Фазовая диаграмма системы Cu-Lu

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Cu-Lu

Cu-Lu (Copper-Lutetium) P.R. Subramanian and D.E. Laughlin No assessed phase diagram is available for the Cu-Lu system. However, the general features of the Cu-Lu phase diagram are expected to be similar to those of the other Cu-heavy lanthanide systems. Moreover, melting and eutectic temperatures in the Cu-lanthanide systems, in general, are known to vary systematically across the lanthanide series. Accordingly, the invariant temperatures of known Cu-Lu intermediate phases were estimated by extrapolation of corresponding data for those Cu-lanthanide systems for which experimental phase diagrams are already known, using the systematic methods described by [83Gsc]. The Cu-Lu phase diagram was then estimated from the extrapolated invariant temperatures, in conjunction with thermodynamic considerations. In the calculated diagram, the existence of Cu9Lu2 and Cu7Lu2 is proposed solely on the basis of the presence of similar phases in the Cu-Gd [83Car], Cu-Dy [82Fra], and Cu-Er [70Bus] systems. Because there is no experimental phase diagram information for the Cu-Lu system, the calculation of the Cu-Lu phase relationships involved the following assumptions: terminal solid solubilities are negligible; the liquid behaves like a subregular solution; and eutectic and melting temperatures represent values extrapolated from experimental data for the other Cu- lanthanide systems. The Cu-rich and Lu-rich liquidus were calculated from thermodynamic data, and the liquidus between 8 and 67 at.% Lu was estimated from systematics of Cu- lanthanide systems. 63Sto: A.R. Storm and K.E. Benson, Acta Crystallogr., 16, 701-702 (1963). 70Bus: K.H.J. Buschow, Philips J. Res., 25, 227-230 (1970). 71Ian: A. Iandelli and A. Palenzona, J. Less-Common Met., 25, 333-335 (1971). 82Fra: E. Franceschi, J. Less-Common Met., 87, 249-256 (1982). 83Car: M.M. Carnasciali, S. Cirafici, and E. Franceschi, J. Less-Common Met., 92, 143-147 (1983). 83Gsc: K.A. Gschneidner, Jr., and F.W. Calderwood, Bull. Alloy Phase Diagrams, 4(2), 129-131 (1983). Published in Bull. Alloy Phase Diagrams, 9(3a), Jun 1988. Complete evaluation contains 1 figure, 6 tables, and 14 references. Special Points of the Cu-Lu System