Фазовая диаграмма системы Ba-Yb

К оглавлению: Другие диаграммы (Others phase diargams)


Ba-Yb (Barium-Ytterbium) K.A. Gschneidner, Jr. and F.W. Calderwood The assessed Yb-Ba phase diagram is based primarily on the work of [78Zuk], with some modification. The melting temperatures for Yb and Ba have been adjusted to the accepted values, 819 and 727 C, respectively. The locations of the curves in the present diagram were obtained by scaling the phase diagram of [78Zuk] and prorating the difference between the reported and the accepted melting temperature of the end members on the basis of the mole fraction of each component at a given point. In addition to the bcc phase, [78Zuk] reported an additional fcc phase, which corresponds to (bYb). (aYb) has the dcph structure and forms from fcc (bYb) on cooling to -13 C. No binary compounds were reported. Alloying of Yb with Ba and vice versa lowered the melting point of the compounds to a minimum of ~560 C at a composition of 55 to 65 at.% Ba. Ba has lomited solubility in the fcc Yb phase. [78Zuk] reported a two-phase area where exist together extending from about 12 to about 25 at.% Ba at room temperature. The area of two-phase coexistence narrows as temperature is increased and shifts to higher Yb concentrarions, reching 100 at.% Yb at 795 C, the temperature of the b = g transformation in pure Yb. The fcc phase is stable in solid solution up to about 20 at.% Yb [71Jul]. 71Jul: R. Julliena and D. Jerome, J. Phys. Chem. Solids, 32, 257 (1971). 78Zuk: M.A. Zukhuritdinov, A.V. Vakhabov, and T.D. Dzhurayev, Izv. Akad. Nauk SSSR, Met., (2), 225 (1978); TR: Russ. Metall., (2), 179 (1978). Published in Bull. Alloy Phase Diagrams, 9(3), Jun 1988. Complete evaluation contains 1 figure, 1 table, and 6 references. 1