SAMPLE PREPARATION AND CHARACTERIZATION FOR PHYSICAL MEASUREMENTSFrom commercial actinide oxides to single crystals of their metals and refractory compounds

J. Spirlet

Commercial actinide oxides, after purification by standard procedures (extraction chromatography, precipitation, etc.) are reduced to metals. The actinide metals Am, Bk, Cf, Es are obtained by metallothermic reduction in vacuum with lanthanum metal, Cm, Ac, Pu by the same process with Th metal as reductant. U, Np, Pu metals are prepared by tantalothermic reduction of the carbides. These volatile metals are efficiently refined by repeated evaporation and condensation. Pa and Th are prepared in a pure form in a van Arkel process by thermal dissociation of their iodides starting from the carbide. Large single crystals of the more volatile metals (Am, Cm) are prepared by physical vapour deposition and annealing at high temperature. Single crystals of Th and Pa are obtained by chemical vapour deposition with I2 as transporting agent. Pure actinide compounds in powder form are prepared by direct synthesis from the elements. Composition and structure of the compouds can be controlled by the reaction conditions. Single crystals of the actinide, dioxides, dipnictides and dichalcogenides are produced by chemical vapour transport with TeCl4 or I2 as transporting agent. Monopnictide single crystals are prepared by chemical vapour deposition using the van Arkel process. The crystals are characterized by chemical analysis and X-ray diffraction (Debye-Scherrer, Weissenberg, Laue) techniques.

Domaines: Articles anciens

J. Spirlet. SAMPLE PREPARATION AND CHARACTERIZATION FOR PHYSICAL MEASUREMENTSFrom commercial actinide oxides to single crystals of their metals and refractory compounds. Journal de Physique Colloques, 1979, 40 (C4), pp.C4-87-C4-94. ⟨10.1051/jphyscol:1979429⟩. ⟨jpa-00218825⟩