Фазовая диаграмма системы Au-Pm

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Au-Pm (Gold-Promethium) H. Okamoto and T.B. Massalski The assessed Pm-Au phase diagram is based completely on the present thermodynamic calculations. The assumptions made are (1) the liquid is a subregular solution (two parameters); (2) the solid phases have no significant solid solubility; (3) the DCp values of the pure elements and compounds are all zero; and (4) the lattice stability parameters for Pm and Au are derived from the heats of transformation of the elements given by [83Cha]. The properties of Pm-Au intermetallic compounds have not been studied, presumably because of the difficulty in obtaining sufficient Pm, which does not exist in nature due to the short half-life of the element. (No known isotope of Pm has a half-life longer than 17.7 years.) Because the melting point (1042 C) and the heats of transformation [83Cha] of Pm follow the systematic variation in the lanthanide series, it has been assumed here that the Pm-Au system has the same set of intermetallic phases as the Nd-Au system. 83Cha: M.W. Chase, Bull. Alloy Phase Diagrams, 4(1), 124 (1983). Published in Phase Diagrams of Binary Gold Alloys, 1987. Complete evaluation contains 1 figure, 2 tables, and 1 reference. 1