Фазовая диаграмма системы Na-Rb

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Na-Rb (Sodium-Rubidium) C.W. Bale The assessed Na-Rb system is a simple eutectic phase diagram. The diagram was taken directly from the detailed thermal analysis of [70Goa], except for the melting points of the pure metals, which were taken from [Melt]. The subeutectic metastable liquidus indicated by the dashed lines was calculated using thermodynamic parameters. There are three stable phases in the Na-Rb system at 1 atm total pressure ( above 240 K): (1) the liquid; (2) the solid Na; and (3) the solid Rb. There is little solid solubility of Na in (Rb) and vice versa. Except where otherwise noted, the data are judged to be accurate to с0.15 K. The most inaccurate region is the steep portion of the curve immediately on the Na-rich side of the eutectic, where the uncertainty is estimated to be as high as с0.5 K [70Goa]. For most compositions, the agreement of the liquidus temperature is generally within 1 K. Time-temperature heating and cooling thermal analyses were reported by [70Goa] on an alloy sample (32.8 at.% Rb) that was subjected to pressures up to 60 000 atm. The eutectic halt increased from 269 K at 1 bar (1 atm) to 397 K at 60 kbar (60 000 atm). Pressure does not bring about the formation of a Na2Rb intermetallic compound. 70Goa: J.R. Goates, J.B. Ott, and C.C. Hsu, Trans. Faraday Soc., 66, 25 (1970). Published in Bull. Alloy Phase Diagrams, 3(3), Dec 1982. Complete evaluation contains 1 figure, 2 tables, and 10 references. 1