Dysprosium composition

In case of crystals of Cu-Dy composite formed under sonication, the concentration of dysprosium increased while in case of the crystals of Mn-Dy and Co-Dy composites, the concentration of dopant, Dy, decreased indicating a strong attraction of Dy for Cu compared to its weak interaction for Mn and Co ions. Nevertheless, the possibility of some of the Dy having been ejected out due to forceful cavitational effect of the ultrasound from the lattice of Mn and Co cannot be ruled out. Higher percentage of Cu, Mn, and Ce in case of Cu-Ce, Co-Ce and Mn-Ce composites, synthesized under sonication compared to normal crystals, could be attributed to the change in the composition of the lattice pattern due to the mechanical impact of ultrasound, whereas, such an effect has not been found in Co salts. These can be seen in Table 11.1. 

In case of Cu-Dy composites (Table 11.1) dysprosium concentration is higher in sonicated condition in comparison to normal condition, whereas, in case of Mn-Dy... 

Dysprosium combines with several nonmetals at high temperatures forming binary compounds with varying compositions. Heating with hydrogen produces dysprosium dihydride, DyH2, and dysprosium trihydride. DyH3. With sulfur, several sulfides have been synthesized that have the compositions... 

In the chemistry of the fuel cycle and reactor operations, one must deal with the chemical properties of the actinide elements, particularly uranium and plutonium and those of the fission products. In this section, we focus on the fission products and then chemistry. In Figures 16.2 and 16.3, we show the chemical composition and associated fission product activities in irradiated fuel. The fission products include the elements from zinc to dysprosium, with all periodic table groups being represented. 

The chemical composition of rare earth complexes cannot by itself reveal the coordination number of the central metal ion. There are many complexes containing hydrated water molecules and coordinated water molecules. The nitrilotriacetic acid (NTA) complexes of Pr and Dy have the formulae PrNTA 3H2O and DyNTA 4H2O, respectively. The praseodymium complex is a nine-coordinate system with one molecule of water in the hydrated form [12] and the dysprosium complex is eight-coordinate with two molecules of water of hydration [13]. These structures cannot be predicted from the composition of the complexes. The complex Nd(N03>3 4DMSO is ten-coordinate [14] since the nitrate... 

For example, the isotopic composition and the atomic weight of neodyminm," dysprosium and erbium have been determined using synthetic mixtnres prepared gravimetrically from highly enriched isotopes of neodymium in the form of oxides of weU defined pnrity by TIMS. No natnral isotopic variation was found in terrestrial neodymium, dysprosium or erbium samples. These isotopic compositions of Dy and Er measnred by TIMS are accepted as the best measurements from a single terrestrial source as noted in the table of isotopic composition of elements, 2001. °... 

Lanthanide (III) Oxides. The lanthanide(III) oxides will be used to illustrate the present breadth of our most extensive knowledge of the chemical thermodynamics of lanthanide compounds. Cryogenic heat capacities of hexagonal (III) lanthanum, neodymium, and samarium oxides, together with those of cubic (III) oxides of gadolinium, dysprosium, holmium, erbium, and ytterbium, have been reported (90, 91, 195). In addition, those of thulium, lutetium, and a composition approaching that of cerium (III) oxide have also been determined, and five well-characterized compositions between PrOi.714 and PrOi.833 are currently under study (J93). 

Over a period of more than a cenmry, chemists argued about the composition of yttria. Eventually, chemists agreed that yttria is actually a combination of nine different elements that had not been seen before. One of those elements is dysprosium. Dysprosium was finally proved to be a new element in 1886 by French chemist Paul-emile Lecoq de Bois-baudran (1838—1912). The name chosen for this new element comes from the Greek word meaning difficult to obtain. ... 

Note that the composition assigned to the amorphous phase disagrees with the composition of the equilibrium phase at 373 K. As an amorphous phase is apparently formed when dysprosium selenite is precipitated from aqueous solution at 298 K, the result of this investigation is included in the review but not selected. 

Normal azides are not known in group IIIB. Curtius and Darapsky [135] attempted to make them by dissolving, for example, lanthanum hydroxide in hydrazoic acid. The solution was assumed to contain the normal azide but only basic products were precipitated upon evaporation or by adding alcohol. The precipitate was insoluble in water, had the approximate composition La(OH)(N3)2 I.5H2O, and deflagrated upon heating. The same results were found with yttrium, cerium, dysprosium, thorium, and uranium azides. Based on the infrared spectra, Rosenwasser and Bryant [136] suggested two types of basic rare earth azides. The lanthanum type (a) was found for lanthanum, neodymium. 

Recycling rare earth magnets (NdFeB) recovers the material mostly in the composition it was originally in, e.g., Nd2Fei4B, while REEs used as glass colorant require expensive processing to produce them in the oxide form (in which they are usually traded). This, however, does not take into account the amounts of minor additions to the magnet material for specialist use, for instance dysprosium and terbium. 

For all preparations of the dysprosium and ytterbium compounds as well as the compounds of M = Ga, Pb, second phases appear in the samples, showing that the compounds R3MC,. have an x value less than unity. From observations of the changes in lattice parameters with composition in the compound Nd3lnC, the limiting... 

As work progressed they found that dysprosium additions to the TbFe2 compound would allow one to use lower magnetic fields to produce the strain with some degradation in the total strain achieved. The optimum composition chosen was Tbo.3Dyo,7Fei 9 and is now known as terfenol-D . 

Values from the 2001 table Pure Appl. Chem., 2003, 75 1107-1122. The values of zinc, krypton, molybdenum, and dysprosium have been modified. The approved name for element 110 is included see Pure Appl. Chem., 2003, 75 1613-1615. The proposed name for element 111 is also included. Reproduced from http //www.chem.qmul.ac.uk/iupac/AtWt/. The table is also available from mirror sites in Germany, Japan, South Africa, and USA. World Wide Web version of atomic weight data prepared by G. P. Moss, originally from a file provided by D. R. Tide. Note The claim [Phys. Rev. Lett., 1999, 83 1104) for elements 116 and 118 has been withdrawn (see Chem. Eng. News, 2001, 79 10 (6 August 2001) 2002, 80 12 (22 July 2002) Phys. Rev. Lett., 2002, 89 039901). Previous values may be consulted from the 1993 table, the 1995 table, the 1997 table or the 1999 table. The original paper should be consulted for details of the half-life of the radioisotopes quoted below. Also there is a report on the different isotopic compositions of some non-terrestrial materials. A number in parentheses indicates the uncertainty in the last digit of the atomic weight. 

Another interesting structure was found in the AX/RX3 (A = K, Rb X = Br, I) systems with dysprosium and thuhum for the composition A5R3X12. These... 

No systematic studies have been performed for the ternary Dy-Os(Ir, Pt)-Ge systems. Interaction of dysprosium with osmium (irridium, platinum) and germanium has been studied only with respect to the formation of compounds with a specific composition and structure. The crystallographic characteristics are listed in table 28. 

The lattice spacings in the dysprosium-holmium system are shown in fig. 104. The adjusted data of Sirota and Semirenko show a small scatter around the Vegard s law line for the a lattice spacings and a positive deviation from Vegard s law behavior for the c lattice spacings. However, the data presented by Spedding et al. show a variation of a and c with composition that is essentially linear and obeys Vegard s law. 

Fig. 14.128. The variation of the ordering temperature and critical field with composition of Dy-Co compounds. The magnetization at 160 kOe is given as a rough indication of anisotropy effects. Elemental dysprosium is shown in the form of filled squares with the ordering tempera ture normalized to the Tc curve (Taylor and Primavesi, 1972a).

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