Uranium magnetic properties

Complexes. The structure of an n a charge-transfer complex between quinoxaline and two iodine atoms has been obtained by X-ray analysis and its thermal stability compared with those of related complexes. The hydrogen bond complex between quinoxaline and phenol has been studied by infrared spectroscopy and compared with many similar complexes. Adducts of quinoxaline with uranium salts and with a variety of copper(II) alkano-ates have been prepared, characterized, and studied with respect to IR spectra or magnetic properties, respectively. 

She talked it over with Pierre. Her enthusiasm captivated him. She told her husband that, in her opinion, the increased activity of the ore from Bohemia was due to a hitherto unknown element more powerful than uranium. This substance/ she told Pierre, cannot be one of the known elements, because those have already been examined it must be a new element. Pierre was working on crystals, and she on the magnetic properties of metals in solution. Both dropped all their work to join m the great adventure of tracking down the unknown cause of the great power of pitchblende. Mendel eff, hearing of this, consulted his Periodic Table. There was room for such an element. Marie was bound to find it. 

Solid state compounds of uranium have been much studied because of their unusual magnetic properties and their inertness. They are usually made by direct interaction with uranium metal. 

Another potential use for holmium is a result of its very unusual and strong magnetic properties. It has been used in alloys with other metals to produce some of the strongest magnetic fields ever produced. Holmium also has some limited use in the manufacture of control rods for nuclear power plants. Control rods limit the number of neutrons available to cause the fission of uranium in nuclear reactors, thus controlling the amount of energy produced in the plant. 

Because of its large size and accessibility to multiple oxidation states, uranium is capable of unprecedented reactivity and beautiful coordination complexes that caimot be achieved with transition metals or lanthanides. The exciting products highlighted here demonstrate that we have only just begim to learn the capabilities of uraniiun, and that continuous studies will be needed to determine the full realm of possibiUties. From activation of small molecules to unique magnetic properties, uranium offers a synthetic and spectroscopic challenge to coordination chemists of the future. 

Binary compounds can be made with uranium. Such solids state compounds have been investigated because they have interesting magnetic properties. They are made by direct interaction with uranium metal. Oxides mainly form with the general formula UO2, UjOg, UO2. The metal also reacts with other elements such as boron, carbon, nitrogen, phosphorus, and arsenic to make semi-metallic solids. Compounds can also be made using silicon, sulfur, selenium, and tellurium. Urinates can be formed by the addition of uranium with alkali and alkaline Earth metals. 

Paramount information on structure and phase equilibria of the ThMni2 type compounds was collected by Gladyshevsky et al. (1990), while the structure and magnetic properties have been reviewed several times for rare-earth aluminides (Nowik and Felner 1983), rare-earth and actinide aluminides (Suski 1985), actinide aluminides (Sechovsky and Havela 1988), intermetallics with higher content of the iron-group metals for the rare eardis (Buschow 1991, H.-S. Li and Coey 1991), and uranium (Suski 1992). 

Recently, some theoretical works have been published concerning the electronic structure and magnetic properties of the compounds discussed. They concern not only the materials with Y but even with uranium (see e.g. Matar et al. 1994). These preliminary calculations suggest that further progress can be accomplished in this difiScult research area. 

ThN and UN are completely miscible and form a continuous series of solid solutions. Phase relations, preparation and properties (crystallographic properties, thermal conductivity, electrical and magnetic properties) of the solid solutions are described in the Gmelin Handbook, see Uranium Suppl. Vol. C7, 1981, pp. 81/2. 

Lander (1978) discusses the problem of assigning a well-determined value to the ionization of the uranium ion. Magnetization measurements in extremely high fields on powdered samples (Schinkel and Troc 1978) could not improve the understanding of the magnetic properties of UAs. The magnetization depends critically on the orientation of the applied field (Busch and Vogt 1978), since intermediate spin... 

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