive iron carbides present, that cerium was the most effective of the four rare earth elements (lanthanum-neodymium) evaluated as nodulizers. They reported that it required 1.5 times as much neodymiun or praseodymium and three times as much lanthanum as cerium to yield equivalent results. 

Similar results were obtained by Zhu et al. [222], who have investigated the influence of lanthanum and neodymium hydroxides on the properties of secondary alkaline zinc electrode. 

Fluorescent and Physical Properties of Neodymium-Doped Alkali Silicate and Germanate Glasses... 

Many aryl-substituted pyrylium salts are intensely fluorescent. It is possible to predict these spectral properties by a consideration of the shape of the molecule, the nature of substituents and the length of the ir-electron system (75MI22203). Pyrylium salts have been used as Q-switches for neodymium and ruby lasers in acetonitrile (68MI22200). 

Other important physical properties of neodymium are given under Rare-Earth Elements and Metals. 

RARE-EARTH ELEMENTS AND METALS. Sometimes referred to as the fraternal fifteen," because of similarities in physical and chemical properties, the rare-earth elements actually are not so rare. This is attested by Fig. 1, which shows a dry lake bed in California that alone contains well in excess of one million pounds of two of die elements, neodymium and praseodymium. The world s largest rare earth body and mine near Baotou, Inner Mongolia, China is shown in Fig. 2. It contains 25 million tons of rare earth oxides (about one quarter of the world s human reserves. The term rare arises from the fact that these elements were discovered in scarce materials. The term earth stems from die tact that the elements were first isolated from their ores in the chemical form of oxides and that the old chemical terminology for oxide is earth. The rare-earth elements, also termed Lanthanides, are similar in that they share a valence of 3 and are treated as a separate side branch of the periodic table, much like die Actinides. See also Actinide Contraction Chemical Elements Lanthanide Series and Periodic Table of the Elements. 

The luminescence properties of the decatungstolanthanate anions, especially [Eu(W5Oi8)2]9 , have attracted considerable attention, both in the solid state and solution (Blasse et al., 1981a, 1981b Blasse and Zonnevijlle, 1982 Ballardini et al., 1983 Darwent et al., 1986 Blasse, 1988 Sugeta and Yamase, 1993 Ozeki and Ya-mase, 1993c Lis et al., 2003). Electroluminescence cells based on alkaline earth metal salts of the europium anion have been described (Yamase and Ueda, 1993) and the results of pulse- and continuous-radiolysis of solutions of the europium and neodymium anions have been reported (Mulazzani et al., 1985). 

---